Network structure and properties of polyurethanes from soybean oil

Abstract

Vegetable oils are very heterogeneous materials with a wide distribution of triacylglycerol structures and double-bond contents. The hydrogenation of epoxidized soybean oil (ESO) produces polyols having a functionality distribution related to that of soybean oil. Therefore, these polyols are convenient substances for studying the impact of structural heterogeneity on network formation and properties. Polyols of hydroxyl numbers ranging from 225 to 82 mg KOH/g and weight-average functionalities ranging from 4.4 to 2.7 were obtained by the variation of the time of hydrogenation of ESO. An analysis of the functionality distribution in polyols shows that gel points with diisocyanates vary from 54 to 76% conversion. The molecular weights of the network chains of polyurethanes prepared from these polyols and diphenyl methane diisocyanate varied from 688 to 1993. Polyols with hydroxyl numbers above 200 mg KOH/g gave glassy polymers, whereas those below that value gave rubbers. The heterogeneity of polyols had a negative effect on the elastic properties only at low crosslinking densities.

Quaternized lignin-based dye dispersant: Characterization and performance research

“…Depending on the type of decomposition mechanism, the resulting degradation products may include alcohols, amines, olefins, carbon dioxide, and fatty acid chain scission. [25][26][27][28] The temperature at the maximum degradation rate of the alkali lignin is 267°C, while the temperature of the maximum degradation rate of QLD is 300°C. Comparing alkali lignin with QLD shows that the thermostability of QLD prevailed over alkali lignin.…”

Influence of Palm Oil-Based Polyol on the Properties of Flexible Polyurethane Foams

“…Moreover, life cycle assessment of vegetable oil polyols shows environmental benefits like reduction in the demand of fossil resources and formation of very low greenhouse gas emission [4]. Therefore, the hydroxylated derivatives of vegetable oils are interesting and alternative replacements for petrochemical polyols in the synthesis of PUR materials [5][6][7][8][9].…”

“…Analysis of the content of unsaturated bonds in various oils confirmed that palm oil is a convenient raw material for the synthesis of the polyols with low and medium content of hydroxyl groups [16]. Low content of unsaturated bonds (LI = 50-55) in palm oils allows to obtain (using the epoxidation method followed by ring opening) the products with hydroxyl numbers lower than 200 mg KOH/g and very low content of unreacted double bonds [7]. Additionally, palm oil is the cheapest among the ones currently produced vegetable oils and had the largest contribution of the total production in 2010.…”

Polymers From Biological Oils

“…The polyols discussed so far are of relatively low molar mass (~1000) and hydroxyl equivalent (200-300), suitable for rigid and semi-rigid applications (rigid foams, cast resins, coatings and adhesives). Another issue with these polyols is a wide functionality distribution ranging from 1 to 8 OH groups per molecule [19].…”