Polymerisation of dimethyl-butadiene - catalysed with a mixt. of a cobalt cpd. an nn aluminium cpd. and a phosphorous acid

摘要

Prepn. of poly-2,3-dimethyl-1, 3-butadiene contg. is not 30% of 1,2 linkages is by polymerisation of 2,3-dimethyl-1, 3 butadiene (I) in the presence of a catalyst consisting of (i) an organic Co cpd. (ii) an Al organic cpd. and opt. (iii) a phosphorous acid ester. The polymer is produced in high yield, with no cyclisation, and high mol. wt. It has excellent tensile strength, Modulus (300%) and a very good tear resistance. Values obtd. for these properties are better than for cis. BR and emulsion SBR. The polymer is used for the prodn. of e.g. tyres, shoe soles, carrier bands. In an example, 30 g 2,3-diMe-1, 3-butadiene, 0.06m Mol Co-octanoate, 0.06 mMol P(OC6H5)3 and 1.5 mMol Et3Al2Cl3 were added in succession to 150 ml dry cyclohexane and polymerised at 50 degrees C for 3 hours. A normal stabiliser was added to stop the reaction and the polymer was obtd. by pptn. Product is used for e.g. car tyres and other rubber articles.