Polyols, Isocyanates, and Chain Extenders Based on Natural Sources

2 Polyols, Isocyanates, and Chain Extenders Based on Natural Sources 

Vegetable oils are an excellent renewable source of raw materials for the manufacture of polyurethane components, such as polyols hence, the chemical modification or the transformation of the double bonds of triglycerides of oils to hydroxyl moieties and their applications in polyurethanes has been the subject of many studies. The main technological advantages of these polyurethanes from vegetable oils are their high strength and 

Castor oil is a clear [almost colorless), or pale yellow-colored viscous oil, where 90% of the content corresponds to rlclnolelc acid. It presents aliphatic carboxylic acid with an 18-carbon chain, having a double bond between carbon 9 and 10 and a hydroxyl group on the carbon 12, which is exclusive to castor oil. This renewable resource also has high water resistance and, when 

Not only can polyurethane-based polyol natural sources be used in medical and chemical industries, but recently the remarkable mechanical, thermal, and morphological properties of bio-based polyurethane have made their applications widespread. 

Castor oil has been extensively used as a polyol precursor in polyurethane synthesis because of the reactive hydroxyl functional groups [OH) contained in its molecule, but polyurethanes derived from hydroxylated epoxides of linseed, soybean, and rapeseed oils have also been reported. Soybean oil is another remarkable triglyceride rich in unsaturated fatty acids that are susceptible to chemical modification for desired polymeric materials. In comparison with castor oil, soybean oil also requires strategies to functionalize them. Lubguban et al. proposed the acylglycerol 

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