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The production and properties of poly(ethylene naphthalate‐2,6‐dicarboxylate) monofilaments
Author(s) -
Carr Paul L.,
Zhang Heping,
Ward Ian M.
Publication year - 1996
Publication title -
polymers for advanced technologies
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.61
H-Index - 90
eISSN - 1099-1581
pISSN - 1042-7147
DOI - 10.1002/(sici)1099-1581(199601)7:1<39::aid-pat488>3.0.co;2-a
Subject(s) - materials science , birefringence , composite material , shrinkage , spinning , modulus , rubber elasticity , ethylene , natural rubber , optics , biochemistry , chemistry , catalysis , physics
Experimental spinning and drawing conditions are described for poly(ethylene naphthalate‐2,6‐dicarboxylate), PEN, which produce good quality 0.5 mm monofilaments with high strength and uniformity. Mechanical properties were measured for a range of draw temperatures and draw ratios and an initial modulus of 22 GPa and a strength of 0.6 GPa were obtained by single stage drawing to a draw ratio of 6.6. The maximum birefringence achieved by single stage drawing was 0.33 compared with a theoretical maximum of 0.332 calculated from the bond polarizabilities and bond angles of the aligned monomer unit. Network parameters relevant to undrawn PEN and to the early stages in the drawing process were derived from simple rubber elasticity theory by making birefringence and shrinkage force measurements on films drawn homogeneously to low draw ratios. These suggest that the PEN network contains relatively stiff chains between entanglements and that the PEN network is modified much more in the drawing process than is the case with poly(ethylene terephthalate). A new method of measuring the birefringence of highly drawn thick filaments is described.