Properties of biodegradable waterborne polyurethane modified with UV-curable grafted gelatin
Waterborne polyurethane(WPU)prepolymers with acrylate end groups were prepared using polycaprolactone diol(PCL)as the soft segment component and hydroxyethyl acrylate(HEA)as the capping agent.Vinyl graft-modified gelatin(GH)obtained from the hydrolysis-condensation reaction of vinyltrimethoxysilane(VTMS)and gelatin was introduced into the molecular backbone of WPU by covalent bonding attachment.Biodegradable WPU/GH composites were prepared by joining the vinyl groups in GH to the acrylate ends in the WPU prepolymer by UV curing.The thermal properties,heat loss properties and biodegradation properties of WPU/GH,and the change of crystallinity after degradation were tested and analysed.The results showed that covalent bonding could improve the film-forming property,water resistance and thermal stability of WPU.When the GH content reaches 10 wt.%,the degradation rate of GH/WPU chemical hybrid material reaches 68%in 0.6%lipase PBS solution and 56%in soil.