Phase Transition in Crystals of Semiflexible Long-Chain Molecules. I

抄録

A theory based on Kirkwood’s mean-field approximation is presented in order to elucidate the nature of a solid-state phase transition associated with rotational fluctuations about chain axes. Simultaneous equations describing states of the system are obtained and are solved for several restricted cases. A first-order phase transition with the latent heat of 19 cal/CH₂mol is predicted at 339 K for C₂₂ n-paraffine; it well explains the empirical rotational phase transition, but the latent heat is far less than experimental values.