Free-radical polymerization of methyl methacrylate in the presence of soluble poly(imide)

The AIBN-initiated free-radical polymerization of methyl methacrylate carri ed out at 70 degreesC in the presence of 1-15 wt % dissolved poly(imide) wa s studied by calorimetry. it was shown that, upon the addition of poly(imid e) (up to 10 wt %), the kinetic curves of polymerization demonstrate a shif t in the onset of autoacceleration and autoretardation to lower conversions compared to the polymerization of pure methyl methacrylate. When the conce ntration of poly(imide) reaches 15 wt %, no gel effect is observed due to t he existence of a strong diffusion control at all stages of the process. Ba sed on the experimental data on polymerization conducted in the presence of a model bis(imide), as well as on the thermal initiation of the above proc ess, it is inferred that poly(imide) macromolecules do not form additional polymerization sites but may take part in the reactions of chain transfer a nd (or) termination of growing poly(methyl methacrylate) macromolecules.