Radiation chemistry of isotactic and atactic polypropylene. I. Gas evolution and gas studies
A study was made of gas evolution and gel formation when both atactic and isotactic polypropylene are irradiated by Co-60 gamma rays in vacuo at room temperature. The G-value for hydrogen evolution, 2.7, is somewhat less than for polyethylene, while G(CH4) is 0.08. The gas from the irradiation of atactic polypropylene contained more methane and less hydrogen than that from the isotactic sample. The gel data can be interpreted on the basis of the CharlesbyPinner gel equation, but very low values for cross-linking are obtained. It is concluded that the cross-linking G-value, G(X), lies between 0.058 and about 0.3, that G(X) for isotactic polypropylene is about 0.6 that of atactic polypropylene, that most of the hydrogen evolution results in double bond formation or possibly intramolecular cross-linking, and that G(S) is practically identical for atactic and isotactic polypropylene. These conclusions are for G- values beyond the gel point and are estimated assuming constancy of G-values with dose.
- Research Organization:
- Northwestern Univ., Evanston, Ill.
- Sponsoring Organization:
- USDOE
- NSA Number:
- NSA-17-012343
- OSTI ID:
- 4760997
- Journal Information:
- Journal of Physical Chemistry, Vol. 67, Issue 2; Other Information: Orig. Receipt Date: 31-DEC-63; ISSN 0022-3654
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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