INVESTIGATION OF HETEROGENEOUS NUCLEATION BY THE INDUCTION TIME OF CRYSTALLIZATION .2. COMPARISON OF THE THEORY AND EXPERIMENTAL-MEASUREMENT

The nucleation of polypropylene on the surfaces of carbon and polyimid e fibres was investigated by induction time measurement. The theory of induction time was used to analyse experimental results. It follows f rom this analysis that surfaces of the high-modulus carbon fibres gene rate nonepitaxial nucleation, whereas the high-strength carbon fibre a nd polyimide fibres generate epitaxial nucleation. On the basis of the induction time theory, quality of nucleation sites of the investigate d fibres could be evaluated. It was found that epitaxial nucleation do es not necessarily yield transcrystalline structure; instead separate epitaxially nucleated spherulites were observed on high-strength carbo n fibre and on some polyimide fibres. Copyright (C) 1996 Elsevier Scie nce Ltd.