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EFFECTS OF ADDITION OF INORGANIC SALTS ON THE COPOL YMERIATION OF VINYL AND ALLYL MONOMERS

Khan, Abdul Rasheed (1980) EFFECTS OF ADDITION OF INORGANIC SALTS ON THE COPOL YMERIATION OF VINYL AND ALLYL MONOMERS. PhD thesis, University of Karachi, Karachi.

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Abstract

Studies on the rate of thermal copolymerization of viny1 and ally1 monomers in the presence of inorganic salts like copper chloride, cobalt chloride, cadmium chloride, mercury chloride, strontium chloride, manganese chloride, zinc chloride, nickel chloride, platonic chloride and chromium chloride have been carried out. As a general behavior, those salts which are soluble in monomer pair increase the rte by forming complexes through active monomeric group provided sufficient quantity of monomer is left behind to serve as a solvent for the complex formed. This is the reason for the monomer reactivity ratio not being changed appreciably. Our findings show a marked decrease in the number average molecular weight Mn of copolymer prepared in the presence of salt suggesting that salt behave as a chain transfer agent. It was also observed that the binary mixture of the monomers when heated in the presence of such salts which are insoluble in both monomers, the initiation reaction takes place thermally by the adsorption of the reacting monomers on the solid surface of inorganic salts. The overall mechanism may be that the initiation step of the radical copolymerization of viny1 and ally1 monomers in the absence of salt might be thermal initiation caused by the hydrogen transfer between the monomers. In the presence of salt monomers undergo complexation due to delocalization of II-electrons of the double bond of complexed monomer. The complexation of the monomers with salt probably increase the polarity of the monomers and stabilize the transition state of the reaction

Item Type:Thesis (PhD)
Uncontrolled Keywords:copol ymeriation, vinyl monomers, allyl monomers, copper chloride, cobalt chloride, cadmium chloride, mercury chloride, strontium chloride, manganese chloride, zinc chloride, nickel chloride, platonic chloride, chromium chloride, copolymerization
Subjects:Physical Sciences (f) > Chemistry(f2)
ID Code:852
Deposited By:Mr. Muhammad Asif
Deposited On:30 Oct 2006
Last Modified:04 Oct 2007 21:03

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