title: Low temperature aqueous living/controlled (RAFT) polymerization of carboxybetaine methacrylamide up to high molecular weights.
abstract: Among the class of zwitterionic polymers poly(carboxybetaine)s (poly(CB)s) are unique, emerging as the only ultra-low fouling materials known allowing the preparation of biosensors, fouling resistant nanoparticles, and non-adhesive surfaces for bacteria. Poly(carboxybetaine methacrylate) and poly(carboxybetaine acrylamide) have been prepared via atom transfer radical polymerization (ATRP), however a polymerization with living characteristics has not been achieved yet. Herein, the first successful living/controlled reversible addition fragmentation transfer (RAFT) polymerization of (3-methacryloylamino-propyl)-(2-carboxy-ethyl)-dimethyl-ammonium (carboxybetaine methacrylamide) (CBMAA-3) in acetate buffer (pH 5.2) at 70 and 37 °C is reported. The polymerization afforded very high molecular weight polymers (determined by absolute size exclusion chromatography, close to 250,000 g·mol(-1) in less than 6 h) with low PDI (<1.3) at 70 °C. The polymerization was additionally carried out at 37 °C allowing to achieve yet lower PDIs (1.06 ≤ PDI ≤ 1.15) even at 90% conversion, demonstrating the suitability of the polymerization conditions for bioconjugate grafting. The living character of the polymerization is additionally evidenced by chain extending poly(CBMAA-3) at 70 and 37 °C. Block copolymerization from biologically relevant poly[N-(2-hydroxypropyl)methacrylamide] macroCTAs was additionally performed.
authors.affiliation: Institute of Macromolecular Chemistry AS CR, Heyrovskeho Sq. 2, Prague 6, 162 06, Czech Republic. rodriguez@imc.cas.cz
authors.forename: Cesar
authors.initials: C
authors.lastname: Rodriguez-Emmenegger
authors.forename: Bernhard V K J
authors.initials: BV
authors.lastname: Schmidt
authors.forename: Zdenka
authors.initials: Z
authors.lastname: Sedlakova
authors.forename: Vladimir
authors.initials: V
authors.lastname: Šubr
authors.forename: Aldo Bologna
authors.initials: AB
authors.lastname: Alles
authors.forename: Eduard
authors.initials: E
authors.lastname: Brynda
authors.forename: Christopher
authors.initials: C
authors.lastname: Barner-Kowollik
mesh_terms: D000178:Acrylamides / Q000138:chemical synthesis* / Q000737:chemistry*; D002625:Chemistry, Organic / Q000379:methods*; D008970:Molecular Weight; D058105:Polymerization; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry; D013696:Temperature
chemical_list: D000178:Acrylamides; D011108:Polymers; C533866:poly(carboxybetaine acrylamide); C045985:methacrylamide