Three-dimensional copolymerization of methyl methacrylate and allyl methacrylate in the presence of aromatic polyimide

Crosslinked copolymers capable of swelling in organic solvents were synthesized by the free-radical copolymerization of methyl methacrylate and 2-10 wt % allyl methacrylate in the presence of polyimide (4 wt %, η inh = 0.38-1.02 dl/g), soluble in the starting reaction mixture, and without polyimide. Using isothermal calorimetry at 70°C, it was shown that, as the concentration of a crosslinking agent increases, conversions that correspond to the onset of autoacceleration and autoretardation and the intensity of the gel effect decrease. It was demonstrated that the addition of an aromatic polyimide to the system also influences the parameters of the gel effect in copolymerization and the homogeneity of the resulting polymer samples. Swelling of the polymer systems of interest in chloroform and toluene was studied, and the parameters of their network structure were determined. It was found that the thermal stability of PMMA was enhanced upon the addition of aromatic polyimide. When the amount of allyl methacrylate was reduced to 2 wt %, the compressive and flexural strength and moduli of the resulting polymers increased.