Polyurethane Foams from the Reaction of Bark and Diisocyanate

Hartman, Seymour

doi:10.1021/bk-1977-0043.ch016

Cited by 5 publications

(7 citation statements)

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“…Oak bark had been used as a resource to extract tannins for polyphenolics in preparation of exterior adhesives or antioxidants . Owing to the abundant hydroxyl groups from polyphenolics and polysaccharides in the bark, Hartman et al directly used bark powder as a heterogeneous polyol to react with highly active isocyanate compounds to produce PU foam . Creatively, D’Souza and Yan obtained liquefied bark by using polyethylene glycol and glycerol as solvent and water/xylene as cosolvent, with sulfuric acid as catalyst, to extract the aromatic compounds .…”

Section: Introductionmentioning

confidence: 99%

“…10 Owing to the abundant hydroxyl groups from polyphenolics and polysaccharides in the bark, Hartman et al directly used bark powder as a heterogeneous polyol to react with highly active isocyanate compounds to produce PU foam. 11 Creatively, D'Souza and Yan obtained liquefied bark by using polyethylene glycol and glycerol as solvent and water/xylene as cosolvent, with sulfuric acid as catalyst, to extract the aromatic compounds. 12 These liquified bark compounds were further used directly as polyols to make polyurethane foams.…”

Section: ■ Introductionmentioning

confidence: 99%

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Valorization of Bark Using Ethanol–Water Organosolv Treatment: Isolation and Characterization of Crude Lignin

Liu

Patankar

Chandra

et al. 2020

ACS Sustainable Chem. Eng.

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Bark serves multiple functions for a tree by combining protection and fluid transport. The tissue itself is composed of multiple types of material that includes typical cell wall structural polymers of cellulose and lignin, as well as extractives. With suitable fractionation, these bark constituents may serve to help valorize biomass when converted into feedstocks for polymeric precursors, such as aromatic polyols. In this study, organosolv processing was used to solubilize around 50% of pine bark (PB) and oak bark (OB), followed by the recovery of around 20% crude lignin. Two-dimensional 1 H− 13 C heteronuclear single quantum coherence (2D HSQC) NMR and 13 C NMR revealed the crude lignin also contained mixed polyphenolics, suberin-compounds, and carbohydrate compounds, especially for PB. To optimize the extraction process, a two-level factorial design was used to study the impacts of temperature, ethanol concentration, and solid loading on the yield and related characteristics of crude lignin. Increased temperature and ethanol concentration during processing allowed more solubilization of the components along with the extraction of crude lignin with higher yield. The correlation analysis found that the thermal stability of crude lignin had a direct relationship with aromatic hydroxyl group content, while the glass transition temperature was impacted by the lower molar mass components contained in the crude lignin. Overall, the study showed promise to solubilize a high portion of bark material and provided insight into structure−property relationships of crude lignin-derived from an important, yet underutilized resource as a function of processing conditions.

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Section: Introductionmentioning

confidence: 99%

Section: ■ Introductionmentioning

confidence: 99%

Valorization of Bark Using Ethanol–Water Organosolv Treatment: Isolation and Characterization of Crude Lignin

Liu

Patankar

Chandra

et al. 2020

ACS Sustainable Chem. Eng.

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“…Bark is a renewable biomass that has demonstrated large potential as a raw material for synthesizing phenol-formaldehyde adhesives (Zhao et al, 2013) and bio-based polyols for making polyurethanes foams (PUFs) (Ge and Sakai, 1993;Hartman, 1977;Ueno, 2007;Zhao et al, 2011). PUFs are known most notably for their versatility that enables their use in a variety of applications, including cushioning and sound absorption in the automotive industry and as insulation in appliances, homes, and commercial buildings.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and characterization of bio-polyols through the oxypropylation of bark and alkaline extracts of bark

D’Souza

George

Camargo

et al. 2015

Industrial Crops and Products

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“…Bark is a renewable biomass that has demonstrated a large potential as a raw material for synthesizing biobased phenol-formaldehyde adhesives and polyols for making polyurethanes foams (PUFs). − PUFs are known most notably for their versatility that enables their use in a variety of applications including cushioning and sound absorption in the automotive industry and as insulation in appliances, homes, and commercial buildings. PUFs are synthesized through an addition reaction of an isocyanate with an active hydrogen group, typically a hydroxyl or water.…”

Section: Introductionmentioning

confidence: 99%

Solvolytic Liquefaction of Bark: Understanding the Role of Polyhydric Alcohols and Organic Solvents on Polyol Characteristics

D’Souza

Wong

Camargo

et al. 2015

ACS Sustainable Chem. Eng.

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Bark was liquefied in polyhydric alcohols of various functionality, equivalent weight, and hydroxyl type, and organic solvents of varying polarity to determine how these features impact liquefaction behavior and polyol characteristics. It was found that the liquefaction yield was highly tunable with the use of polyhydric alcohols with primary hydroxyl groups, with low equivalent weight alcohols providing the highest liquefaction yield (59.3%). This showed that the highly polar hydroxyls (primary) and short chains created a highly protic solvent that improved conversion and protected the biopolymers from degradation. This was corroborated by 1 H NMR analysis that indicated a greater amount of sugar degradation products were observed when polyhydric alcohols with secondary hydroxyl groups were used. Regarding organic solvents, ketonic solvents showed the greatest increase in the liquefaction yield. The composition and carbon content analysis of the residues suggested that the highly polar carbonyl group of ketonic solvents like acetyl acetone and cyclohexanone may have hindered condensation side reactions. These results have shown that selection of polyhydric alcohols and organic cosolvents can be quite impactful on the liquefaction yield and the polyol characteristics.

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Polyurethane Foams from the Reaction of Bark and Diisocyanate

Cited by 5 publications

References 0 publications

Valorization of Bark Using Ethanol–Water Organosolv Treatment: Isolation and Characterization of Crude Lignin

Valorization of Bark Using Ethanol–Water Organosolv Treatment: Isolation and Characterization of Crude Lignin

Synthesis and characterization of bio-polyols through the oxypropylation of bark and alkaline extracts of bark

Solvolytic Liquefaction of Bark: Understanding the Role of Polyhydric Alcohols and Organic Solvents on Polyol Characteristics

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