New strategies for synthesis of amino-functionalized poly(propylene carbonate) over SalenCo(III)Cl catalyst

New strategies for synthesis of amino-functionalized poly(propylene carbonate) (PPC) were applied by terpolymerization of carbon dioxide, propylene oxide, with (a) N-(2,3-epoxypropyl)-2-phthalimide (Monomer A)/N-(2-oxiranylmethyl)-1 or (b) N-(2-oxiranylmethyl)-1,1-dimethylethyl ester (Monomer B) over SalenCo((III))Cl/PPNCl catalysts system, followed by the removal of the respective protecting groups. The SalenCo((III))Cl presented high activity and yielded the terpolymer with high polycarbonate selectivity, carbonate linkage content, as well as high head-to-tail stereoregularity (>99%). In terpolymerization, the Monomer A contents in PPC-Pht were easily regulated up to 12.0 mol%. However, the protecting groups could not be completely removed because of the degradation of PPC-NH2-A during the deprotection process. Meanwhile, when terpolymerization with Monomer B, PPC-butoxy carbonyl was obtained varied the Monomer B contents from 1.3 to 4.5 mol%, and could be transformed completely into the amino-functionalized PPC-NH2-B without significant backbone degradation. The contact angles of the functionalized PPC-NH(2)s prepared by two strategies showed the expected increase in hydrophilicity with the increasing content of amino entities.