Quantum beam studies on polymer crystallization under flow

Abstract

One of the longstanding issues in polymer science is crystallization of polymers under flow, especially formation of the so-called shish-kebab. Recent progress in quantum beam technology shed light on the substantial nature in the shish-kebab formation. In this paper we review our recent experiments on polymer crystallization under flow using time-resolved depolarized light scattering, small-angle and wide-angle X-ray scattering and small-angle neutron scattering in a wide spatial scale from 0.1 nm to several tens μm. These studies revealed that the shish-kebab formation is governed by a competition between the crystallization rate and the chain relaxation rate. Small-angle neutron scattering study on an elongated blend of deuterated low molecular weight and protonated ultra-high molecular weight polyethylenes showed that a long cylindrical object 2 μm in diameter and 12 μm in length was formed from deformed network of ultra-high molecular weight chains, which included three shishs (or extended chain crystals) 9 nm in diameter. © 2007 The Society of Polymer Science.