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Cationic polymerization catalyzed by boron trifluoride‐ether complexes. Vinyl polymerization. LI.

1961; Wiley; Volume: 48; Issue: 1 Linguagem: Inglês

10.1002/macp.1961.020480108

0025-116X

Minoru Imoto, Shuzo Aoki,

Inorganic and Organometallic Chemistry

Abstract The polymerizations of styrene and n ‐butyl vinyl ether catalyzed by BF 3 · ethyl ether or BF 3 · tetrahydrofuran complexes were carried out dilatometrically in benzene at 30°C. In the case of BF 3 · ethyl ether, the polymerization of styrene proceeded smoothly and the overall rate constant (k) was computed as 0.17 (mole/1.) −2 /min., according to the equation of R p = k[M] 2 [C]. BF 3 · tetrahydrofuran, however, did not initiate the polymerization of styrene. Therefore, it was concluded that C 2 H 5 + ‐cation from BF 3 ·O(C 2 H 5 ) 2 initiated the polymerization of styrene, but BF 3 · tetrahydrofuran did not produce any effective cation to initiate the polymerization. The polymerization of n ‐butyl vinyl ether catalyzed by both complexes proceeded rapidly and the rates of polymerization were expressed as follows: where x is 4.75 for BF 3 ·ethyl ether and 3.25 for BF 3 ·tetrahydrofuran. It was assumed that BF 3 ·tetrahydrofuran reacted with n ‐butyl vinyl ether to give C 4 H 9 + ‐cation which initiated the polymerization.