ISSN:
0032-3888
Keywords:
Chemistry
;
Chemical Engineering
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:
The effects of moisture and rather large doses of reactor radiation (∼4 × 1011 ergs/gm) on the dynamic properties of polymerized epoxy resins have been investigated over the temperature range of 80°-450°K and at frequencies from 200 to 1400 cps. Data are presented for both unfilled and aluminum-filled systems of a bisphenol A based epoxy, (Epon 828) cured with metaphenylenediamine. Moisture absorption (0.88%) causes a shift of the main glass transition near 440°K to lower temperatures (∼25 degrees for unfilled epoxy). This is similar to the plasticizing action of small molecules absorbed in other polymers such as nylon 6-6. Irradiation to a dose of 4 × 1011 ergs/gm (4 × 109 rads) causes a shift to lower temperatures (∼50 degrees) of the onset of the main transition, and, in addition, results in both a shift to lower temperatures and a decrease in maximum height of the damping peak near 250°K. Chain scission, in a loosening of the structure and the breaking up of the partially flexible connecting groups, may be responsible for these radiation effects.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pen.760020106
