Abstract

RUEDA, Juan C et al. Synthesis of new block copolymers based on polyethylenglycol and 2-Oxazolines. Rev. Soc. Quím. Perú [online]. 2015, vol.81, n.4, pp.299-310. ISSN 1810-634X.

New block copolymers (typ AB) were obtained by the ring opening cationic polymerization of 2-cyclopropyl- and 2-methoxycarbonylethyl-2-oxazoline, using tosylated polyethylenglycol as initiator. In block copolymers, the polymerization grade of polyethylenglycol (PEG) segment was always 45 units and of the poly(2-oxazolines) segment was variable, between 33 to 242 units. The block copolymers, containing 2-methoxycarbonylethyl-2-oxazoline, were submitted to a quantitative hydrólisis of ester groups to obtain carboxylic acid units. The copolymers were characterized structurally by nuclear magnetic resonance spectroscopy and they show a conformational transition (LCST) between 24 and 48°C, which was function of the polymer structure, of its content of cyclopropyloxazoline and carboxilic acid groups.

Keywords : copolymers; poly(ethylenglycol; poly(2-oxazolines.

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