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Cationic Polymerization of Cyclic Dienes. IV. Polymerizations of Cyclopentadiene with Stannic Chloride-Trichloroacetic Acid and Borontrifluoride Etherate

1968; Marcel Dekker; Volume: 2; Issue: 3 Linguagem: Inglês

10.1080/10601326808051425

2332-4082

Yukio Imanishi, Shinzo Kohjiya, Seizô Okamura,

Polymer Nanocomposites and Properties

Abstract Cyclopentadiene has been polymerized with SnCl4-CCl3CO2H or BF3-O(C2H5)2 in toluene solution at -78°C. In the polymerization induced by SnCl4-CCl3CO2H, it was found that two different types of polymerizations coexisted. At first the polymerization was very rapid and of nonstationary state, but toward the end it was slow and of stationary state. As the majority of monomers initially present was consumed during the nonstationary-state polymerization, intrinsic viscosities of resultant polymer showed the behavior characteristic of nonstationary-state polymerization, such as (I) they decreased with increasing catalyst concentration, and (2) they were affected very little by the water concentration. The polymerization induced by BF3-O(C2H5)2 was much slower than that by SnCl4-CCl3CO3H, but it was found to be of nonstationary state. However, it was nearly stationary-state polymerization, except for the very beginning of the polymerization. This was reflected in the behavior of polymer intrinsic viscosities-such as (1) they were unaffected by the catalyst concentration, and (2) they were lowered with increasing the water concentration. Taking into account these experimental findings as well as those found in the polymerization by TiCl4-CCl3CO2H, a tentative mechanism was proposed for the initiation reaction of cyclopentadiene polymerization, in which a reaction order among a monomer, a catalyst, and a cocatalyst is important in determining the mechanism.