Samaneh Ashenagar - Iran Polymer and Petrochemical Institute,P.O.Box14965/115,Tehran ,Iran.
Farshid Ziaee - Iran Polymer and Petrochemical Institute,P.O.Box14965/115,Tehran ,Iran.
Seyed Mehrdad Jalilian - Iran Polymer and Petrochemical Institute,P.O.Box14965/115,Tehran ,Iran.

On-line 1H NMR kinetic experiments have been successfully used for the kinetic study of free radical polymerization. The quantitative in situ NMR analysis is a new methodologywhich is described for the determination of the reactivity ratios [l]. On-line 1H NMR experiments let us to calculateindividual and overall monomer conversions at the same time,as well as the comonomer mixture and copolymer chain compositions as a function of reaction progress. This is one ofthe advantages of on-line 1H NMR technique in comparison with the off-line techniques [2, 3]. This paper presents studieson the copolymerization reactions of methacrylic acid (MAA) and ethyl acrylate (EA).