Zero growth temperature of crystallizing polyethylene

The zero growth temperature of linear polyethylene was analyzed by by polarizing optical microscope in a temperature range of high crystallization temperatures. A linear polyethylene was selected and its growth was observed at a series of temperatures which were passed through a stepwise heating. The results show that the crystallization of polyethylene is controlled by two characteristic temperatures at different crystal thickness and growth rates. The results also show that the mesomorphic phase of polyethylene is identical with the hexagonal phase stable under high pressure-high temperature conditions. At normal pressure conditions a value of 134°C for the temperature is obtained for the hidden transition between amorphous and the mesomorphic polyethylene. The results also show that a crystallization mediated by a transient mesomorphic phase is reached at 131°C.