Synthèse de polystyrènes chlorométhylés renfermant des radicaux tétrathiafulvalène carbonyloxyméthyles

In order to solve the problem of polymer swelling, which limits the resolution for negative resists, new resists were developed which show no swelling. The undesirable swelling can be suppressed by converting nonpolar crosslinked polymers into polar ones, which are soluble after irradiation. This aim was attained by mixing a polystyrene bearing tetrathiafulvalenyl (TTF) groups with 1,2-dibromo-1,1,2,2-tetrachloroethane. For our study, we applied resists including poly(4-chloromethylstyrene)s containing tetrathiafulvalenecarbonyloxymethyl groups (1 and 2). Poly(4-chloromethylstyrene)s (4) or poly[styrene-co-(4-chloromethyl)styrene]s (5) with a variety of controlled molecular weights and molecular weight distributions were prepared by radical chain polymerization. The reaction of cesium tetrathiafulvalenecarboxylate (3) with 4 or 5 was carried out and the resultant substituted polymers 1 and 2 were characterized.