Copolymerization of Acrylonitrile with Some Allyl Monomers: Characterization and Determination of Reactivity Ratios

S.Najim, Tariq

	Copolymerization of Acrylonitrile with Some Allyl Monomers: Characterization and Determination of Reactivity Ratios
Al-Mustansiriyah Journal of Science
Article 1, Volume 21, Issue 5, 2010, Pages 183-194
Author
Tariq S.Najim
Abstract
Free radical copolymerization of acrylonitrile (AN) with allyl alcohol (AA), allyl benzoate (AB) and allyl chloride (AC) were carried out at 60oC in Bulk . Azobisisobutyronitrile (AIBN) was used as an initiator. The conversion of the monomers to polymers at different intervals were carried out under the same conditions so as to maintain the conversion below 10%. Free radical homopolymerizations of AN, AA, AB and AC ware also performed using AIBN as initiator under the same conditions. Fourier transform infra-red (FTIR) and normal infra-red (IR) spectroscopy were used to evaluate the concentration of each monomer in the prepared copolymers using the absorption bands of a chosen group in each monomer which are (-C≡N) in acrylonitrile , (-OH) in allyl alcohol, (C=O) in allyl benzoate and (-C-Cl) in allyl chloride . Monomer reactivity ratios (r1 and r2) for AN, AA, AB and AC have been calculated utilizing Fineman-Ross (F-R) and Kelen-Tudos (K-T)equations, Microsoft quick basic program has also been used for estimating some of reactivity ratios. Reactivity ratios for AN, AA and AC monomers have also been calculated theoretically by using (Q-e) scheme of Alfrey-Price. In all cases, there were a good agreement between theoretical and experimental values of reactivity ratios and that found in literature. Q and e values of allyl benzoate in poly(AN-co-AB) were calculated from its reactivity ratio values. Depending on the multiplying result of r1 and r2, the prepared copolymers were random and getting close to alternative according to the product (r1r2) for each system and each copolymer system were rich in acrylonitrile monomer units, due to the stabilization by conjugation of maromolecular radical of allyl monomers,as well as, its participation in chain transfer reactions. The composition of each copolymer was evaluated by plotting the mole fraction of AN monomer in feed and in the copolymer.

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