Abstract:
Poly(ε-caprolactone) (PCL) diols with low average degree of polymerization (DPn is 10-50) were prepared
by bulk polymerization from ε-caprolactone initiated by the mixture of PEG400 and titanium alkoxide. These PCL
diols were used to react with 4,4′-diphenylmethane diisocyanate and 3-aminopropyltriethoxysilane in sequence
using N,N-dimethylformamide as solvent. After removal of the solvent, the silylated PCLbased polyurethanes
(SPCLU) were obtained by moisture curing. The effect of the PCL block DPn on the crosslinking, crystallization
behavior, tensile properties and shape memory properties of SPCLU networks were studied in detail. Results show
that the crystallinity, melting point, tensile modulus, and elongation at break of SPCLU increase with increasing
the PCL block DPn from 10 to 50, whereas the crosslinking density of SPCLU decreases. The SPCLUs with PCL block of
high crystallinity show good shape memory effect. The shape recovery ratio is 95%-100% and the shape recovery
temperature corresponds to the crystalline melting temperature of PCL block in the copolymer.