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Novel in situ NMR Measurement System for Evaluating Molecular Mobility during Drawing from Highly Entangled Polyethylene Melts
Author(s) -
Kakiage Masaki,
Uehara Hiroki,
Yamanobe Takeshi
Publication year - 2008
Publication title -
macromolecular rapid communications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.348
H-Index - 154
eISSN - 1521-3927
pISSN - 1022-1336
DOI - 10.1002/marc.200800316
Subject(s) - amorphous solid , relaxation (psychology) , materials science , polyethylene , in situ , polymer , spectrometer , molecular dynamics , quantum entanglement , chemical physics , orientation (vector space) , polystyrene , component (thermodynamics) , nuclear magnetic resonance , molecular physics , crystallography , composite material , chemistry , optics , physics , organic chemistry , thermodynamics , computational chemistry , quantum , psychology , social psychology , mathematics , quantum mechanics , geometry
A novel in situ measurement system for evaluating molecular mobility during uniaxial drawing of polymeric materials was established by introducing drawing and stress‐detecting devices into a 1 H pulse nuclear magnetic resonance spectrometer. In this study, we analyze the changes in molecular motion of amorphous chains during melt‐drawing of ultra‐high molecular weight polyethylenes (UHMW‐PEs) with different molecular weight distributions. In the initial stage of drawing, a three‐component resolution was possible for the relaxation decay curve, which includes “rigid”, “intermediate”, and “mobile” amorphous components. The quality and quantity changes in these components demonstrated that this intermediate amorphous component could be regarded as the index of the change in molecular entanglement characteristics during the orientation of PE chains.