Bond strength improvement of polyurethane adhesive by grafting 2-hydroxyethyl methacrylate on polyol backbone

摘要

A series of acrylated polyols were prepared by grafting 2-hydroxyethyl methacry-late(HEMA)on to polyol backbone prepared from vegetable oil fatty acid and epoxy resin.Grafting was carried out by free radical mechanism on conjugated double bond present in the polyol using benzoyl peroxide(BPO)as an initiator.Polyols and polyurethane adhesives were characterized by IR spectroscopy.Polyurethane adhesive synthesized from the modified polyols were found to provide better peel strength to styrene butadiene rubber(SBR)joints.Mode of failure was studied using Scanning Electron Microscopy(SEM).Improvement in cohesive strength of the adhesives resulted in high bonding strength.Comparative study has been carried out to determine the effect of acrylation on polyurethane adhesive by Green strength,Curing behavior,and Chemical resistance studies.Loading of 20% HEMA gave significant results.However,15% loading of HEMA resulted in a sample with highest peel strength.