Synthesis, Structure And Properties Of The Graft-polymer Of Poly (Styrene-alt-maleic Anhydride) And Polyurethane

The alternating copolymer of styrene and maleic anhydride (SMA) was prepared by solvent polymerization and its structure was analyzed. The polyurethane (PU) prepolymer was synthesized based on diphenylmethane 4,4 - diisocyanate (MDI) and polyether and polyester diols with various chain length, and then the PU prepolymer was grafted onto the SMA, the graft-polymer was gained. At the same time, this article studied the reactive blending between the SMA and PU, and a series of SMA/PU blends were synthesized. The structure and thermal properties of the graft-polymer were characterized by Infrared spectrometer (IR), 'HNMR and Thermo-gravimetric Analysis (TG) respectively. The physical- mechanical properties, thermal properties and microscopic structure of the SMA/PU blends were analyzed by Differential Thermal Analysis (DTA) and Scanning Electron Microscope (SEM).The results show that the graft-polymer of SMA and PU has good thermal properties which are affected by the different soft segments of PU. The SMA/PU blends through grafting and chain coiling have good compatibility and adhesion in the phase interface. Compared with the pure PU and SMA, the SMA/PU blends not only have the better thermal stability and tensile strength, but also a very good elasticity. When the content of SMA is about 10-15%, the SMA/PU blends have the comprehensive properties.The results also show that the SMA and PU which can be synthesized easily through reactive blending can gain the blends with good properties, which can decrease the productions costs and extend the applied fields of the blends materials. Therefore the SMA/PU blends have good practical prospects.