초록 |
Due to the outstanding physical properties, polyurethanes (PU) have been widely used in the various fields for coating, fiber, insulation, cushioning, and adhesives. Usually, the PU elastomers are synthesized by the reaction of isocyanate (N=C=O) terminated PU prepolymers and cross linking agent. In the application of PU system, moisture sensitivity of isocyanates is one of difficulities due to the high reacticity of N=C=O with moisture, resulting in undesirable product through the irreversible urea forming side reaction. And storage stability of PU prepolymers also could be negatively affected by moisture in the environments. To overcome these drawbacks of conventional PU systems, non-isocyante PU (NIPU) system based on the end-capping of PU prepolymers with glycerol carbonate (GC) and curing by the reaction of cyclic carbonate and amine was investigated. The capping of N=C=O groups with GC alleviated the moisture sensitivity and improved the storage stabilities of PU systems. |