초록 |
Polyurethane-silica nanocomposites having shape memory effect were prepared using a 3-aminopropyltriethoxysiliane(APTES) as chain extender to formed cross-linked structure with nano-sized silica particle(Aerosil 200) by sol-gel process. The reaction of APTES and Aerosil 200 was traced with 29Si-NMR. Dynamic mechanical thermal analyzer(DMTA), cyclic tensile test, and hardness(shore A) were employed to characterize the shape memory polyurethane(SMP) nanocomposites. These tests showed that the mechanical properties were largely improved. The cross-linked SMP-nanocomposites by sol-gel process could recover their original shape completely. Consequently, by introducing silica nanocomposites the mechanical properties of SMP were improved without sacrificing shape memory effect. |