Production of elastomeric 1,3-diene polymers having improved strength and elongation

1,127,135. Diene graft polymers. BADISCHE ANILIN- & SODA-FABRIK A.G. 1 Dec., 1965 [2 Dec., 1964], No. 50911/65. Heading C3G. 1,3-Dienes are polymerized in aqueous emulsion using a polymerization catalyst and in the presence of a diene polymer which has a crystallinity of more than 30% and a molecular weight of 15,000 to 1,500,000. The reaction is carried out at - 10‹ to 100‹ C. at a pressure of 1 to 20 atmospheres absolute. The catalysts may be inorganic or organic peroxides, redox systems or metal chelate complexes such as those described in Specification 1,065,406 and may be supplied to the polymerization vessel as an emulsion in a portion of the aqueous reaction medium. The partly crystalline diene polymers are generally derived from linear or branched aliphatic 1,3-dienes having 4 to 6 carbon atoms and are exemplified by 1,4-trans polyisoprene, 1,4-trans-butadiene and a polyisoprene having a 1,2-vinyl fraction of less than 10%; they are preferably supplied to the graft reaction in solution in hydrocarbons or emulsified, and may be supplied either continuously or intermittently during the polymerization. Suitable 1,3-dienes having 4-10 carbon atoms are butadiene, isoprene, 2,3-dimethylbutadiene, 2-phenylbutadiene, and 2-chlorobutadiene. In Examples 1 and 3, the 1,3-dienes are partially polymerized before the partially crystalline diene polymer is added. Monoethylenically unsaturated compounds, such as (a) α,#- ethylenically unsaturated aliphatic monocarboxylic acids having 3 or 4 carbon atoms and their esters particularly with alkanols having 1-8 carbon atoms, (b) esters of fumaric acid and maleic acid particularly with alkanols having 1-4 carbon atoms, (c) acrylic and/or methacrylic compounds such as their amides, nitriles and N-methylol derivatives thereof, (d) vinylaromatic compounds having one benzene nucleus, (e) vinyl ethers particularly of alkanols having 1-4 carbon atoms, and (f) vinyl ketones having 4 or 5 carbon atoms, may be copolymerized with the 1,3-dienes provided that these 1,3-dienes comprise at least 50% by weight of the total monomers.