Estudo dos efeitos do iniciador n-Butil LÃtio, do agente de terminaÃÃo 1,2-Butadieno e da temperatura sobre a polimerizaÃÃo do 1,3-Butadieno em solvente apolar

AUTOR(ES)
DATA DE PUBLICAÇÃO

2003

RESUMO

The synthetic rubber production industries form one of the important sectors in petrochemical industry. The polibutadiene, one of the products originated from this sector, is the synthetic elastomer second-most produced worldwide. However, it has been notice that, regardless of the many papers already published about this subject, there are still many controversies regarding the influence of operational factors in the rate of reaction of this elastomer. In those investigations, it has not been identified models that predict the behavior of the properties of the end product, in face of the perturbations caused by many reactor input factors. This paper focused on the study of the effect of n-butyllithiumâs initial concentration. In addition, on the initial concentration of 1,2-butadiene and the reactional environmentâs temperature. Finally, on the structural configuration of the polymer, resulting from the polymerization of the 1,3-butadiene in a non-polar solvent medium. In order to achieve these objectives, this work adopted a Design of Experimental, whit two levels and three factors, having the three aforementioned factors varying as follows: (320.5 and 337.5) Ã 10-6 of initiator mol / 1,3-butadiene mol, (844 and 1012) Ã 10-6 of 1,2-butadiene mol / 1,3-butadiene mol and (138 to 140)oC. The dependent variables chosen for study were Mooney viscosity and viscosity in solution of the end product. This work also intended to propose a reactional mechanism, which would be able to interpret the experimental results obtained, as well as elaborate the kinetic model of the polymerization of the 1,3- butadiene. The experiments showed that the n-butyllithium is a factor of great significance regarding the parameters studied. Based on the experiments it was possible propose a statistical model that expressed the output variables related to the perturbation caused for each of the factors handled. The model showed correlation coefficient of 0.989 for viscosity Mooney and 0.974 for viscosity in solution. The proposition of the reactional mechanism presented for the elaboration of the reaction rate equation, obtained the experimental results, did not permit an evaluation of the kinetic parameters, due to the over dimensioning of the reactor employed, thus preventing a quantification by analysis of the residual monomer

ASSUNTO(S)

viscosity in solution 1,3-butadiene viscosidade mooney 1,3-butadieno engenharia quimica mooney viscosity viscosidade em soluÃÃo

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