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Enhancement of the dimensional stability of poly(ethylene‐2,6‐naphthalene dicarboxylate) filament by multistep zone annealing spinning
Author(s) -
Chae Han Gi,
Chae Dong Wook,
Kim Byoung Chul,
Seo Seung Won
Publication year - 2001
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.10148
Subject(s) - spinning , materials science , differential scanning calorimetry , composite material , annealing (glass) , thermal stability , melt spinning , ultimate tensile strength , protein filament , glass transition , shrinkage , melting temperature , polymer , chemical engineering , thermodynamics , physics , engineering
Both good tensile properties and good resistance to thermal shrinkage are prerequisites for tire cord applications. For these purposes, poly(ethylene‐2,6‐naphthalene dicarboxylate) (PEN) filaments were prepared by multistep zone annealing (MSZA) spinning with a specially devised system. The melting temperature of the PEN filaments so obtained was slightly increased with an increasing total draw ratio. All the filaments exhibited a sharp melting peak around 270°C, but glass‐transition behavior was barely visible via differential scanning calorimetry. Rheovibron experiments showed α relaxation in the vicinity of 175°C. Increasing the draw ratio above 4 did not increase the birefringence value much, but it did lead to increases in the tensile properties. The PEN filaments consisted exclusively of α‐form crystals. The PEN filaments showed excellent resistance to thermal shrinkage, which was less than 1% even with heating to 140°C. In the MSZA spinning process, increasing the degree of hot drawing proved more effective than increasing the degree of cold drawing for obtaining PEN filaments with better dimensional stability at elevated temperatures. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 916–922, 2002