2017 年 29 巻 3 号 p. 97-101
We studied the rheological behavior of Ethylen-tetrafluoroethylene（ETFE）modified with divinyl monomer. Since the molecular structure of conventional ETFE is believed to be linear chain, the viscosity under free surface melt-flow is often insufficient for some applications. To improve the processability at various processing operations such as film casting, film blowing and blow molding, an enhancement of elongational viscosity is required due to the low melt strength. The ETFE modified with divinyl monomer showed the outstanding rheological behaviors such as high storage modulus in the low frequency region and strong strain hardening under elongational flow, while standard ETFE indicated the typical behaviors as well as other linear polymers. The enhanced nonlinear elongational behavior with prolonged relaxation time components can be explained by the formation of long-chain branches in modified ETFE.
We should note that a small amount of divinyl monomer has a strong impact on the melt rheology of ETFE. This is the first paper on an enhancement of melt rheology of ETFE at the best of our knowledge.