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Polymerization of ethylene and propylene initiated by milled alumina powder
Author(s) -
Kurokawa Norio,
Tabata Masayoshi,
Sohma Junkichi
Publication year - 1980
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1980.070250622
Subject(s) - polyethylene , radical , materials science , ethylene , polypropylene , toluene , ethylene propylene rubber , melting point , polymerization , olefin fiber , chemical engineering , polymer chemistry , catalysis , composite material , organic chemistry , chemistry , polymer , copolymer , engineering
Generation of free radicals (mechano‐radicals) by the milling of alumina powder at 77 K was demonstrated by ESR. After milling of alumina in the presence of ethylene (simultaneous milling) at 77 K, polyethylene‐propagating radicals instead of the alumina mechano‐radicals were detected by ESR. Also the contact of ethylene with the milled alumina converted alumina mechano‐radicals into polyethylene propagating radicals at a temperature above the melting point of ethylene. The products extracted by hot toluene from the simultaneous milling were identified by IR to be polyethylene, and their molecular weights were roughly 10,000. The residues after the extraction were bonded with the alumina. Polypropylene was also produced by a similar method of milling of alumina in the presence of propylene. The obtained polyproylene was atactic, and its molecular weight was about 400.