ENTANGLEMENTS FORMATION IN A DISENTANGLED POLYMER MELT
Presence of entanglements and there realisation in polymer melt is a basis of polymer processing, crystallization and thus the mechanical properties. In this paper formation of entanglements during polymerization or melting of the disentangled crystals will be discussed. To obtain disentangled crystals via crystallization from dilute solutions (involving more than 90% of solvent) is rather cumbersome and provides regular stacking of crystals which prior to melt tend to entangle 1. A more elegant route to obtain disentangled polymers, and thus to control the entanglements in the amorphous phase of a semi-crystalline polymer, is by direct polymerization in the reactor 2. Recently, it is shown that for polyethylenes varying the polymerization temperature and controlling the kinetics it is feasible to obtain highly disentangled crystals 2,3. Such crystals can be mechanically deformed below the melting point, providing fibers/tapes having the oriented extended chain crystals 2. Modulus of the tapes, obtained on simple solid state deformation of the compressed nascent powders (polymer as obtained on synthesis), matches the theoretical modulus for polyethylene crystals in the orthorhombic phase.
Sanjay Rastogi Dirk R Lippits Saeid Talebi Anurag Pandey Piet J Lemstra Christian Bailly Yao Yefeng Robert Graf Hans W.Spiess
Institute for polymer technology and materials engineering,Loughborough University,Leiscestershire L Department of Chemical Engineering,Eindhoven University of Technology,5600MB Eindhoven,The Netherlan Institute for polymer technology and materials engineering,Loughborough University,Leiscestershire L Max Planck Institute for Polymer Science,Ackermannweg 10,Mainz,Germany
国际会议
International Symposium on Polymer Physics(2008年国际高分子物理学术会议PP2008)
厦门
英文
32-33
2008-06-08（万方平台首次上网日期，不代表论文的发表时间）