ISSN:
1042-7147
Keywords:
poly(ethylene naphthalate-2,6-dicarboxylate) (PEN)
;
monofilament processing
;
network parameters
;
birefringence
;
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
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.
Additional Material:
12 Ill.
Type of Medium:
Electronic Resource
Permalink
