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Cited by 1Polymer Foaming and CompositesHygrothermal properties of building materialsNatural Fiber Reinforced Composites

Rigid Macroporous Wood Microparticles Impart Universality and Scalability to Lightweight Foam Insulation

Open access
Dobrzanski, Elizabeth, Schnell, Jonas, Zhang, Weijia, Ferreira, Elisa S., Keränen, Janne, Agrawal, Prashant, Yuan, Yufeng, Chen, Richard +2 more·2025·Advanced Sustainable Systems
DOI 10.1002/adsu.202400986
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Abstract

Foam‐formed nonwoven materials have recently experienced a surge in popularity, but research focuses on flexible fibres with scant information on rigid particles. This work showcases how rigid, minimally‐processed, macroporous wood microparticles work synergistically with the foam‐forming method to offer a robust manufacturing strategy that is insensitive to feedstock and water quality. Lightweight oven‐dried foams suitable for rigid thermal insulation are produced using four types of wood residue and can be made using ocean water instead of ultrapure water. The bio‐based content in the foam can be increased by partially/fully replacing the polymer binder with mechanical pulp or using a biosurfactant. For the 15 foams produced with slightly modulated compositions, the densities are low (90–130 kg m −3 ), the thermal conductivities are low (38–45 mW m −1 K −1 ), and many meet ASTM insulation standards for compressive strength. Pilot plant scaling produced large‐scale (100×50×4 cm) foam boards. The structure‐property relationships elucidated offer new guidelines to optimize foam performance by matching microparticle size to bubble size, having a distribution of microparticle lengths, and preserving wood's natural macroporous character. This work demonstrates how to harness the functionality that nature has already engineered for plants in the design of novel, sustainable and advanced bioproducts.

AI snapshot

Written from the paper’s full text.

TL;DR

Rigid, minimally processed macroporous wood microparticles can be foam-formed with PVA/SDS into lightweight, oven-dried insulation foams that tolerate different wood residues, binders, surfactants, and simulated ocean water. The method produced lab foams with densities of 90–130 kg m⁻³ and thermal conductivities of 0.0375–0.0453 W m⁻¹ K⁻¹, and was scaled to pilot-plant boards.

Key findings

  • Foams were successfully made from four wood residues (PBK, hemlock, red cedar, SPF), 50:50 blends, BCTMP as partial/full PVA replacement, Glucopon or TWEEN 80 instead of SDS, and simulated ocean water; rigid wood microparticles made up over 74 wt.% of dried foams.
  • For 15 lab foams, densities were 90–130 kg m⁻³ and thermal conductivities were 0.0375–0.0453 W m⁻¹ K⁻¹; some samples exceeded the ASTM C578-22 minimum compressive strength at 10% strain of 35 kPa.
  • Replacing PVA with BCTMP lowered density and thermal conductivity but reduced stiffness: Young’s modulus fell from 26.9 ± 6.9 MPa for 100% PBK to 10.8 ± 2.4 MPa for 100:0 BCTMP:PVA, while shape recovery improved.
  • Pilot-plant trials produced boards ≈1 × 0.5 m and at least 4 cm thick; nine trials gave densities of 83–104 kg m⁻³, thermal conductivities of 0.041–0.048 W m⁻¹ K⁻¹, and compressive strengths of 15–22 kPa, with three trials closely matching lab properties.

Methods

  • Lab foams were prepared by milling wood residues, dispersing them with PVA and surfactant in water, foaming with an Ultra Turrax homogenizer at 9000 RPM for 10 min, pouring into silicone molds, and oven-drying overnight at 60 °C.
  • Characterization included apparent density, transient thermal conductivity, compressive strength at 10% strain and cyclic compression, 3-point bending, x-ray tomography, ImageJ particle/cell size analysis, Klason lignin and monosaccharide analysis, and one-way ANOVA for shape recovery.
  • Pilot-scale trials were run with VTT using a 600 mm-wide non-pressed foam-forming line at 2 m min⁻¹, followed by separate oven drying; formulations varied from 50–80 wt.% wood microparticles, 5–25 wt.% PVA, 5–25 wt.% BCTMP, and 0.04–12 wt.% SDS.

Limitations

  • Stated: only some lab samples met the ASTM C578-22 compressive strength benchmark; BCTMP did not fully replace PVA’s binding ability at the tested ratios if a rigid foam is desired; more work is needed to map mechanical properties before confident predictions from bulk wood values.
  • Stated: there is an upper limit on microparticle/fibre size because large red cedar fractions and BCTMP over 600 μm clogged the lab homogenizer; pilot foams showed slight densification near the bottom and smaller cells than lab foams.
  • Evident from the text: flame, moisture, and microbial resistance were not tested and are named as possible future enhancements; long-term durability, weathering, and full economic/life-cycle assessment are not reported in the main text.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1002/adsu.202400986

Cites

58 of 58 references verified0 citation errors · 0 not checkable

Statistics

Claims the paper makes

0 of 58 cited sources checked · 0 supported · 0 flagged

  • Findingnone given

    Pilot plant scaling produced large-scale (100×50×4 cm) foam boards.

