Effect of short‐chain polymer on scission of long‐chain polymer in solution by high‐speed stirring

Abstract The effect of short‐chain poly(methyl methacrylate) (PMMA) (P̄v = 950) on scission of longchain PMMA (P̄v = 6150) in solution by high‐speed stirring was investigated by measuring changes in [η] and GPC, stirring at 30,000 ± 500 rpm at 30° ± 5°C benzene solutions containing the above two polymers at several concentrations and at various mixing ratios. It was found that the scission of long‐chain PMMA was small or a little suppressed by addition of short‐chain PMMA. The scission‐suppressing effect of the coexisting polymers depended on the chain length. The longer the chain, the larger the effect. It was also found that the rate constant of scission, k, in Ovenall's equation had a certain significance in polymer systems with the same MWD but no significance in those with different MWDs.