Melting behavior of polyethylene crystallized in a pressure capillary viscometer

An experimental program is presented in which crystalline strands of HDPE, that have been produced in the Instron capillary rheometer, were investigated by means of Perkin- Elmer differential Scanning calorimeter (DSC). The data obtained include the magnitude of the melting points as well as the melting point values as a function of the heating rates. DSC results obtained on irradiated strands are presented in order to demonstrate the multiplicity of structures existing in the strands. In addition, birefrigence measurements arebtained. From the birefrigence information and a supporting DSC study on paraffins, observations are made concerning the definition of the melting point from fusion curves observed on the disk.