Superheated Melting Kinetics of Metastable Chain-Folded Polymer Crystals

The unique behavior of superheated melting kinetics of polymer crystals has been examined in terms of the metastable nature of thin polymer crystals with chain folding. The superheated melting kinetics was characterized by the heating rate dependence of the melting peak in the thermogram. By examining the behaviors of polyethylene molar mass fractions, its homologue, hexacontane, and indium, it has been experimentally confirmed that the metastability of crystals with chain folding has an essential role in the superheated melting kinetics; i.e., stable extended-chain crystals of hexacontane melts in the same way as indium without superheating, and metastable chain-folded crystals of higher molar mass polyethylene needs to overcome a larger kinetic barrier for melting.