Crystallization rates of moderate and ultrahigh molecular weight polyethylene characterized by Flash DSC measurement

We compared crystallization rates in three bulk commercial polyethylene samples separately consisting of two ultrahigh molecular weights and one moderate molecular weight. The lower-end temperature of isothermal crystallization was expanded by means of Flash DSC measurement in order to approach the practically fast crystallization region. The results showed that, in the whole temperature range of our observations, ultrahigh molecular weights make polyethylene crystallization faster than moderate molecular weights. This behaviour is opposite to the general trend in linear polymers. In addition, ultrahigh molecular weights make polyethylene crystals resist fast heating before melting more than moderate molecular weights, due to high entanglement around the crystals. We discuss the possible mechanism of fast crystallization in ultrahigh molecular weight polyethylene, which is beneficial for prosthesis uses. (c) 2019 Society of Chemical Industry