| 摘要 |
1517774 Butadiene/piperylene copolymers EXXON RESEARCH & ENG CO 19 June 1975 [22 July 1974] 26108/75 Heading C3P A copolymer of 1,3-butadiene and piperylene is characterized by (a) a random distribution of monomer units in the polymer chain, (b) vinyl unsaturation pendant to the main polymer chain which is present in any amount up to 10% of the total unsaturation present in the polymer, (c) enchainment of at least 95% of the piperylene monomer units in a 1,2-trans- and 1,4-trans-stereoisomeric configuration and (d) the selective enchainment of between 50 and 95% of the butadiene monomer units in the 1,4- trans-stereoisomeric configuration. These copolymers may be prepared using a catalyst system comprising TiXn-xMIn-yI2-zAIR3- QLB where X = Cl, Br or I; M is a Group IIIa or IVa metal (Mendeleeff's Periodic Table), R = C1-C12 alkyl, aryl, alkylaryl and cycloalkyl; LB is a Lewis Base; n = 2-4, x = 0- 20, y = 0-5, z = 1-40, Q = 5-500. Preferably TiXn is TiCl3 and MIn is AlI3. Preferred Lewis Bases are thia and oxa heterocyclics, e.g. thiolanes such as tetrahydrothiophene, alkyl thiolanes such as 3-methyl tetrahydrothiophene, tetrahydrofuran, alkyl tetrahydrofurans such as 2,5-dimethyl tetrahydrofuran, and tetrahydrothiapyrans, tetrahydropyrans and alkyl derivatives thereof. In the examples catalyst systems comprising TiCl4, TiCl3, TiBr4, TiI4, TiI2, SnI4, AlI3, AlEt3, I2, and tetrahydrothiophene are used in various solution polymerizations of butadiene and piperylene.
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