On the Diffusion Mechanism in Melts of Condensation and Non-Condensation Polymers at High Temperatures

Abstract

As recently assumed DOI 10 3144 expresspoly mlett 2019 25 the diffusion mechanism in melts of noncondensation and condensation polymers at high temperatures must be rather different due to the intensive exchange trans reactions resulting in dissipation of condensation macromolecules into single repeating units Considering these peculiarities of condensation polymers it is concluded that the Reptation concept can be used for explaining the diffusion mechanism of non-condensation polymers e g polyolefins in the entire temperature interval while for condensation polymers it is applicable only in the range between Tm and approximately Tm 100 C At much higher temperatures where the exchange reactions are extremely intensive the diffusion mechanism seems to be the same as in the case of low molecular weight substances