Synthesis and characterization of degraded gelatin grafted poly(ɛ-caprolactone) copolymers

Abstract

Hydrophilic degraded gelatin was modified with hydrophobic poly(ɛ-caprolactone) (PCL) via a chemical grafting route. Firstly, PCL with one hydroxyl end group was prepared by the ring-opening polymerization of ɛ-caprolactone (ɛ-CL) with tin (II) 2-ethylhexanoate as catalyst and n-butyl alcohol as initiator. Secondly, the PCL reacted with isophorone diisocyanate (IPDI) to prepare PCL with isocyanate functional group (PCL-NCO). Hydroxylamine was used to degrade gelatin by the cleavage between asparagine and glycine residues of gelatin. PCL-NCO reacted with the hydroxyl/amino groups of degraded gelatin in a homogeneous system and yielded the PCL modified gelatin copolymers. The gelatin grafted PCL copolymers were measured by means of XRD, FTIR, DSC and ¹H NMR. The results confirmed the conjugation of PCL onto gelatin chains. The PCL modified gelatin can be used as biomaterials owing to their biocompatibility and biodegradation.

Keywords

degraded gelatin / poly(ɛ-caprolactone) / modification / grafted copolymers / biomaterials

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