| 초록 |
Porous polyurethane (PU) composites are prepared by a bulk polymerization of ether-modified dimethylsiloxane prepolymer, isophorone diisocyanate as a curing agent, and 1,4-butanediol as a chain extender in the presence of either hollow glass microsphere or hollow organic microsphere. Dynamic mechanical analyser is used to evaluate the storage modulus, loss modulus, tan delta and glass transition temperature (Tg) for each PU composite samples to show time (frequency) and temperature dependent. This polymer matrix has two glass transition temperatures on the plateau region, so the effect of the second relaxation temperature on the dynamic mechanical properties of PU composites is evaluated. The master curve of storage modulus is generated for each PU composite sample and used to predict long-term mechanical properties of PU composites under a constant sinusoidal strain of 3%. |