    “Pilot plant scaling produced large-scale (100×50×4 cm) foam boards.”
    Quote in the paperSubstantial claim
  • Findingnone given

    The best thermally insulating foams were those with partial or full replacement of PVA with BCTMP fibres.

    “The best thermally insulating foams were those with partial or full replacement of PVA with BCTMP fibres.”
    Quote in the paperNot a substantial claim
  • Findingown data

    Our foams follow the expected materials property relationship of thermal conductivity increasing with increasing density.

    “Our foams are designed for thermal insulation applications and were found to follow the expected materials property relationship of thermal conductivity increasing with increasing density as seen in Figure 2. [47]”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [47]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Findingreasoning

    Rigid wood microparticles retain natural macropores ≈30 μm in diameter.

    “Because the rigid wood microparticles experience very little processing, they retain their natural macropores, ≈30 μm in diameter”
    Quote in the paperSubstantial claim
  • Findingnone given

    The porosity-thermal conductivity relationship holds well in our wood foams.

    “and this relationship holds well in our wood foams.”
    Quote in the paperSubstantial claim
  • May combine two claims. 64
  • Classified as probably not a substantial claim. 27
  • The quote only partly states this claim. 2

  • May combine two claims.

    Findingown data

    Lightweight oven-dried foams suitable for rigid thermal insulation are produced using four types of wood residue and can be made using ocean water instead of ultrapure water.

    “Lightweight oven-dried foams suitable for rigid thermal insulation are produced using four types of wood residue and can be made using ocean water instead of ultrapure water.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    For the 15 foams produced with slightly modulated compositions, densities are 90-130 kg m-3 and thermal conductivities are 38-45 mW m-1 K-1, and many meet ASTM insulation standards for compressive strength.

    “For the 15 foams produced with slightly modulated compositions, the densities are low (90-130 kg m -3 ), the thermal conductivities are low (38-45 mW m -1 K -1 ), and many meet ASTM insulation standards for compressive strength.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based). May combine two claims.

    Findingnone given

    The bio-based content in the foam can be increased by partially/fully replacing the polymer binder with mechanical pulp or using a biosurfactant.

    “The bio-based content in the foam can be increased by partially/fully replacing the polymer binder with mechanical pulp or using a biosurfactant.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingnone given

    The solid component of the foam consists of rigid wood microparticles joined by PVA to form the struts and hinges of polyhedral cells, except the 100:0 BCTMP:PVA sample has PVA entirely replaced by pulp fibres.

    “The solid component of the foam consists of rigid wood microparticles which are joined by PVA to form the struts and hinges of the polyhedral cells, with the exception of the 100:0 BCTMP:PVA sample, which has its PVA entirely replaced by pulp fibres.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    This large matrix of samples all produced successful foams, showing that our foam forming method is universal.

    “This large matrix of samples all produced successful foams, unusual given the variety of materials tested, showing that our foam forming method is universal.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Findingnone given

    All formulations were easily foamed, dried, and removed from silicone molds with appearances similar to Figure 1b.

    “All formulations were easily foamed, dried, and removed from the silicone molds with appearances similar to that shown in Figure 1b.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    A set of 15 foams with slightly different compositions all showed low density (90-130 kg m-3) and low thermal conductivity (0.0375-0.0453 W m-1 K-1).

    “A set of 15 foams with slightly different compositions described in the Experimental Section all showed a good combination of low density (90-130 kg m -3 ) and low thermal conductivity (0.0375-0.0453W m -1 K -1 ), as shown in Figure 2”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    There were no significant correlations found between thermal conductivity and microparticle dimensions or wood chemical composition, indicating foams are relatively insensitive to the type of wood feedstock.

    “There were no significant correlations found between thermal conductivity and microparticle dimensions or wood chemical composition indicating that the foams are relatively insensitive to the type of wood feedstock.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Red cedar has the largest fraction of high aspect ratio microparticles and hemlock has the largest fraction of low aspect ratio microparticles.

    “Of note, however, is that red cedar has the largest fraction of high aspect ratio microparticles and hemlock has the largest fraction of low aspect ratio microparticles.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingcitation

    PVA is ≈25 wt.% of dry foam, compared to other studies on pulp foams which either did not include PVA or included very small amounts (0.1%-0.5% concentration).

    “PVA has a large contribution to the thermal conductivity in our formulations, being ≈25 wt.% of our dry foam, compared to other studies on pulp foams which either did not include PVA [4][5][6][7][8] or included very small amounts of PVA (0.1%-0.5% concentration).[9]”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites [4]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites [5]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites [6]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims. The quote only partly states this claim.

