Synthesis of multisegmented block copolymer by Friedel-Crafts hydroxyalkylation polymerization

Multisegmented block copolymers (MSBCPs) were synthesized by acid-catalyzed Friedel-Crafts (F-C) hydroxyalkylation polymerization in a two-step process from a feedstock of commercially available or easily synthesized benzaldehyde (BA) derivatives and 1,4-dimethoxy benzene (DMB). Polymerizations of DMB with various BA monomers afforded a library of triarylmethane-backboned oligomers with nitro, fluoro, alkyl ester, dimethylamino and tert-butyl pendant functional groups. Using these oligomers as macromonomers in a subsequent F-C hydroxyalkylation polymerization under the same setup produced MSBCPs with tunable compositions of segments and high number-average molar mass similar to 10(5) g mol(-1). Glass transition temperatures (T-g) measured for the oligomers and MSBCP became tunable between 121.3 degrees C and 227.7 degrees C. Meanwhile, water contact angle measurements of the spin-coated membranes were compared and a pH-responsive MSBCP was synthesized to demonstrate switchable surface wettability and polarity.