SPHERULITE FORMATION IN POLY(ETHYLENE OXIDE) MIXTURES

The morphologies of three-step crystallized poly(ethylene oxide) binary mixtures are studied. In the first step, the samples isothermally crystallize at high temperature to form precursors of the spherulites (or hedrites). The following quenching process of the samples to liquid nitrogen, as the second step, shows initial stages of the spherulitic (or hedritic) development. After quenching, the samples were brought back to room temperature, and further crystallized as the third step. Many different types of immature spherulites (or hedrites) are observed. This can be explained by anisotropic initial development of the spherulites. Two different morphological portions can be generally distinguished: the main framework portion grows first from its small single crystal precursors during the quenching, and the in-filling portion develops later in the third step. Microsectors and microfacets are found in the main framework portion of the spherulites. © 1990.