Allyl methacrylate was polymerized by gamma-radiation under vacuum in solution and atom transfer radical polymerization (ATRP) methods and also in the presence of atmospheric oxygen in bulk. The kinetic curve is S-type with a longer induction period, because of the presence of oxygen, in bulk polymerization. The curve for the solution polymerization is almost linear with a short induction period. The rate started to decrease after about 60% conversion and reached to a limiting conversion of 100%. The polymerization by ARTP method using gamma-radiation as initiator instead of conventional heating method gave a kinetic curve of linear character up to about limiting conversion of 100%. The polymers obtained were mostly gel type with linear chain fractions at lower conversions. The polymer characterizations were carried out by FTIR, differential scanning calorimetry, NMR, TGA, and XRD methods. The polymers were shown to proceed by the opening of vinyl groups. The allyl groups caused a limiting crosslinking, but 98-99% of the allyl groups are shown by FTIR and NMR, unchanged during the polymerization. The cyclic type polymer formation was not likely taking place. (c) 2007 Wiley Periodicals, Inc.