Investigations on the kinetics of copolymerization of vinyl acetate with acrylonitrile by Co(acac)₃–Al(C₂H₅)₃ catalyst system

Abstract

Vinyl acetate and acrylonitrile were copolymerized with Co(acac)3‐Al(C2H5)3 catalyst system in benzene at 40°C. The rate of copolymerization is linearly proportional to monomer concentration and catalyst concentrations up to a certain value. The overall activation energy was found to be 11.3 kcal/mole. The effect of hydroquinone on the rate of copolymerization indicates the presence of free radicals in this system. The possibility of simultaneous formation of coordinate anionic and free radical active sites has been proposed.

A Kinetic Investigation of the Copolymerization of Acrylonitrile and Vinyl Acetate in Bulk

“…They examined the kinetics of the system and the composition of products. Similarities to the AIBN initiated polymerization were observed suggesting that anionic and radical propagation were concurrent in the system [21]. This was confinned by a decrease of the rate in the presence of radical inhibitors.…”

“…The use of ZieglerNatta type catalysts has also been examined. Sharma et al [21] have studied ANNAc copolymerization in the presence of Co(AcAc),/AlF!h. They examined the kinetics of the system and the composition of products.…”

Optimization of Ceric Ammonium Nitrate Initiated Graft Copolymerization of Acrylonitrile onto Chitosan

“…As a result, the maximum yield has been found at 55 min. Hence 55 min was found to be rate of grafting [20,21]. Figure 2 shows the effect of concentration of CAN on the graft copolymerization of polyacrylonitrile onto chitosan by keeping other reaction conditions constant.…”

Investigation of kinetics of 4‐methylpentene‐1 polymerization using Ziegler–Natta‐type catalysts

“…The ratio exhibiting maximum activity in the present study is in agreement with the postulations of the formation of stoichiometric homogeneous complexes in solution. 21,26 The decrease in the molecular weights of polymers at a higher molar ratio indicates that the triethyl aluminum acts as a chain transfer reagent with the complex formed. 25a The kinetic dependence of the polymerization rate on the triethyl aluminum concentration has been derived to be in the range of 0.5-1.0, which is explained by the shifting of the equilibrium to the right in the deduced mechanism.…”

“…The molecular weights of the polymers with all the catalyst systems studied increased with time (Table I), similar to high-activity catalyst systems. This effect is characteristic of homogeneous [21][22][23] catalyst systems, which has been attributed to the decrease in the concentration of active centers present in the catalyst systems.…”