Synthesis, characterization and chemical degradation of poly(ester-triazole)s derived from d-galactose

RIVAS, M. VERóNICA; PETROSELLI, GABRIELA; ERRA-BALSELLS, ROSA; VARELA, OSCAR; KOLENDER, ADRIANA A.

RSC Advances

Royal Society of Chemistry

Lugar: Amsterdam; Año: 2019 vol. 9 p. 9860 - 9869

á-Azide-ù-alkynyl ester monomers were designed and synthesized in order to obtain hydrolytically degradable polymers. The monomers were prepared from d-galactose, as a renewable resource. Environmentally benign azido-alkyne cycloaddition polymerizations were conducted to afford poly(ester-triazole)s, with complete atom economy. Although polymer formation prevailed under optimized polymerization conditions, variable proportions of cyclic oligomer byproducts were detected. The Cu-catalyzed click polymerization led regioselectively to 1,4-disubstituted triazole linkages, while the thermal, metal-free polymerization produced a random distribution of 1,4- and 1,5-disubstituted triazoles in the polymer backbone. The poly(ester-triazole)s exhibited high molecular weights (M w in the range 35-85 kDa). They were soluble in organic solvents but highly insoluble in water, thus removal of the Cu(i) catalyst was simplified. The polymers were stable up to 300 °C, and had T g values in the range 90-100 °C. The materials were hydrolysed under either basic or strong acid conditions, and the degradation products have been characterized.