GB884706A - Polymerization with organo aluminum compounds - Google Patents

Abstract

Esters of acrylic and methacrylic acids are polymerized with the aid, as a catalyst, of an organo aluminium compound of the formula <FORM:0884706/IV (a)/1> where R, R11 and R111 represent hydrocarbon groups, although one R may represent hydrogen, the polymerization being carried out in the substantial absence of water, oxygen, or any other substance which would interfere with the reaction. Polymerization may be carried out in bulk or in solution in an inert solvent such as benzene, toluene, xylene, naphtha or diethyl or dibutyl ether. Organo aluminium compounds specified are those in which the hydrocarbon groups are alkyl, cycloalkyl, aralkyl or aryl groups, e.g. trimethyl, triethyl, tripropyl, triisopropyl, tributyl, tricyclohexyl, triphenyl, tritolyl, trinaphthyl and tribenzyl aluminiums, and diethyl, diisopropyl and diphenyl aluminium hydrides. Preferred polymerizable esters are those of the formula CH2 = C(R)COOR DEG where R is hydrogen and R DEG is an alkyl, alkenyl, cycloalkyl, phenyl or aralkyl group, e.g. methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, octyl, 2-ethylhexyl, 3,5,5-trimethylhexyl, dodecyl, tetradecyl, hexadecyl, octadecyl, cyclopentyl, cyclohexyl, methlcyclohexyl, phenyl, benzyl, methyl benzyl, allyl, pentenyl, undecenyl and oleyl groups. The process may be employed to homopolymerize the above esters or to copolymerize them with one another. At the end of the reaction, and before the destruction of catalyst, the tendency for the polymer to cross-link on exposure to oxygen may be overcome by treating the reaction product with a compound having a reactive hydrogen atom, e.g. a C1-C4 alkanol, a methanolic solution of hydrochloric or acetic acid, an ethanolic solution of acetic acid, a nitroparaffin, a malonic ester or an acetoacetic ester.