the data on the effect of ethylene concentration on polymerization rate for several modifications of modern highly active titanium–magnesium catalysts ticl4/mgcl2 are presented. these catalysts differ in titanium content and conditions of support preparation, activities, and the shape of kinetic curves. it is found that the observed order of polymerization rate with respect to ethylene in the r...

atom transfer radical polymerization of styrene (st) and methyl methacrylate (mma) was performed at 90oc in the absence and presence of nanoclay (cloisite 30b). trichloromethyl-terminated poly(vinyl acetate) telomerand cucl/ pmdeta were used as a macroinitiator and catalyst system, respectively. the experimental results showed that the atom transfer radical polymerization of st and mma in the a...

Graft polymerization of acrylic acid (AA) and ethyl methacrylate (EMA) onto starch (St) were carried out in aqueous solution using ceric ammonium nitrate (CAN) as redox system under N2 atmosphere. The effect of pH, reaction time, temperature, concentrations of CAN, St, and monomers on the graft yield was investigated. Monomer reactivity was in the following order: AA>EMA.<em...

A new potassium persulfate redox system has been investigated for the graft polymerization of vinyl monomers. In this study potassium persulfate system was used for initiation the polymerization. Graft polymerization of acrylonitrile (AN) onto starch (Sta) was carried out in aqueous solution using potassium persulfate (I) redox system. It was found that the percentage of grafting and rate of gr...

Objective(s): Crocin, as the main carotenoid of saffron, has shown anti-tumor activity both in vitro and in vivo. Crocin might interact with cellular proteins and modulate their functions, but the exact target of this carotenoid and the other compounds of the saffron have not been discovered yet. Microtubular proteins, as one of the most important proteins inside the cells, have several functio...

cellulose was modified by polystyrene (ps) and polyacrylonitrile (pan) via free radical and living radical polymerization, and then cellulose was used as the matrix in the preparation of polymer/clay nanocomposite, through a solution intercalation method. for this purpose, first, the graft polymerization of styrene (st) onto cellulose fibers was performed by using suspension polymerization and ...

a new model based on a combination of the polymeric multigrain and multilayer models has been developed to predict the polymerization rate, particle growth, morphology, effective parameters on broadening of the molecular weight distribution, number and weight average of the molecular weight, isotacticity index and bulk density of polymer. mathematical correlations and the kinetics used in this ...

objective(s): crocin, as the main carotenoid of saffron, has shown anti-tumor activity both in vitro and in vivo. crocin might interact with cellular proteins and modulate their functions, but the exact target of this carotenoid and the other compounds of the saffron have not been discovered yet. microtubular proteins, as one of the most important proteins inside the cells, have several functio...

In this article several control schemes for a pilot scale polymerization reactor are proposed and one of them is selected as the most suitable design. The performances of proposed schemes have been compared through computer simulations. The controllers are PID and Chosen reaction is polymerization of methyl methacrylate which is highly exothermic.

INTRODUCTION Polymer/clay nanocomposites, in which nanosized silicate plates of clay are uniformly dispersed in the polymer matrix, provide enhanced mechanical and thermal properties compared to conventional composites. Not all polymer and clay combinations will form nanocomposites: the compatibility and interfacial properties between polymer matrix and clay layers significantly influence the e...