Production of Unsaturated Graft Copolymers from Isobutylene Polymers

1,154,699. Grafted isobutylene polymers. BADISCHE ANILIN- & SODA-FABRIK A.G. 21 Oct., 1966 [23 Oct., 1965], No. 47232/66. Heading C3G. A 1,3-diene is grafted on to the reaction product of a halogenated isobutylene polymer with a Lewis acid. The diene is e.g. butadiene, isoprene or chloroprene; a mixture of a diene with styrene, α-methyl styrene or a vinyl ether such as ethyl, n-propyl, isobutyl or n-hexyl vinyl ether may be used. The isobutylene polymer, which is a homopolymer, or a copolymer of at least 80% isobutylene with butadiene, isoprene, styrene, α-methyl styrene or a vinyl ether, is halogenated conventionally. A list is given of suitable Lewis acids and of Ziegler- Natta catalysts which may be used for the polymerization. The graft polymers may he vulcanized with conventional agents and then compounded with fillers. In Examples 1 and 2 a brominated polyisobutylene is dissolved in toluene and reacted with AlCl 3 prior to grafting with butadiene and isoprene respectively, using Et 3 AlCl and cobalt (II) acetylacetonate as catalyst. Examples 3 to 18 describe processes in which a chlorinated isobutylene-isoprene rubber is dissolved in an n-hexane/toluene mixture and reacted with TiCl 4 , ZrOCl 2 , TiBr 4 , TiI 4 , AlBr 3 , HClO 4 , SnCl 4 , NbCl 5 , TaCl 5 , VCl 4 , MoCl 4 , palladium (II) hydrochloride, gold (III) hydrochloride, platinum (IV) hydrochloride or FeCl 3 and grafted with butadiene using AlEt 3 and cobalt (II) acetylacetonate as catalyst. In Example 19 a brominated isobutyleneisoprene rubber is dissolved in a p-diisopropyl benzene/pentane mixture and grafted with butadiene using AlBr 3 as the Lewis acid and AlEt 3 and chromium (III) acetyl acetonate as catalyst.