    Findingown data

    Dry foams have a polyhedral, open-cell structure with natural honeycomb macropores and heterogeneous air bubble-templated cells (≈1100 μm).

    “The structure of the dry foams is a polyhedral, open-cell foam with natural”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Average wood microparticle length ranges from 381-490 μm and average width from 191-223 μm; longest up to 3820 μm, shortest 60 μm.

    “Table 1 shows the variety in wood microparticle sizes used: the average length ranges from 381-490 μm and the average width ranges from 191-223 μm, but the longest microparticles are up to 3820 μm while the shortest are 60 μm.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Rigid wood microparticles have a right-skewed aspect ratio distribution centered ≈2, meaning most microparticles have a short rectangular shape.

    “Figure 3a shows the wide range of aspect ratios measured and in general, our rigid wood microparticles have a right-skewed aspect ratio distribution centered ≈2, meaning that most microparticles have a short rectangular shape.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Glucopon 425 N has similar surface tension to SDS (27 mN m-1 vs 25.2 mN m-1 for SDS at 1 g L-1 at 23 °C), which likely contributes to similar properties observed in foams made with both surfactants.

    “The bio-based surfactant we selected, Glucopon 425 N, has a similar surface tension to SDS (27 mN m -1 compared to 25.2 mN m -1 for SDS, measured at 1 g L -1 at 23 °C) which likely contributes to the similar properties observed in foams made with both surfactants.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The average cell size when using TWEEN 80 was 914 μm (max: 4576 μm, min: 139 μm) and when using SDS was 1069 μm (max: 5671 μm, min: 130 μm).

    “The average cell size when using TWEEN 80 was 914 μm (max: 4576 μm, min: 139 μm) and when using SDS was 1069 μm (max: 5671 μm, min: 130 μm).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingreasoning

    Samples with a mixture of PVA and BCTMP have the lowest densities, likely related to the decreased mass of added polymer binder, which has a higher density than pulp fibres.

    “Figure 2 shows that the samples with a mixture of PVA and BCTMP have the lowest densities which is likely related to the decreased mass of added polymer binder, which has a higher density than pulp fibres.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Other formulations demonstrate successful replacement of ultrapure deionized water with simulated ocean water and SDS with bio-based surfactant Glucopon 425 N.

    “In addition to changing the wood feedstock, other formulations shown in Figure 2 demonstrate the successful replacement of ultrapure deionized water with simulated ocean water (100% PBK with ocean water) and SDS with a bio-based surfactant, Glucopon 425 N (100% PBK with Glucopon).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingnone given

    All combinations of PVA and BCTMP resulted in foams that survived the foaming and drying process and were able to be removed easily from molds.

    “All combinations of PVA and BCTMP resulted in foams that survived the foaming and drying process and were able to be removed easily from their molds.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingreasoning

    The sample with the highest cellulose content (hemlock) did not correlate to higher compressive strength, probably because it also had the largest fraction of low aspect ratio particles, nor did the sample with the highest lignin content (red cedar) correlate to lower compressive strength.

    “We found that the sample with the highest cellulose content (hemlock), did not correlate to higher compressive strength in the foams, probably because it also had the largest fraction of low aspect ratio particles, nor did the sample with the highest lignin content (red cedar) correlate to a lower compressive strength.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Shape recovery is higher for foams with a larger fraction of long fibres (BCTMP) or the highest aspect ratio microparticles (red cedar).

    “We can see that shape recovery is higher for foams with a larger fraction of long fibres (BCTMP) or the highest aspect ratio microparticles (red cedar).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    There is no positive correlation between compressive strength of bulk wood and compressive strength of foams, lending credence to the somewhat feedstock agnostic foam-forming method.

    “There is no positive correlation between the compressive strength of the bulk wood and the compressive strength of the foams, lending credence to our somewhat”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingreasoning

    Inclusion of BCTMP reduced the mass of PVA used and resulted in lighter foam frameworks that naturally led to lower thermal conductivity.

    “In this case, not only was the inclusion of BCTMP able to reduce the mass of PVA used, it also resulted in lighter foam frameworks that naturally led to having a lower thermal conductivity.”
    Quote in the paperSubstantial claim

  • May combine two claims. The quote only partly states this claim.

    Findingown data

    Addition of BCTMP increases shape recovery when compressed cyclically within the elastic region, balanced by a decrease in compressive strength.

    “However, this detriment is balanced by an increase in shape recovery with BCTMP when compressed cyclically within their elastic region, as shown schematically in Figure 5a.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingreasoning

    Red cedar has the highest compressive strength among the four wood residues tested, while hemlock had the worst.

