ISSN:
0021-8995
Keywords:
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
,
Physics
Notes:
Continuous-wave rapid-passage proton NMR (30 MHz) was performed on lightly crosslinked natural cis-polyisoprene at elongations up to 720%, at temperatures between -100° and 100°C, and after delays of up to several weeks after stretch. A method of separating the spectra into a narrow and a wide component was developed and applied. The results are interpreted in terms of the effects of a glass transition and strain-induced crystallinity and are in general agreement with results by other methods. The degree of crystallinity is found to increase strongly with strain (from zero for unstretched samples to 31% at elongations of 720% at room temperature), to increase with time, reaching equilibirium most rapidly in the most highly strained samples, and to decrease approximately linearly with temperature above about 20°C.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/app.1977.070210605
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