Preparation and Characterization of Thermoplastic CPP modified Acrylic copolymer

The age-old problem of obtaining good adhesion of paints, coatings, sealants and glues to traditionally hard to bond to materials like polypropylene (PP) as low surface energy substrate has challenged engineers for years. Grafting of (meth)acrylic monomers to chlorinated polypropylene (CPP) as subcategorized of chemical surface treatment is a way to functionalize the surface of plastic materials and improvement of wetting ability and adhesion strength as intermediate layer. Acrylic and methacrylic monomers were successfully grafted onto CPP in 5,10 and 20% mass ratio via solution polymerization based on TACRYL TP44 formulation. The modified CPP was characterized by FTIR after purification. Industrial requirements were investigated through the measurement of physical-mechanical properties of resin individually in comparison with TACRYL TP44 (without adhesion promotor) coated with different dilution ratio (1, 5%) and wet film thickness 30 μm on PP and using as primer for TACRYL 765X (2k polyurethane) topcoat. The X-cut, bending and MEK rubbing results indicated that the optimum characteristics of lacquer and coating systems on untreated PP substrate was on 5 % grafting mass ratio and 1% dilution in constant thickness.