    “Out of the four wood residues tested, red cedar has the highest compressive strength while hemlock had the worst, and we suspect this is generally correlated to the microparticle size and shape.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Thick foam boards that retained their shape through the drying step were produced in a semi-continuous fashion and were ≈1×0.5 m in size after cutting and were at least 4 cm thick.

    “Thick foam boards that retained their shape through the drying step were produced in a semi-continuous fashion and were ≈1×0.5 m in size after cutting and were at least 4 cm thick.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The full range of properties from the nine trials included a density range of 83-104 kg m -3 , a thermal conductivity range of 0.041-0.048W m -1 K -1 , and a compression strength at 10% strain range of 15-22 kPa.

    “The full range of properties from the nine trials included a density range of 83-104 kg m -3 , a thermal conductivity range of 0.041-0.048W m -1 K -1 , and a compression strength at 10% strain range of 15-22 kPa.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The cell size distributions of the pilot plant dry foams showed a right-skewed distribution, similar to the laboratory-scale foams, but overall, the pilot plant foams had smaller cells, with median values of 270-420 μm.

    “The cell size distributions of the pilot plant dry foams showed a rightskewed distribution, similar to the laboratory-scale foams shown in Figure 6c, but overall, the pilot plant foams had smaller cells, with median values of 270-420 μm (Table S1, Supporting Information).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Matching shorter microparticles with smaller air bubbles produced better foams than shorter microparticles with larger bubbles but not quite as good as longer microparticles with larger bubbles (red cedar foams with SDS).

    “Matching shorter microparticles with smaller air bubbles produced better foams than shorter microparticles with larger bubbles but not quite as good as longer microparticles with larger bubbles, i.e., red cedar foams with SDS.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingnone given

    Replacing the PVA binder with BCTMP fibres decreased foam density and thermal conductivity.

    “Replacing the PVA binder with BCTMP fibres decreased foam density and thermal conductivity, allowing us to tune the bio-based content in our foams and impart new shape recovery properties.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Three out of the nine trials yielded material properties very similar to the laboratory foams, with a density range of 89-102 kg m -3 ; a thermal conductivity range of 0.041-0.044W m -1 K -1 ; and a compression strength at 10% strain range of 17-20 kPa.

    “Three out of the nine trials yielded material properties very similar to the laboratory foams (Figure 2 and Figure 4) with a density range of 89-102 kg m -3 ; a thermal conductivity range of 0.041-0.044W m -1 K -1 ; and a compression strength at 10% strain range of 17-20 kPa.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingnone given

    All tested formulations resulted in the successful production of rigid foam boards with the ability to scale up to the pilot plant level, regardless of wood feedstock, binder, water purity, or surfactant used.

    “All tested formulations resulted in the successful production of rigid foam boards with the ability to scale up to the pilot plant level, regardless of wood feedstock, binder, water purity, or surfactant used.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Findingown data

    Minor colour differences between the foams (both pilot plant and laboratory-produced) were observed based on processing and formulation changes for scale-up, where foams with more BCTMP appeared whiter.

    “Minor colour differences between the foams (both pilot plant and laboratory-produced) were observed based on processing and formulation changes for scale-up where foams with more BCTMP appeared whiter.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable). May combine two claims.

    Premisecitation

    If feedstock from different waste streams and tree species could be used interchangeably, the method could be more widely applied and lower monetary and environmental costs for transporting materials.

    “Further, if feedstock from different waste streams and tree species could be used interchangeably, the method could be more widely applied and lower the monetary and environmental costs for transporting materials.[14]”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [14]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Probably not a substantial claim: may not pass S2 (checkable). May combine two claims.

    Premisecitation

    Using feedstock as close as possible to its natural state is a green chemistry principle and would take advantage of microstructures naturally found within the raw material.

    “Using feedstock as close as possible to its natural state is a green chemistry principle [13] and would take advantage of the microstructures naturally found within the raw material.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [13]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Costs will increase even further as fresh water becomes scarcer due to climate change.

    “Costs will increase even further as fresh water becomes scarcer due to climate change.[15]”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [15]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    While inclusion of salts is known to complicate the foam forming process, some authors have reported improved foam generation in the presence of salts.

    “While the inclusion of salts is known to complicate the foam forming process, such as changing the critical micelle concentration and surface activity of surfactants, the viscosity of the slurry and wet foam stability, some authors have reported improved foam generation in the presence of salts.[16,17]”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [16]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites [17]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Classified as probably not a substantial claim. May combine two claims.

    Premisecitation

    Wood pulp is bio-based and recyclable but requires relatively large energy input and may include hazardous side-streams.

    “Although wood pulp is a bio-based and recyclable material, it still requires a relatively large energy input and, depending on the pulping method, may include hazardous side-streams.[11]”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [11]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Premisecitation

    Pulp foams require a large amount of water for processing, with typically <2.5% pulp fibre by mass in a slurry.

