Synthesis and characterization of phosphorus-containing methacrylate-based difunctional crosslinkers and their use in UV-curable resin systems

Abstract

Two new phosphorus-containing methacrylate-based difunctional crosslinking agents (bis(4-(2-methacryloyloxy)ethyl carboxyl)phenyl phosphine oxide (BEPPPO) and bis(4-(2-methacryloyloxy)ethylcarbonylaminophenyl)phenyl phosphine oxide (BUPPPO)), which can be good candidates for UV-curable coating applications, were synthesized by reacting either a phosphorus-containing diisocyanate (bis(4-iso- cyanatophenyl)phenyl phosphine oxide) or a phosphorus-containing diacid chloride (bis(4-chloroformylphenyl)phenyl phosphine oxide) with hydroxyethyl methacrylate. The structures of the monomers thus obtained were characterized by FTIR, mass, and 1 H-NMR spectroscopies. The contents of the new crosslinking agents in the UV-cured polymeric films were varied between 10 and 30% by weight. Mechanical, physical, and thermal characterizations of the UV-cured films were investigated. An increase in crosslinking agent content caused an increse in mechanical properties. Films contain- ing BUPPPO had higher tensile strength values compared to the films containing BEPPPO. Thermogravimetric analysis of phosphorus-containing crosslinking agents revealed that incorporating phosphorus into the structure resulted in a high char yield up to 24.5% at 600°C. Water absorption values of UV-cured films were also affected by the amount and type of crosslinking agent. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 2575-2585, 1999