Andrew Guo

Polyurethane networks from polyols obtained by hydroformylation of soybean oil

Polymer International, 2008

BACKGROUND: Vegetable oil-based polyols are a new class of renewable materials. The structure of ... more BACKGROUND: Vegetable oil-based polyols are a new class of renewable materials. The structure of oil-based polyols is very different from that of petrochemical polyols, and it is closely related to the structure of oils. The objective of this work was to analyze the structural heterogeneity of soy-based polyols and its effect on the properties of polyols and polyurethanes.RESULTS: A series of polyols with a range of hydroxyl numbers were prepared by hydroformylation and partial esterification of hydroxyls with formic acid. Polyols were reacted with diphenylmethane diisocyanate to obtain polyurethanes of different crosslinking density. Gelation was simulated using the Monte Carlo method with a calculated distribution of functionalities for each polyol.CONCLUSIONS: Most polyols are powerful crosslinkers since weight average functionality varied from 5 to 2.5 resulting in gel points from 53 to 83% conversion. Heterogeneity of polyols had a negative effect on mechanical properties of rubbery polyurethanes and this should be taken in account when designing polyols for flexible applications. This effect was not pronounced in glassy polyurethanes. Copyright © 2007 Society of Chemical Industry

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Rigid polyurethane foams based on soybean oil

Journal of Applied Polymer Science, 2000

Both HCFC-and pentane-blown rigid polyurethane foams have been prepared from polyols derived from... more Both HCFC-and pentane-blown rigid polyurethane foams have been prepared from polyols derived from soybean oil. The effect of formulation variables on foam properties was studied by altering the types and amounts of catalyst, surfactant, water, crosslinker, blowing agent, and isocyanate, respectively. While compressive strength of the soy foams is optimal at 2 pph of surfactant B-8404, it increases with increasing the amount of water, glycerin, and isocyanate. It also increases linearly with foam density. These foams were found to have comparable mechanical and thermoinsulating properties to foams of petrochemical origin. A comparison in the thermal and thermooxidative behaviors of soy-and PPO-based foams revealed that the former is more stable toward both thermal degradation and thermal oxidation. The lack of ether linkages in the soy-based rather than in PPO-based polyols is thought to be the origin of improved thermal and thermo-oxidative stabilities of soy-based foams.

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Polyols and Polyurethanes from Hydroformylation of Soybean Oil

Journal of Polymers and The Environment, 2002

This paper compares physical and mechanical properties of polyurethanes derived via the hydroform... more This paper compares physical and mechanical properties of polyurethanes derived via the hydroformylation approach and is a part of our study on the structure–property relationships in polyurethanes created from vegetable oils. The double bonds of soybean oil are first converted to aldehydes through hydroformylation using either rhodium or cobalt as the catalyst. The aldehydes are hydrogenated by Raney nickel to alcohols, forming a triglyceride polyol. The latter is reacted with polymeric MDI to yield the polyurethane. Depending on the degree of conversion, the materials can behave as hard rubbers or rigid plastics. The rhodium-catalyzed reaction afforded a polyol with a 95% conversion, giving rise to a rigid polyurethane, while the cobalt-catalyzed reaction gives a polyol with a 67% conversion, leading to a hard rubber having lower mechanical strengths. Addition of glycerine as a cross-linker systematically improves the properties of the polyurethanes. The polyols are characterized by DSC. The measured properties of polyurethanes include glass transition temperatures, tensile strengths, flexural moduli, and impact strengths.

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The study of oxazolidone formation from 9,10-epoxyoctadecane and phenylisocyanate

