Protective effect of the phenyl group in. gamma. -irradiated compatible blends of poly(methyl methacrylate) and poly(styrene-co-acrylonitrile)

Journal Article · Wed Feb 01 00:00:00 EST 1984 · J. Appl. Polym. Sci.; (United States)

DOI:https://doi.org/10.1002/app.1984.070290202· OSTI ID:5075307

Nguyen, T Q; Kausch, H H

The sensitivity to radiation of mixtures of poly(methyl methacrylate) (PMMA) and polystyrene-co-acrylonitrile (SAN) was studied over the entire range of composition. Polystyrene-co-acrylonitrile, like polystyrene, is highly resistant to ionizing radiation, having a small G/sub x/ value for crosslinking (0.077) and an even smaller G/sub s/ value for main chain scission (0.055). In contrast, PMMA degrades readily under irradiation (with G/sub s/ = 1.2). In ..gamma..-irradiated blends, the behavior of each polymer is largely influenced by the presence of the other component. Gel formation in SAN is impeded by PMMA, as a result of a decrease in G/sub x/, and a concomitant increase in the ratio G/sub s//G/sub x/. Flexural strength measurements, along with molecular weight determinations by gel permeation chromatography, demonstrated that SAN had a market protective effect on PMMA by decreasing G/sub s/ (chain scission). This protective effect was not observed in earlier experiments with PMMA-PS blends, in spite of its chemical similarity to the system PMMA-SAN. The difference in behavior between PMMA-PS and PMMA-SAN may be explained on the basis of polymer compatibility. PMMA and SAN form a compatible pair, whereas PMMA and PS are incompatible; thus the short range protective effect of the phenyl groups in PS is inhibited.

• Research Organization: Ecole Polytechnique Federale, Lausanne, Switzerland
• OSTI ID: 5075307
• Journal Information: J. Appl. Polym. Sci.; (United States), Vol. 29:2
• Country of Publication: United States
• Language: English

Related Subjects

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
ACRYLONITRILE
IRRADIATION
METHACRYLATES
G VALUE
GAMMA RADIATION
PHENYL RADICALS
ARYL RADICALS
CARBOXYLIC ACID SALTS
ELECTROMAGNETIC RADIATION
IONIZING RADIATIONS
NITRILES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
RADIATIONS
RADICALS
400600* - Radiation Chemistry