Study on whole-conjugated polymer gel. Synthesis of polybenzal gel with benzal chloride and toluene

Polybenzal (m-directing) gels were synthesized with benzal chloride (BC, monomer and crosslinking agent), toluene (monomer), and anhydrous aluminium chloride (catalyst) in nitrobenzene at 90°C by the Friedel-Crafts alkylation. The colour of the product changed from brown to black as the toluene content decreased. The swelling of the product gel in tetrahydrofuran was slight or none. No gelation occurred in the case of the molar ratio of toluene/BC above 0.75. Considering the above results, i.r. spectra, visible spectra, and composition of the products, the polymer gels obtained had many long conjugated systems.