DEVELOPMENT OF POLYURETHANE COMPOSITIONS BASED ON THE LINEAR POLYMER WITH THE END OF ISOCYANATE GROUPS
Polyurethane elastomers find wide practical application in various fields of industry, agriculture and everyday life, thanks to a set of valuable properties. Time to get one finished product made of polyurethane is several times longer than the time it takes to manufacture rubber parts. In this regard, the work devoted to the development of polyurethane polymer composite materials with accelerated curing time is relevant and expedient. Polyurethane compositions based on Adipren-L 100 and Adipren-L 167 rubbers differing in the different hardener content (12.0 parts by weight and 19.0 parts by weight of hardener per 100 parts by weight of urethane rubber, respectively) catalyst - adipic acid, their physical and mechanical properties are studied. It has been established that a sample containing a hardener in a larger quantity has higher physico-mechanical properties. This is probably due to the elongation of the polymer chain, an aromatic amine-based hardener is able to regulate the degree of cross-linking or branching of chains in the final vulcanizate. In addition, studies have shown that the use of adipic acid, as a catalyst in an amount of 0.3 parts by weight per 100 parts by weight polymer makes it possible to shorten the time before extraction of the casting from the mold by 2.2-2.9 times, while the lifetime of the polyurethane composition is reduced by 2-3 times, the curing time of the product at 100°C is reduced by 3.75-4 times depending on the brand Adipren-L. The physical and mechanical tests of a polymer composition based on Adipren-L of various grades using an adipic acid catalyst, showed that the hardness is 91 to 94 units Shore A; tear resistance - 21.2-24.1 N/mm. Based on the obtained results of the study, it can be concluded that the introduction of adipic acid into the polyurethane composition makes it possible to improve the complex of physico-mechanical and operational properties.