{'fraction_non_alphanumeric': 0.022483940042826552, 'fraction_numerical': 0.0, 'mean_word_length': 5.360544217687075, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Effect of Molecular Weight on Phase Transition of Polyethylene under High Pressure

The effect of the molecular weight distribution which makes polyethylene (PE) behave as a multi-component system in the phase transition under high pressure suggested by the authors from thermal study was confirmed by an X-ray method. Fractionated PE crystallized into an extended-chain crystal (ECC) showed the equilibrium successive first-order phase transition of a one-component system. But a PE mixture of two different molecular weights or unfractionated PE crystallized into ECC showed continuous melting of hexagonal solid characteristic of the melting of binary or multi-component systems. PE crystallized into folded-chain crystal (FCC), on the other hand, showed no equilibrium transition. These results confirm our previous suggestion and it is concluded that only monodisperse ECC-PE can be regarded as a thermodynamically pure material.