Journal of The American Oil Chemists Society, 2003

The formation of oxazolidone from 9,10-epoxyoctadecane and phenylisocyanate was studied. One bran... more The formation of oxazolidone from 9,10-epoxyoctadecane and phenylisocyanate was studied. One branch of epoxidized vegetable oil with one epoxy group per chain corresponds to 9,10-epoxyoctadecane. This model could explain the probability of oxazolidone formation from natural oil-derived epoxides. Epoxidized natural oils are TG consisting of glycerin and three FA with or without one to three epoxy groups in the middle of the chain. To study oxazolidone formation from an internal epoxy group without possible interference from the side reactions on the ester group, 9,10-epoxyoctadecane was selected as the most appropriate model compound. Epoxy groups in the middle of allong aliphatic chain are of low reactivity toward isocyanates, and preparation of oxazolidones requires fairly harsh conditions such as high temperatures and catalysts, which also promote side reactions. The dominant side reaction is rearrangement of the epoxy groups. We found that the direction and magnitude of the rearrangement and the yield of any particular product depended on the catalyst used. Lithium chloride, aluminum trichloride, and zinc iodide catalyzed oxazolidone formation, along with the catalysis of side reactions such as ketone and carbonate formation. Aluminum trichloride showed the highest conversion of 9,10-epoxyoctadecane to oxazolidone. Aluminum triisopropoxide, triphenylantimony iodide, and imidazole did not catalyze the formation of oxazolidone. They were effective as catalysts of epoxy group rearrangement and promoted the formation of hydroxyl, ketone, and carbonate compounds. Hydroxyl groups reacted with isocyanate to produce urethane.

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Rigid polyurethane foams based on soybean oil

Journal of Applied Polymer Science, 2000

Both HCFC-and pentane-blown rigid polyurethane foams have been prepared from polyols derived from... more Both HCFC-and pentane-blown rigid polyurethane foams have been prepared from polyols derived from soybean oil. The effect of formulation variables on foam properties was studied by altering the types and amounts of catalyst, surfactant, water, crosslinker, blowing agent, and isocyanate, respectively. While compressive strength of the soy foams is optimal at 2 pph of surfactant B-8404, it increases with increasing the amount of water, glycerin, and isocyanate. It also increases linearly with foam density. These foams were found to have comparable mechanical and thermoinsulating properties to foams of petrochemical origin. A comparison in the thermal and thermooxidative behaviors of soy-and PPO-based foams revealed that the former is more stable toward both thermal degradation and thermal oxidation. The lack of ether linkages in the soy-based rather than in PPO-based polyols is thought to be the origin of improved thermal and thermo-oxidative stabilities of soy-based foams.

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Structure–property relationships in polyurethanes derived from soybean oil

Journal of Materials Science, 2006

Two types of soy polyols have been prepared, one with secondary OH groups resulted from epoxidati... more Two types of soy polyols have been prepared, one with secondary OH groups resulted from epoxidation of soybean oil followed by methanolysis (polyol type I) and the other with primary OH groups created from hydroformylation of soybean oil followed by hydrogenation (polyol type II). Cast polyurethane resins were prepared from these two types of polyols with Isonate 2143L, and rigid polyurethane foams were prepared from a blend of soy polyol and glycerol with PAPI 2901. Polyol II is much more reactive than polyol I towards polyurethane formation. This is evidenced from studies on polyurethane gel-times, glass transitions and rigid foam mechanical strengths. The reaction for the polyurethane formation is more complete for polyol II resulted from its higher reactivity than polyol I, although a less rigid polyurethane material is resulted from polyol II than from polyol I. Polyol type II also requires lower amounts of catalysts for rigid foam formulation. Both rigid foam systems produce foams having the required mechanical strength. The polyol II foam system behaves much like conventional rigid foam systems where the strength are proportional to system OH content, while the less reactive polyol I system does not.

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Laminates From The Soy-Based Polyurethanes and Natural and Synthetic Fibers

Two polyols were prepared from soybean oil, one by epoxidation route and the other via hydroformy... more Two polyols were prepared from soybean oil, one by epoxidation route and the other via hydroformylation. The polyol obtained by epoxidation has secondary groups and has a gel time of more than one hour when reacted with crude MDI to produce polyurethanes. Hydroformylated polyol has a gel time with MDI of several minutes and is more suitable for reinforced reaction

Structure and properties of polyurethanes based on halogenated and nonhalogenated soy-polyols

Journal of Polymer Science Part A-polymer Chemistry, 2000

Polyurethanes prepared from vegetable oils have a number of excellent properties derived from the... more

Structure and properties of halogenated and nonhalogenated soy-based polyols

Journal of Polymer Science Part A-polymer Chemistry, 2000

The preparation of polymers from renewable resources is of significant economic and scientific im... more

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