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:
Glass transition temperatures of oxidative polymerized films were measured by the dynamic-mechanical method and by line-width measurements (NMR). The correlation was studied in relation to the chemical structure. The films investigated were polymerized linseed oil, alkyd resins, phenolic varnishes, and polyester-urethane films. It is found that the effects of chain stiffness and the degree of crosslinking predominate in Tg measured by the dynamic-mechanical method, whereas the effect of polar groups is most important on Tg measured by line-width measurement. It was previously reported that Tg as measured by the line-width measurement increased with the degree of crosslinking in vulcanized rubbers. This was not observed in films of phenolic varnishes, as the variation of the polar groups was involved. The meaning of Tg measured by different methods is also discussed from the thermodynamic standpoint.
Additional Material:
11 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/app.1965.070091102
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