Kinetics and Modelling of Bulk and Solution Diallyl Terephthalate Polymerization

Free radical polymerization kinetics of diallyl terephthalate (DAT) in solution was investigated with two different peroxide initiators: dicyclohexyl peroxydicarbonate (CHPC) and benzoyl peroxide (BPO) in temperature range from 50°C to 110°C, where ortho-xylene was used as a solvent. Conversion points were measured using Fourier Transform Infrared (FTIR) measurements. Previously developed kinetic model for bulk DAT polymerization, was extended to solution DAT polymerization. The ratio of solvent chain - transfer rate constants to propagation rate constants of the polymerization system were found between 1.25 10-4 to 1.68 10-4 for various reaction conditions. They were obtained using the calculated initial polymerization rates and the number average molecular weight measurements made by GPC. The effect of different solvent fractions and initiator concentrations on the diffusion limitations were investigated. Only two kinetic parameters, kpd0 and ktd0 were obtained by fitting the kinetic model onto measured conversions for various reaction conditions at 0.2, 0.5 and 0.8 solvent fractions. Thus obtained kpd0 and ktd0 kinetic parameters were extrapolated to zero solvent fractions and from obtained values of kinetic parameters the conversion points for bulk DAT polymerization were calculated and compared to measured conversion points.

Comparison of two algorithms for calculation of the apparent rate constant in the kinetic modelling of diallyl terephthalate bulk polymerization

In the present study a comparison was made of two most frequently used algorithms for calculation of the apparent rate constant in the kinetic modelling of bulk cross-linking diallyl terephthalate (DAT) polymerization with four different peroxide initiators, bis(4-tert-butylcyclohexyl) peroxydicarbonate, dicyclohexyl peroxydicarbonate, benzoyl peroxide and dicumyl peroxide, in the temperature range from 50 to 150°C and at three different initiator loadings. The first algorithm is the CCS algorithm developed by Chiu, Carratt and Soong and the second is the S algorithm developed by Smoluchowski. Only two kinetic parameters had to be found by fitting a previously proposed kinetic model for bulk DAT polymerization, developed by Hace et al., to measured conversion points. Conversions and other necessary physico-chemical properties used for kinetic modelling were obtained from our previous kinetic studies on DAT polymerization.

Polymérisation du chloroformiate de vinyle et de ses dérivés

The free-radical polymerization of vinyl chloroformate has been studied in methylene chloride at 35 °C using dicyclohexyl peroxydicarbonate as initiator. Kinetic measurements performed by dilatometry under high vacuum have shown that the reaction order in monomer is equal to one whereas that in catalyst is equal to 0.5.New polymers have been prepared either by free-radical polymerization of monomers derived from vinyl chloroformate or by chemical modification of poly(vinyl chloroformate) with amines, alcohols, thiols, carboxylic acids, KCN … using phase transfer catalysis. The structure of these polymers as well as their thermal behaviour have been studied.