Study On Synthesis And Modification Of Polyester Polyurethane

Polyurethane(PU) with high abrasion resistance, tear resistance and resistance to flexible, and therefore is widely used in various fields such as building materials, chemical products, light industry and so on. It is a booming macromolecule material. Polysiloxane has unique molecules and exhibit unique properties, such as high intensity ultraviolet resistance, electrical insulation, acid and alkali corrosion resistance, hydrolysis resistance,resistance to ozone aging and physiological inertia etc. It is a kind of effective method that polyurethane modified by polysiloxane to improve the weatherability, thus driving people’s attention and recognition and expanding the application scope of polyurethane.In this study, polyester polyurethane block copolymer was synthesized with3-Isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate(IPDI), poly caprolactone glycol(PCL) and 1,4-butanediol(BDO) as chain extenders. Results from FTIR、TGA、Viscosity test and Mechanics performance test suggested that the polyurethane heat resistance increased gradually with hard segment content increasing. When soft segment :hard segment is 1:5, polyurethane has good liquidity and shows good mechanical properties. Therefore, in this experiment the soft hard segment with a ratio of 1:5 was determined. In this condition, polyurethane elastomer comprehensive performance is the best. Exposure experiment of the PU samples was implemented in self-made artificial accelerated ageing equipment. Color difference and the yellow index analysis results showed that with increasing of hard segment content, the resistance of polyurethane elastomer degeneration gradually improved.In order to improve the performance of polyurethane, the modified polyester polyurethane was synthesized by polydimethylsioxane(PDMS) and the influence of different silicone content on the performance of polyurethane was studied. The results from FTIR、TGA、Viscosity test and Mechanics performance test suggested that organic silicon chain successful embedded in polyurethane chain segment, and with the increase of the content of organic silicon, heat resistance of polyurethane elastomer gradually strengthened; When the organic silicon content was 18%, mechanical properties achievedoptimal performance. Aging test results showed that the organic silicon embedded made the weatherability of polyurethane improved.