New information on the alternating copolymerization of butadiene‐1,3 with acrylonitrile

Abstract

Butadiene‐1,3 and acrylonitrile were copolymerized by alkylaluminum halides alone or, more effectively, by the alkylaluminum halide/vanadium compound systems, into an alternating copolymer in which the butadiene units are linked predominantly in the trans‐1,4 configuration. The efficiency of the aluminum components in the latter catalyst systems appear to decrease in the following order: AlEtCl2 > Al2Et3Cl3 ≫ AlEt2Cl(≫AlCl3). The alkylaluminum halides could also be used effectually in the form of the complex with acrylonitrile. The catalytic activity was markedly affected by the order of mixing of the catalyst components and the monomers. Effective catalysts could be prepared only when the catalyst components were mixed in the presence of acrylonitrile. The catalyst activity was also found to depend upon the Al/V ratio, reaching its maximum when the ratio was about 20 in the AlEtCl2·AN/VO(Ot‐Bu)3 system. Other combinations of conjugated diene with conjugated polar vinyl monomer were similarly copolymerized by these catalysts. It was found that different feed ratios between the diene and the vinyl monomer which were varied over a wide range always resulted in the formation of a 1:1 copolymer. The butadiene‐acrylonitrile copolymer thus formed gave an NMR spectrum in which there was only one peak assignable to the methylene protons (7.72 τ) of the butadiene unit. On the basis of these findings, it may be suggested that alternating copolymerization prevails in the polymerization systems here investigated.

Alternating Copolymerization of Butadiene and Acrylic Compounds

“…4 It is likely that the formation of the Al-MMA-BD complex occurs more readily than that of the Al-AN-BD complex.…”

Mechanism of alternating copolymerization of acrylic monomers with donor monomers in the presence of lewis acid

“…Conventional chain-transfer solvents such as carbon tetrachloride or chloroform hardly affect the molecular weight of the alternating copolymer which incorporates no chlorine (Furukawa et al, 1970a;Gaylord and Antropiusova, 1969;Hirooka et al, 1973).…”

“…The terpolymerization of two acceptor monomers and one donor monomer or of one acceptor monomer and two donor monomers, in the presence of a metal halide, produces terpolymers containing always equimolar amounts of the sum of acceptor monomers and the sum of donor monomers, irrespective of the charged monomer ratio. For example, the AIEtClz-VOCl3-methyl methacrylate-acrylonitrile-butadiene (MMA:AN:BD = 1 :1:4) system yields the terpolymer composed of monomer unit in a MMA:AN:BD molar ratio of 39:12:49; the AlEtClz-VOCl~-methyl methacrylate-styrene-butadiene (MMA :ST :BD = 1:2:4) system does that in a MMA:St:BD molar ratio of 49:12: 40 (Furukawa et al, 1970a); the AIEt1.sC11.5-methyl acrylate-acrylonitrile-styrene (MA:AN:St = 1 :9:10) system does that in a MA:AN:St molar ratio of 20.0:31.8:48.2 (Hirooka et al, 1973).…”

Polymerization of coordinated monomers. XVI. Stereoregulation in the alternating copolymerization of methyl methacrylate with styrene in the presence of metal halides

“…On the other hand, Bernoullian statistics has been applied exclusively to the stereosequence distribution, for example, of the copolymerizations of methyl methacrylate-styrene* and vinyl chloride-pr~pene.~ Polar vinyl monomers such as methyl methacrylate and acrylonitrile are known to copolymerize alternately with electron-donating monomers such as styrene and dienes in the presence of metal halides such as zinc chloride and ethylaluminium sesquichloride. [6][7][8][9][10] The cotacticity of the alternating copolymer of methyl methacrylate with styrene was determined by the present authorll using lH-NMR. The cotacticity distribution was found to depend on the kind of metal halides and could not be explained by a single c parameter of the probability of isotactic dyad addition between the comonomer.…”