Functionalized copolymers. Methyl methacrylate-(4-hexyloxy-1-phenyloxycarbonyl)-1,4-phenylene ethylene copolymers: Synthesis, monomer reactivity ratios, thermal stability and solubility

The synthesis and monomer reactivity ratios between methyl methacrylate and (4-hexyloxy-1-phenyloxycarbonyl)-1,4-phenylene-ethylene, a liquid-crystal monomer, were performed. Different starting monomer compositions were used to obtain copolymers with various compositions. Reactivity ratios r₁ and r₂ were estimated by the classical Fineman Ross and Kelen-Tüdos linear procedures and a non-linear method. These parameters were also estimated by using a computer program based on a non-linear minimization algorithm starting from the r₁ and r₂ values obtained by the above linear procedures. Copolymers were obtained by radical polymerization in THF solutions at 323 K under vacuum. Linear representation of the polymerization data seems to indicate a random copolymerization with some tendency to blocks formation. The thermal decomposition temperatures of the copolymers were determined by thermogravimetric analysis. The kinetic parameters associated with the decomposition process, show that there are a decrease of the thermal stability of the copolymers relative to the homopolymers.