The role of the amorphous phase in melting of linear UHMW-PE : implications for chain dynamics

摘要: In ultra-high molecular weight polyethylene (UHMW-PE), it is possible to obtain single chain forming crystals, where chains are adjacently re-entrant. Depending on the heating rate, feasible melt these crystals either by simple consecutive detachment of stems from crystalline substrate or cluster melting, several involved. The occurs at melting point predicted Gibbs–Thomson equation, whereas much higher temperatures. Melting crystal and their diffusion in ultimately result a new state having heterogeneous distribution physical entanglements, which invokes differences local mobility. With combined DSC, rheology solid-state NMR studies, concluded that disentangled domains present within entangled matrix possess mobility than domains, causing lower elastic modulus. fraction maintained temperatures, leading thermodynamically non-equilibrium state. contrast, (initially disentangled) can simultaneously adopt random coil state, entanglements formed homogeneously distributed melt. paper influence topological amorphous phase semi-crystalline polymer kinetics crystals. reported findings have implications for behaviour resulting polymers general.