    “Pulp foams are also known to require a large amount of water for processing, with typically < 2.5% pulp fibre by mass in a slurry.[12]”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [12]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Classified as probably not a substantial claim. May combine two claims.

    Interpretationown data

    The structure-property relationships elucidated offer new guidelines to optimize foam performance by matching microparticle size to bubble size, having a distribution of microparticle lengths, and preserving wood's natural macroporous character.

    “The structure-property relationships elucidated offer new guidelines to optimize foam performance by matching microparticle size to bubble size, having a distribution of microparticle lengths, and preserving wood's natural macroporous character.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim. May combine two claims.

    Premisecitation

    In past work, foams had extremely high aqueous foam stability and could tolerate a range of wood particle sizes and size distributions, with trends in thermal and mechanical properties explained by the structure of the foam cell walls.

    “In past work, we found that our foams had extremely high aqueous foam stability and could tolerate a range of wood particle sizes and size distributions, with trends in thermal and mechanical properties explained by the structure of the foam cell walls.[37]”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [37]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    We previously showed lightweight, oven-dried, high solids content foams for thermal insulation can be made from PBK wood using PVA as binder and SDS as surfactant.

    “We previously showed that lightweight, oven-dried, high solids content foams for thermal insulation can be made from pine beetle-killed (PBK) wood using polyvinyl alcohol (PVA) as the binder and sodium dodecyl sulfate (SDS) as the surfactant.[37][38][39]”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites [37]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites [38]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites [39]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Classified as probably not a substantial claim.

    Premisecitation

    Natural materials, specifically wood, have structural porosity that can act as natural thermal insulation, defined here as macroporous because the pores are larger than 0.05 μm.

    “Natural materials, specifically wood, have structural porosity (Figure 1) that can act as natural thermal insulation, which we define here as”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [23]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Classified as probably not a substantial claim.

    Premisecitation

    Effective building thermal insulation has thermal conductivities in the range of 0.01-0.1 W m-1 K-1.

    “Effective building thermal insulation has thermal conductivities in the range of 0.01-0.1 W m -1 K -1 .[18]”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [18]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Premisecitation

    The primary heat transfer mechanisms in our foams are conduction through the solid and gaseous phases and radiation, with convection considered negligible for materials with small pores/cells.

    “The primary heat transfer mechanisms in our foams are conduction through the solid and gaseous phases and radiation, with convection considered negligible for materials with small pores/cells.[55]”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [55]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Premisecitation

    Wood's thermal conductivities are 0.1-0.3 W m-1 K-1, slightly too high for typical building insulation.

    “However, their thermal conductivities are 0.1-0.3W m -1 K -1 , [24][25][26] which are slightly too high for use as typical building insulation (Figure 2).[18]”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites [24]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites [25]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites [26]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Interpretationreasoning

    Pilot plant production was only achievable because rigid wood microparticles are essentially feedstock agnostic and produce foams with similar performance to lab scale.

    “This was only achievable because, despite the variation in feedstock used, the rigid wood microparticles that dominate the process are essentially”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    PVA has historically been sourced from petrochemical resources, with only one company claiming fully bio-based PVA synthesis from sugarcane.

    “However, it has historically been sourced from petrochemical resources, [41] with only one company, to our knowledge, claiming to have a fully bio-based PVA synthesis process from sugarcane.[42]”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [41]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites [42]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Interpretationreasoning

    Pilot plant foams are thick, meter-scale boards and have the potential to replace petrochemical-based rigid boards for thermal insulation.

    “These pilot plant foams are thick, meter-scale boards, pictured in Figure 1a, and have the potential to replace petrochemical-based rigid boards for thermal insulation.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    PVA is well known for its binding ability and can act as a surfactant if its degree of hydrolysis is sufficiently high.

    “It is well known for its binding ability and can even act as a surfactant if its degree of hydrolysis is sufficiently high.[9,40]”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [9]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites [40]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Interpretationown data

    Based on information from the large data set, we elucidated the role of each foam component and developed two guidelines for foam design to expand the library of bio-based insulative foams.

    “Based on information from this large data set we were able to elucidate the role of each foam component and develop two guidelines for foam design to expand this library of bio-based insulative foams.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    This suggests a weak link between microparticle aspect ratio distribution and thermal conductivity, if density remains unchanged, and including higher aspect ratio microparticles may be an advantage for thermal insulation.

    “This suggests a weak link between microparticle aspect ratio distribution and thermal conductivity, if density remains unchanged, and including higher aspect ratio microparticles may be an advantage for thermal insulation.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    Our aqueous foaming process uses much higher solids content (>14% wood microparticles by mass) compared to pulp fibre foams (<2.5% pulp fibres by mass), meaning less water for foaming and less water to dry.

