Aging and degradation of polyolefins. III. Polyethylene and ethylene-- propylene copolymers

Journal Article · Thu Nov 01 04:00:00 EST 1973 · J. Polymer Sci., Polym. Chem. Ed., v. 11, no. 11, pp. 2879-2898

DOI:https://doi.org/10.1002/pol.1973.170111110· OSTI ID:4375251

Decker, C; Mayo, F R; Richardson, H

Rates of oxygen absorption and formation of oxidation products were determined in gamma -initiated oxidations of thin films of highand low-density polyethylene, atactic and isotactic polypropylene, and of three ethylene-- propylene copolymers. Radiation yie1ds G for O/sub 2/ absorbed and formation of hydroperoxides depend on dose rates and decrease sharply with increasing ethylene content of the copolymers and moderately with increasing crystallinity of any base polymer. G values for dialkyl peroxide and carbonyl formation, and therefore for chain initiation and termination, do not change much with polymer composition and crystallInity and not at all with dose rates. A few experiments with atactic polypropylene and an amorphous ethylene--propylene copolymer, initiated by ditert-butylperoxy oxalate, indicate that 37 mole% of ethylene in the polymer increases the efficiency of initiation and the tendency toward crosslinking. (auth)

• Research Organization: Stanford Research Inst., Menlo Park, CA
• Sponsoring Organization: USDOE
• NSA Number: NSA-29-012599
• OSTI ID: 4375251
• Journal Information: J. Polymer Sci., Polym. Chem. Ed., v. 11, no. 11, pp. 2879-2898, Journal Name: J. Polymer Sci., Polym. Chem. Ed., v. 11, no. 11, pp. 2879-2898; ISSN JPLCA
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

*POLYETHYLENES-- CHEMICAL RADIATION EFFECTS
*POLYPROPYLENE-- CHEMICAL RADIATION EFFECTS
COPOLYMERIZATION
DECOMPOSITION
G VALUE
GAMMA RADIATION
N40300* --Chemistry--Radiation Chemistry
OXIDATION
OXYGEN
RADIATION CHEMISTRY
TIME DEPENDENCE