ISSN:
0449-296X
Keywords:
Physics
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
A direct method has been developed for determining G(crosslinks) for irradiated polymers using the analytical ultracentrifuge. The sedimentation velocity technique is employed to follow changes in the molecular weight of a narrow distribution polystyrene sample irradiated in vacuum with 60Co γ-rays. It is shown that G(crosslinks) can be determined at low doses before significant structural changes have occurred in the polymer. At about one-fifth of the gel dose G(crosslinks) was found to be 0.019 compared to a value of 0.040 obtained from gel-sol fraction measurements. It is concluded that G(crosslinks) may increase with dose due to processes such as the addition of radicals to double bonds formed during the irradiation.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1968.150060315
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