Uniaxial extensional flow and thermoformability of PMMA melts with very high molecular weight component

Uniaxial extensional flow behavior and processability in thermoforming are studied for poly (methyl methacrylate) samples with a very high molecular weight component in order to propose a method for predicting the processability using a small amount of samples. In uniaxial extensional flow strain-hardening behavior is observed, Thickness distribution of molded samples in the thermoforming at 160 degreesC is more uniform for the samples which exhibit the stronger strain-hardening. It is found that the strain-hardening behavior is controlled by entanglements between the high molecular weight component polymers. The degree of strain-hardening is correlated with the number of these entanglement points and the polydispersity index M-z/M-w.