GB1311304A - Hydrogentated graft copolymers - Google Patents

Abstract

1311304 Hydrogenated graft polymer BORGWARNER CORP 22 June 1970 [27 June 1969] 30080/70 Heading C3G A hydrogenated thermoplastic graft copolymer is prepared by hydrogenating a polymeric substrate graft polymer represented by the formula A(B) x , wherein "A" is a polymeric backbone prepared from at least one monomer selected from substituted and unsubstituted conjugated dienes, substituted and unsubstituted monovinyl aromatic hydrocarbons; wherein "B" is a pendant linear polymeric chain grafted on said "A" backbone by anionic polymerization of at least one anionically polymerizable monomer selected from substituted and unsubstituted conjugated dienes and substituted and unsubstituted monovinyl aromatic hydrocarbons; and wherein "x" is a positive integer. The hydrogenation may be either complete or partial producing either monovinylaromatic substituted ethylene graft copolymers or vinyl cyclohexane substituted ethylene graft copolymers. In the preparation of the graft copolymer, prior to hydrogenation, the backbone chain may be prepared by any convenient process, after which it is dissolved or suspended in an inert hydrocarbon solvent and treated thereafter with a suitable reagent such as an organo alkali metal diamine complex to introduce active organometallic sites along the backbone chain, after which the grafting monomer(s) are added. The examples refer to partially hydrogenated graft copolymers formed from (a) styrene and 1,4- polybutadiene having respectively the following number of grafting sites, the specific examples being referred to thereafter in brackets: 3(1, 15), 7(3), 10(2, 6, 11, 14, 16), 15 (19), and 35 (13); (b) styrene and 17% 1,2-polybutadiene 10 (4, 7); (c) styrene and 60% 1,2-polybutadiene: 3 (8), 10 (5, 10, 12); (d) styrene and 64% 1,2- polybutadiene: 6(9); (e) styrene and cis polybutadiene: 10 (17); (f) styrene and cis polyisoprene: 10(18); (g) styrene and 20% styrenebutadiene styrene block copolymer: 10 (21); and (h) 40% styrene-butadiene block copolymer and styrene: 10 (20). In these examples the active sites on the polymer backbone are formed by using an organometallic catalyst formed from see-butyllithium and tetraethylene diamine whilst the hydrogenation catalyst comprises a mixture of cobalt octoate and triethyl aluminium. Fully hydrogenated graft copolymers are formed from (i) styrene and 1,4-polybutadiene and 3 (26), 7 (22, 23, 29), 10 (24, 27, 28); and (j) styrene and 63% 1,2-polybutadiene: 7 (25), in which the grafting sites are formed as in Examples 1 to 22 but using the hydrogen catalyst under a greater pressure and elevated temperature in an autoclave.