2-Methyl-2-cinnamoyloxymethyl-1

3-propanediol (MCO) as a chain extender was prepared.Polylactide diol (PLA diol) as soft segment

isophorone diisocyanate (IPDI) and MCO as hard segment were used to synthesize biodegradable polyurethane (PU) containing light sensitive groups.The properties of the PUs obtained were characterized by nuclear magnetic resonance hydrogen spectrum (1H-NMR)

Fourier transform infrared spectroscopy (FTIR)

gel permeation chromatography (GPC)

differential scanning calorimetry (DSC) and tensile testing.The results showed that MCO had high enough reactivity to obtain the PUs of high molecular weight

the number average molecular weight of PUs ranged from 41.9?103 to 79.0?103.Crosslinking of the PUs was realized by irradiating the PU solution with UV 365 nm light.The time for complete crosslinking of PU in solutions in the absence of light initiator (2-hydroxy-2-phenylacetophenone) was 25 min

but it was only 5 min in the presence of light initiator.The gel content increased with increasing MCO content in PUs when the PUs had the same soft segment; the gel content decreased with increasing soft segment molecular weight when the PUs had the same hard segment.Rational crosslinking contributed to the increase of tensile strength and shape recovery ratio

the shape recovery ratio of PU reached nearly 100%.