Copolymers bearing both epoxy and cyclopropane groups were synthesized by free-radical copolymerization of glycidyl 2- (4- vinylphenyl) cyclopropanecarboxylate (GVPCC) with methyl methacrylate (MMA) using AIBN at 343 K, in bulk and in benzene under inert atmosphere. Copolymer compositions were determined by spectroscopy, and copolymerization parameters were evaluated by the Fineman-Ross method. The reactivity ratios were r₁ (GVPCC) = 0. 68 ± 0. 05 and r₂ (MMA) = 0. 51 ± 0. 07; their product (r₁ ∙ r₂ = 0. 35) indicates random copolymerization with a tendency toward alternation. Alfrey-Price parameters (Q₁ = 0. 96, e₁ = −0. 63; q₂ = 0. 74, e₂ = 0. 40) confirm strong comonomer interactions and pronounced polar effects. For a 50/50 copolymer, the intrinsic viscosity was 0. 66 dL g^-1 (benzene, 25°C). Thermogravimetric analysis showed composition-dependent stability with T5 = 250-320°C, increasing with GVPCC content, alongside improved adhesion (up to 5. 6 MPa) and Vicat softening temperature (121°C). UV irradiation produced efficient crosslinking and negative-tone photoresist behavior (resolution with depth of penetration, Dp = 0. 25-0. 35 μm; critical exposure energy, Ec = 14. 5- 16. 4 mJ cm^-2 ; sensitivity, S = 61-69 cm^2 J^-1), demonstrating potential for UV-patternable microfabrication materials.
Vahabova et al. (Thu,) studied this question.