Silicone - Polyurethane Copolymer And Performance Studies

Polysiloxane polymers possess important physical and chemical properties due to its unique structure. These properties include low glass-transition temperature, very good resistance to temperature and oxidant agents, good electrical insulting qualities and thermal stability, high permeability to gases, biocompatibility and etc. But they exhibit rather poor mechanical properties and low adhesive force, which restricts their application very seriously. Poiyurethane polymers consist of alternating hard and soft segments, which show superior mechanical properties but reduced thermostability. The copolymer of polysiloxane and poiyurethane combining their advantages can improve the properties of polysiloxane and poiyurethane. Polysiloxane-polyurethane copolymer which would render better heat resistance and lower temperature flexibility than polyurethanes themselves and better mechanical strength and abrasion characteristics than polysiloxanes has the potential application as new material.In this paper, polyether-silicone oil was prepared via hydrosilylation reaction by H-containing of silicone oil and unsaturated polyether, with platinum-divinyltetramethyldisiloxane complex [Pt (0) Karstedt catalyst] as catalyst. This polymer was characterized by Fourier transform infrared spectroscopy (FT-IR) and ~1H nuclear magnetic resonance (~1H-NMR) measurements. Effect of react temperature, react time and amount of catalyst on hydrosilylation reaction are investigated. Results showed that the optimal reaction temperature is 80~100°C, reaction time is about 4 hours and the amount of catalyst is about 0.4wt‰ of polyether.The polysiloxane-polyurethane (PSi-PU) copolymer (no chain extender) was synthesized from toluene diisocyanate (TDI) and polyether-silicone oil. And the effect of amount of TDI, silicone oil and curing temperature on mechanical properties and water uptake property of copolymer were studied. The results showed that copolymer exhibited poor mechanical properties and rather high water uptake ratio. The mechanical properties of PSi-PU copolymer were increased and the water uptake ratio was decreased with the increase of amount of TDI; suitable amount of silicone oil can enhance the mechanical properties and decreased the water uptake ratio of copolymer;...