Research Progress in Plant Oil-based Non-isocyanate Polyurethane

Non-isocyanate polyurethane(NIPU) can be prepared by polyaddition of cyclic carbonates and amine groups. This reaction is the best way to synthesize NIPU, which not only does not require phosgene, but also has mild reaction conditions as well as not easy to produce by-products. Starting from vegetable oil as the basic chemical raw material, the article analyzes the status and technical difficulties of conversion of plant oil-based cyclic carbonate, i.e., the raw material of plant oil-based NIPU preparation route. For example, in the synthesis of plant oil-based cyclic carbonates, although the catalytic efficiency of small-molecule homogeneous catalysts represented by tetrabutylammonium bromide is average, this type of small-molecule homogeneous catalysts is the most commonly used catalysts for practical application and research in the preparation of plant oil-based cyclic carbonates. The article describes the preparation conditions and their characteristics of five common plant oils, such as soybean oil, linseed oil, sunflower oil, castor oil and jatropha oil, for the preparation of plant oil-based NIPU, and concludes that the properties of NIPU materials obtained from different kinds of plant oils are different because of their different functionalities. Of those, soybean oil is the most reported and easier to industrialize plant oil by far. The article also summarizes the current status of vegetable oil-based NIPU applications in coatings, adhesives, foams and wound dressings.