UV-CURABLE HYBRID PRIMERS COMPOSED OF VINYL TERMINATED POLYURETHANE ACRYLATE OLIGOMERS AND VINYLTRIMETHOXYSILANE (VTMS) FOR ALUMINIUM-POLYCARBONATE INTERFACES

Organic-inorganic hybrid primer molecules based on vinyltrimethoxysilane (VTMS) and polyurethane acrylates (PUA) of various structures have been designed, synthesized, and tested for aluminum-polycarbonate interface which is typical for metalizing coating of automobile. It was found that the optimum VTMS concentration for lap shear strength was 1.0mM implying that at this concentration most of the OH groups exposed to the surface of aluminum panel are subjected to the sol-gel reactions with VTMS to form presumably monolayer, as noted from the contact angle measurements. Among three different types of polyols being incorporated as soft segment of PUA, polycaprolactone diol (PCL) diol gave much greater adhesion strength than polypropylene glycol (PPG) and polytetramethylene glycol ( PTMG) based PUA due to its miscible nature with the substrate, viz. polycarbonate.