Characterization of polyurethane foams from soybean oil

Abstract

Modified soy-based vegetable oil polyols were successfully incorporated as a replacement for conventional polyols to produce flexible slabstock polyurethane foams. The oil was characterized for its hydroxyl value and fatty acid composition. The modified oils had higher hydroxyl values and lower unsaturated acids than regular unmodified oils. Three different modified polyols were used to investigate the reactivity with isocyanates. The effects on the foaming reaction of two different isocyanates, namely TDI and MDI, were investigated. The reactions were also carried out with a mixture of polyols containing synthetic polyols and vegetable oil-based polyols to delineate the effect of each component. FTIR technique was used to identify the sequence of chemical reactions during the foaming process. The effect of water levels and isocyanate content on the kinetics of the foaming reaction was investigated. Information regarding the formation of hard and soft segments with the varying compositions was obtained. As the water content increased, the amount of the hard segment and urea formation increased in both soy oil polyols and synthetic polyols. Increased synthetic polyols in the mixture increased the rate of reaction and phase mixing due to the availability of primary hydroxyl groups. Scanning electron microscopy (SEM) and small-angle X-ray scattering (SAXS) were used to probe the morphology. As the water content increased, the cell size increased. At lower water content a more uniform cell structure was evident and at higher water levels hard domain size increased.

Polyurethanes from tung oil: Polymer characterization and composites

“…This value is clearly higher than the theoretically calculated value (M n ¼ 875.4 g/mol) and also than the value calculated from the saponification acid numbers assuming that the oil is monodisperse (M n ¼ 914.4 g/mol). John et al [12] have previously reported a large aberration in the SEC characterization of triglycerides. They worked with soy oil and although the polydispersity of the samples was very low (M w /M n ¼ 1.01), as it is the case in this work, the molar masses determined by this method almost doubled the actual masses of the triglycerides.…”

Microwave-Assisted Synthesis of Polyols from Rapeseed Oil and Properties of Flexible Polyurethane Foams

“…Vegetable oil-based polyols derived from oil seeds, such as sunflower, soybean, canola and rapeseed, were applied in PUR flexible foams synthesis [4,9,13,14]. These modifications had limited success and showed that partial incorporation of vegetable oil-based polyols is much more successful.…”

Synthesis and Evaluation of New Anti-microbial Additives Based on Pyrazole and Triazole Derivatives Incorporated Physically into Polyurethane Varnish for Surface Coating and into Printing Ink Paste

“…Polyurethanes are an important and very versatile class of polymer materials with desirable properties, such as high abrasion resistance, tears strength, excellent shock absorption, flexibility and elasticity (20)(21)(22) . The attractiveness of polyurethanes stems from their excellent bonding to different substrates, relatively low price and fast reaction time (23) .…”