The bulk photopolymerization of methyl methacrylate at 30℃ was studied. In case of stronger light intensity

the rate of polymerization is no longgr proportional to the square root of light intensity. And a plot of the reciprocal of viscosity-average degree of polymerization against rate of polymerization is an upward curve rather than a straight line. These results are discussed in terms of primary radical termination reactions.By comparing the data of the photopolymerization of methyl methaerylate at 30℃ with those of benzoyl peroxide initiated polymerization at 60℃

it clearly shows that primary radical termination is more important at lower temperature than at higher temperature.