Synthesis, Characterisation and Properties of Polyurethane Grafted Chlorinated Polypropylene and its Composites

The performance of chlorinated polypropylene (CPP) can be improved by grafting polyurethane (PU) onto it. PU grafted CPP (PU-g-CPP) has been synthesised via the inter-chain polymer reactions between maleated CPP (MCPP) and PU prepolymers containing free isocyanate (NCO) group in the presence of xylene as solvent and tertiary amine as catalyst. Various conditions for the reaction and the performance of the graft mixture (PU/MCPP composites) were optimised. The potential crosslinking and gelation were avoided successfully by dropping MCPP and controlling the mole ratio of PU prepolymers to MCPP. Different PU prepolymers and extenders had distinct effects on the solidifying characteristics and the adhesive capacity of PU/MCPP composites. The target graft products were characterised by FT-IR spectroscopy and differential scanning calorimetry (DSC) techniques.