ISSN:
0449-2978
Keywords:
Physics
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
Isotactic 3-methylbutene homopolymers and copolymers (of low 1-olefin content) exhibit a major transition between 50 and 100°C, which dilatometric, density, and NMR observations indicate is not a glass transition, but rather a crystal-crystal transition occurring within the crystalline phase, the only phase present in significant amount. Fibers prepared from these polymers show a very high degree of orientation and crystallinity, have measured densities close to the theoretical crystal densities, and exhibit abrasion debris and electron microscopic evidence of crystalline lamellae. The fibers have a quasistatic initial modulus equivalent to the sonic modulus and exhibit very low stress relaxation and very high elastic recovery from large extensions. The fact that the fiber is highly crystalline and fully oriented, with a comparatively low initial modulus, high elastic recovery, and an extensibility of about 40%, indicate that the crystalline lamellae themselves, joined together in stacks, are able to deform (probably bend) elastically, and that the aggregate is able to undergo large elastic deformations.
Additional Material:
12 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1970.160081111
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