    “Our aqueous foaming process also differs because we use a much higher solids content (> 14% wood microparticles by mass) compared to pulp fibre foams (< 2.5% pulp fibres by mass), meaning we require less water for foaming and have less water to dry.[12]”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [12]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Premisecitation

    Addition of porosity to a solid polymeric material decreases thermal conductivity, with decreasing pore size corresponding to decreasing thermal conductivity.

    “It is well understood that the addition of porosity to a solid (synthetic) polymeric material decreases thermal conductivity, with decreasing pore size corresponding to decreasing thermal conductivity, [44,45]”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [44]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites [45]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Premisecitation

    The most common rigid foam board thermal insulation worldwide remains petrochemically-derived EPS and PU, which pose environmental problems due to high energy consumption (99.63-127.31 MJ eq per functional unit) compared to natural fibre insulation (19.39-59.37 MJ eq per functional unit) and low recyclability potential.

    “Despite increased attention toward more sustainability in construction, the most common rigid foam board thermal insulation worldwide remains petrochemically-derived expanded polystyrene (EPS) and polyurethane (PU), [19,20] which pose environmental problems due to their high energy consumption during manufacturing (99.63-127.31MJ eq per functional unit) compared to natural fibre insulation (19.39-”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites [19]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites [20]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites [18]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Premisecitation

    PVA has thermal conductivity 0.1-0.5 W m-1 K-1 and wood has thermal conductivity generally 0.1-0.3 W m-1 K-1 for dry softwood.

    “PVA has a thermal conductivity of 0.1-0.5 W m -1 K -1 [57,58] and wood has thermal conductivity values that vary depending on age, moisture content, and direction of heat flow relative to wood grain, but are generally 0.1-0.3W m -1 K -1 for dry softwood.[24][25][26]”
    Quote in the paperSubstantial claim0 of 4 sources checked
    • cites [57]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites [58]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites [24]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites [25]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Classified as probably not a substantial claim.

    Premisecitation

    Improving the strength-to-weight ratio of lightweight fibrillar materials may be improved by including fines, which can build material bridges between fibres.

    “Work by Pöhler et al. demonstrated that improving the strength-to-weight ratio of lightweight fibrillar materials may be improved by including fines, which can build material bridges between fibres.[9]”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [9]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Interpretationreasoning

    Heat is transferred at similar rates through the solid phase and does not distinguish between PVA and wood microparticles, explaining why thermal conductivity of foams is not greatly affected by microparticle dimensions.

    “Heat is transferred at similar rates through the solid phase and does not distinguish between the PVA and wood microparticles, explaining why the thermal conductivity of the foams is not greatly affected by microparticle dimensions.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Interpretationnone given

    The minimum strength specified by ASTM C578-22 (35 kPa) quantifies that the foams are easily handled without breaking.

    “The minimum strength specified by ASTM C578-22 (35 kPa) quantifies that the foams are easily handled without breaking.”
    Quote in the paperNot a substantial claim
    • Rests on an assumption: Building insulation does not need to be loadbearing.

  • May combine two claims.

    Interpretationreasoning

    Shape recovery performance of foams is attributed to mechanical entanglement of BCTMP fibres and PBK microparticles, and red cedar microparticles with themselves.

    “The shape recovery performance of the foams is attributed to mechanical entanglement of the BCTMP fibres and the PBK microparticles, and the red cedar microparticles with themselves.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    Mechanical failure for foams with a smaller microparticle size is likely occurring along the length of the cellular struts instead of at the hinges, resulting in lower compressive strength.

    “Mechanical failure for foams with a smaller microparticle size is likely occurring along the length of the cellular struts instead of at the hinges, resulting in lower compressive strength.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim.

    Premisecitation

    For porous, non-continuous materials, load is transferred from fibre to fibre via fibre-fibre joints or connecting resins.

    “Pöhler et al. comments that for porous, non-continuous materials, load is transferred from fibre to fibre via fibre-fibre joints or connecting resins.[6]”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [6]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Classified as probably not a substantial claim.

    Interpretationreasoning

    The difference in compressive strength among wood residues is generally correlated to microparticle size and shape.

    “Out of the four wood residues tested, red cedar has the highest compressive strength while hemlock had the worst, and we suspect this is generally correlated to the microparticle size and shape.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S4 (based). May combine two claims.

    Interpretationreasoning

    Since PVA connects the solid structure, there is minimal contact resistance between rigid wood microparticles, and solid conductivities are very similar when foam densities are the same.

    “Since PVA connects the solid structure in our foams, there is minimal contact resistance between rigid wood microparticles, and solid conductivities are very similar when foam densities are the same.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Interpretationown data

    Samples that exceeded compressive strength were all made from wood on the higher end of microparticle aspect ratio (PBK and red cedar high vs SPF and hemlock low), suggesting a relationship between higher aspect ratio microparticles and increased compressive strength.

