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:
A high molecular weight poly(ethylene oxide) is gelled by radiation from a 60Co source. At concentrations of 0.25 to 1 wt-%, doses of 4.5 to 7.5 × 104 rad cause gelation. The storage modulus of the gel formed increases linearly with additional dose to a plateau value and then remains constant during further irradiation. The does needed to reach the plateau, Dp in rads, and the plateau modulus Gp in dynes per square centimeter, are related to the concentration c, in weight per cent: Dp = 1.05 × 106c and Gp = 1.75 × 104c2.5. The energy absorbed by the polymer per crosslink formed is about 80 ± 10 kcal/mol. The crosslink density produced by radiation is calculated from the measured modulus by using the theory of rubber elasticity. Both modulus and loss are measured in a special air-bearing, recording torsion pendulum with a coneplate geometry.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/app.1968.070120912
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