Study of the molar mass of grafted polystyrene onto cellulose by the probability indices optimization

Abstract

UkraineGraft polymerization of styrene onto cellulose was investigated using ceric ions redox systems as initiator. The effects of reactant concentrations and of processing variables on the molar mass of grafted styrene on the cellulose were studied. A statistical model with the D-optimal design was used to describe the system. The optimum polystyrene molar mass obtained by simulation was compared to experimental data. The optimal reaction conditions for such a reaction were determined.La polymerisation par greffage du styrene sur la cellulose a ete effectuee en presence d'ions cerique (IV). On a etudie I'effet de la concentration des reactifs (amorceur, cellulose, monomere) ainsi que les variables d'operation (agitation, temperature, temps de reaction). Un modele statistique a ete utilise pour obtenir les conditions optimales du procede. Les valeurs optimales pour la masse molaire ont ete determinees experimentalement et par simulations. Les conditions experimentales optimales ont ete determinees.Keywords: graft, polymerization, molar mass, cellulose, styrene, modelling.ellulose and its derivatives, particularly grafted cellu-C lose, has generated a great interest in the production of composites (Hebeish and Guthrie, 1981). The addition of certain copolymers to the composite alters the interfacial adhesion between phases. These copolymers will act as a compatibilizer by reducing the interfacial tension and by improving the adhesion between the components of the composite (Paul, 1978).Researchers have noted that compatibilizing effects will appear when the molar mass of homopolymers forming the composite is less or, at least, comparable to the molar mass of grafted polymers. In the case when the molar mass of the homopolymers in the composite is greater than the molar mass of the graft, the homopolymers will form separate phases and will not blend with the copolymer part (Locke and Molau, 1970).Taking in account these peculiarities the system was optimized for the molar mass. Experimental procedureIn the present case, the free-radical polymerization mechanism with cerium IV as initiator was selected for studying cellulose/styrene copolymerization (Mino et al., 1959; Graczyk and Hornoff, 1988 a, b). The reaction was conducted under a nitrogen blanket essentially the same as was described elsewhere (Bataille et al., 1996).The effects of six variables on the copolymer yield (apparent and true) and polymer conversion were established. Low and high levels of factors variation were selected after taking into account the experimental data obtained from previous investigations (Bataille et al., 1996; Bataille *Authortowhomcorrespondenceshwldbeaddressed. Fax: (514)34M159.et Statiukha, 1995; Graczyk and Homoff, 1983; Graczyk and Homoff, 1988).The following criteria were selected to characterize the process: Y, -grafting yield, Y,-true grafting yield, Yj-conversion of the monomer to polymer and Y4-conversion of monomer to grafted polymer.The grafting yield, G, is the mass ratio of grafted polymer to cellulose. where A is t...

Copolumers obtained by grafting of vinyl monomers on starch - influence of amines on synthesis and degradation processes in environment

“…Reakcija kalemljenja se odvijala u benzenu, a korišćeno je UV zračenje u opsegu od 310-460 nm. Kalemljeni kopolimeri se mogu dobiti i korišćenjem Ce 4+ jona kao inicijatora u atmosferi azota [141]. PS je, takoĎe, kalemljen na etil-celulozu [142,143].…”