    “These samples were all made from wood on the higher end of microparticle aspect ratio (PBK and red cedar are high versus SPF and hemlock that are low), suggesting a relationship between higher aspect ratio microparticles and increased compressive strength.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Other bio-based materials vary: ≈2-50 kPa for cellulose nanofibril foams, ≈220 kPa for TEMPO-oxidized wood xerogels, and 17-111 kPa for pulp-chitosan foams.

    “Other bio-based materials vary, for example ≈2-50 kPa for cellulose nanofibril foams, [63] ≈220 kPa for TEMPOoxidized wood xerogels, [64] and 17-111 kPa for pulp-chitosan foams.[65]”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites [63]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites [64]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites [65]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Interpretationcitation

    This is attributed to overlapping thermal conductivity values for the three components, suggesting bulk wood conductivity is more sensitive to microstructure than composition.

    “This is attributed to the overlapping thermal conductivity values for the three components [60][61][62] suggesting that bulk wood conductivity is more sensitive to microstructure than composition.”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites [60]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites [61]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites [62]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Classified as probably not a substantial claim.

    Interpretationreasoning

    The concept of load transfer via fibre-fibre joints or connecting resins can be applied to rigid particles as well.

    “Although this comment was referring to pulp-based foams, this concept is wellknown in mechanics and can be applied to rigid particles as well.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    While aqueous bubble size may not have been a predictor for final properties such as thermal conductivity and compressive strength when using flexible microparticles/fibres, it appears to be correlated for rigid microparticles as shown by our improved thermal conductivity and compressive strength in the TWEEN 80 sample.

    “While aqueous bubble size may not have been a predictor for final properties such as thermal conductivity and compressive strength when using flexible microparticles/fibres, it appears to be correlated for rigid microparticles as shown by our improved thermal conductivity and compressive strength in the TWEEN 80 sample.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing).

    Interpretationreasoning

    Using TWEEN 80 with smaller bubbles as the surfactant instead of SDS may offer better results for pilot plant foams.

    “Also, as cell sizes were smaller than observed during the laboratory-phase, using TWEEN 80 with smaller bubbles as the surfactant instead of SDS may offer better results.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationreasoning

    Since our foams use naturally imperfect wood feedstocks, minimally processed microparticles, and uncontrolled deposition of microparticles during foam laying, there will always be a range of microparticle sizes and shapes and polyhedral cell sizes and only an approximate match is feasible.

    “This guideline is balanced by the first one: since our foams use naturally imperfect wood feedstocks, minimally processed microparticles, and uncontrolled deposition of microparticles during foam laying, there will always be a range of microparticle sizes and shapes and polyhedral cell sizes and only an approximate match is feasible.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim.

    Premisecitation

    Relatively stiff chemi-thermo-mechanical pulp (CTMP) fibres strongly influence the dry cell size compared to flexible Kraft fibres.

    “Past work by Al-Qararah et al. alluded to a similar mechanism whereby relatively stiff chemi-thermo-mechanical pulp (CTMP) fibres strongly influence the dry cell size compared to flexible Kraft fibres.[70]”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [70]

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Probably not a substantial claim: may not pass S2 (checkable).

    Interpretationreasoning

    The versatility of our method, and the use of minimally processed, naturally microporous, rigid microparticles, has allowed us to develop a platform for the design of future variations in bio-based foams.

    “The versatility of our method, and the use of minimally processed, naturally microporous, rigid microparticles, has allowed us to develop a platform for the design of future variations in bio-based foams.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductnone given

    Tests were performed on five specimens per sample, with one 50:50 BCTMP:PVA (PBK) sample result discarded due to failure along an obvious flaw.

    “Tests were performed on five specimens per sample, with one 50:50 BCTMP:PVA (PBK) sample result discarded due to failure along an obvious flaw.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationreasoning

    Carefully selecting the bubble size to match average microparticle size, or vice versa, may yield lower thermal conductivity and increased compressive strength.

    “This suggests that carefully selecting the bubble size to match average microparticle size, or vice versa, may yield lower thermal conductivity and increased compressive strength.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationcitation

    Flexible fibres conform to bubbles and spaces around them may collapse during the drying step, whereas rigid fibres or microparticles are more able to impose and keep structure around the bubbles.

    “This is because flexible fibres conform to bubbles and spaces around them may collapse during the drying step, whereas rigid fibres or microparticles are more able to impose and keep structure around the bubbles.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    The best compressive strengths can be achieved when a polyhedral cell edge approximately matches the length of one microparticle, because the compressive failure mode will occur at cell hinges instead of along the cell strut.

