Electron beam curable p-t-butylphenol-formaldehyde resin

In this paper electron beam-curable prepolymers were prepared by the addition reaction of p-t-butylphenol formaldehyde resin with glycidyl methacrylate, and electron beam curing was studied for the prepolymers and their mixtures of several kind of vinyl monomers. When the reaction was carried out in the presence of triethylbenzyl ammonium chloride catalyst without solvent, the rate of the addition reaction obeyed first-order kinetics. Electron beam-curing was carried out at a dose rate of 3 Mrad/sec. It was found that the prepolymer could be cured at a dose of 2 Mrad and when the mixtures of prepolymers containing 30% monomer, the rate of gel formation increased in the order 2-ethyl hexyl methacrylate < styrene < butyl acrylate < ethyl acrylate. In the curing of the mixtures of prepolymer with polyethylene glycol dimethacrylates, miximum gel formation was observed at 10% monomer content at a dose 1 Mrad. However, miximum gel formation was observed at higher monomer content as the total dose increased. In this case the rate of gel formation increased with the increase in the degree of polymerization of the polyethylene oxide fraction of the polyethyleneglycol dimethacrylate. (author)