Radiation degradation study of poly(methyl. cap alpha. -chloracrylate) and the methyl methacrylate copolymer

Journal Article · Wed Nov 01 00:00:00 EST 1978 · Macromolecules; (United States)

DOI:https://doi.org/10.1021/ma60066a008· OSTI ID:5900468

Helbert, J N ^[1]; Chen, C Y; Pittman, Jr, C U; Hagnauer, G L

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1. Army Electronics Technology and Devices Lab., Fort Monmouth, NJ

High molecular weight samples of poly(methyl ..cap alpha..-chloracrylate) and poly(methyl ..cap alpha..-chloroacrylate-co-methyl methacrylate) were prepared by emulsion polymerization techniques. These polymers were fractionated and exposed to varying doses of ..gamma.. radiation from a /sup 60/Co source. The G/sub s/ - G/sub x/, G/sub s/, and G/sub x/ values were determined from anti M/sub n//sup -1/ vs. dose and anti M/sub w//sup -1/ vs. dose plots. Analysis of the molecular weights was performed by membrane osmometry, light scattering, and gel permeation chromatography (GPC). The value of G/sub s/ for poly(methyl ..cap alpha..-chloracrylate) was found to be 6.0 +- 0.9 and G/sub x/ = 0.7 +- 0.2 from a combination of light scattering and osmometry measurements. The corresponding values from GPC studies were 7.4 +- 0.9 and 0.9 +- 0.2, respectively. G/sub s/ and G/sub x/ were not dependent on molecular weight. The homopolymer undergoes ready scission which is complicated by concurrent cross-linking. The G/sub s/ - G/sub x/ value for a copolymer with 41% methyl ..cap alpha..-chloroacrylate was 2.8 +- 0.3 and this value was independent of molecular weight. Furthermore, this value is about 41% of the difference between that of the two homopolymers suggesting that G/sub s/ - G/sub x/ may be linearly related to copolymer composition. The degradation mechanism is discussed in light of these data and ESR measurements.

• OSTI ID: 5900468
• Journal Information: Macromolecules; (United States), Vol. 11
• Country of Publication: United States
• Language: English

Related Subjects

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
36 MATERIALS SCIENCE
METHYL METHACRYLATE
RADIOLYSIS
POLYACRYLATES
CHLORINATED ALIPHATIC HYDROCARBONS
ELECTRON SPIN RESONANCE
EXPERIMENTAL DATA
G VALUE
GAMMA RADIATION
CARBOXYLIC ACID ESTERS
CHEMICAL RADIATION EFFECTS
CHEMICAL REACTIONS
CHEMISTRY
DATA
DECOMPOSITION
ELECTROMAGNETIC RADIATION
ESTERS
HALOGENATED ALIPHATIC HYDROCARBONS
INFORMATION
IONIZING RADIATIONS
MAGNETIC RESONANCE
METHACRYLIC ACID ESTERS
NUMERICAL DATA
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC POLYMERS
POLYMERS
POLYVINYLS
RADIATION CHEMISTRY
RADIATION EFFECTS
RADIATIONS
RESONANCE
400600* - Radiation Chemistry
360405 - Materials- Polymers & Plastics- Degradation & Erosion- (-1987)