Transformations of chloroethylenes in the presence of aprotonic acids

✍ Scribed by Zilberman, E. N. ;Kulikova, A. E. ;Pinchuk, N. M. ;Taikova, N. K. ;Okladnov, N. A.

• Publisher: Wiley (John Wiley & Sons)
• Year: 1970
• Tongue: English
• Weight: 659 KB
• Volume: 8
• Category: Article
• ISSN: 0449-296X
• DOI: 10.1002/pol.1970.150080902

✦ Synopsis

Abstract

The cationic polymerization of vinyl chloride, vinylidene chloride, and cis‐ and trans‐ 1,2‐dichloroethylenes with the use of Lewis acid‐type catalysts has been studied. Vinylidene chloride is smoothly polymerized in the presence of ZnCl~2~ at 40°C to form the dimer, 1,1,3,3‐tetrachlorobutene‐1, and poly(vinylidene chloride) having somewhat increased crystallinity (45%). Vinyl chloride is polymerized very slowly in the presence of AlCl~3~ and TiCl~4~ to give dimeric, trimeric, tetrameric, and low molecular weight polymer products. The polymerization is followed by carbonium ion isomerization that leads to reaction products of branched structure. The cis‐ and trans‐1,2‐dichloroethylenes react in the presence of AlCl~3~ only at 50–60°C, and their polymerization is terminated at the stage of dimer and cyclic trimer formation. A mechanism of carbonium ion‐initiated polymerization of chloroethylenes is proposed, and the causes which lead to early termination of polymerization are discussed.