    “The best compressive strengths can be achieved when a polyhedral cell edge approximately matches the length of one microparticle, because the compressive failure mode will occur at cell hinges instead of along the cell strut.”
    Quote in the paperNot a substantial claim
76 of 76

  • The paper relies on this without support.

    Building insulation does not need to be loadbearing.

    “However, building insulation does not need to be loadbearing.”

  • The authors state this as an assumption.

    The law of mixtures applies to 50:50 blends of wood species for estimating compressive strength.

    “and 50:50 blends assuming the law of mixtures”

  • The paper relies on this without support.

    BCTMP is a low cost, minimally-processed wood pulp.

    “i.e., a low cost, minimally-processed wood pulp”

  • The paper relies on this without support.

    Rigid wood microparticles are stiffer and resist higher loads with lower strain than flexible fibres.

    “Rigid wood microparticles are stiffer and resist higher loads with lower strain than flexible fibres”

  • The paper relies on this without support.

    PVA is biodegradable and compatible with lignocellulosic materials.

    “it is a well-characterized material that is biodegradable and compatible with lignocellulosic materials.”

  • The paper relies on this without support.

    Glucopon 425 N is a bio-based surfactant.

    “SDS with a bio-based surfactant, Glucopon 425 N”

  • The paper relies on this without support.

    Microparticles or fibres/fines produced from milling represent only a small fraction of the total material produced.

    “Conversely, microparticles or fibres/fines produced from milling represent only a small fraction of the total material produced.”

  • The paper relies on this without support.

    Our microparticles are more rigid than CTMP fibres.

    “Since our microparticles are more rigid than CTMP fibres, the link between bubble size and final properties may be just as strong.”

  • The paper relies on this without support.

    A cell radius of 457 μm corresponds to a pentagon side length of 664 μm or an octagon side length of 379 μm.

    “A cell radius of 457 μm (i.e., half the average TWEEN 80 cell size) corresponds to a pentagon side length of 664 μm or an octagon side length of 379 μm, whereby the octagon side length is closest to the average hemlock microparticle size of 381 μm.”
9 of 9

Statistics recomputed

Every reported test result, recomputed from its test statistic and degrees of freedom. A result shows as not adding up only once an independent check has confirmed it.

  • ConsistentF(4, 22) = 3.4reported p < .03 · recomputed p = .026

    “F(4,22) = 3.4, p < .03”

1 of 1

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Self-check results appear here once an independent check has confirmed them.

Cites

Flagged first, then by citations

Research works printed but not linked: 6

  1. 2014, The IUPAC Compendium of Chemical Terminology, International Union of Pure and Applied Chemistry (IUPAC)
  2. Nagarkar R., 2019, Acta Sci. Pharmaceu. Sci., 3, 34
  3. News R. C., 2022, Bioplastics International
  4. P.Cooper P.Morris inCanadian Wood Preservation Association (CWPA)2007 pp.9.
  5. Bisson J., 2016, Am. J. Biomass Bioener.
  6. Li L., 2021, Comp. Commun., 23

Cited by

Sorted by citations

Related

Authors
Dobrzanski, E., Schnell, J., Zhang, W., Ferreira, E. S., Keränen, J., Agrawal, P., Yuan, Y., Chen, R., Tiwary, P., & Cranston, E. D.
Affiliations
  • University of British Columbia (CA)
  • Technical University of Munich (DE)
  • VTT Technical Research Centre of Finland (FI)
  • Plantee Bioplastics Inc. Vancouver BC V6G 3J9 Canada
Corresponding author
Cranston, Emily D.
ORCID
Venue
Advanced Sustainable Systems
Publisher
Wiley
Published
2025-04-21
Volume
9
Issue
6
ISSN
2366-7486 (ISSN-L)
DOI
10.1002/adsu.202400986
OpenAlex
W4409649483
Semantic Scholar
7d02fcb8b5e9f6a3627ac206798de149e289da04
Cited by
1
References
57
Citations by year
2026: 1
FWCI
0.23
Type
journal article
Language
en
Open access
Licence
Locations
Advanced Sustainable Systems (publishedVersion, cc-by-nc-nd)
Funders
  • Natural Sciences and Engineering Research Council of Canada (RGPIN‐2018‐06818)
  • Mitacs (IT22973, IT30768, IT37506)
Topics
  • Physical Sciences › Materials Science › Polymers and Plastics › Polymer Foaming and Composites
  • Physical Sciences › Engineering › Building and Construction › Hygrothermal properties of building materials
  • Physical Sciences › Materials Science › Polymers and Plastics › Natural Fiber Reinforced Composites
Keywords
rigid foam insulation, wood waste, mechanical pulp, biosurfactants, thermal conductivity, low-density foam, structure-property relationships, microparticle size, bio-based insulation

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-22.

Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-22.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

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