Aliphatic Polyesters by Bismuth Triflate-Catalyzed Polycondensations of Dicarboxylic Acids and Aliphatic Diols

Abstract

Polycondensations of aliphatic dicarboxylic acids (ADAs) with 1,4-butane or 1,6-hexane diol were conducted in bulk at 80 or 100 °C. Temperature and monomer/catalyst ratio were varied. With bismuth triflate, Bi(OTf) 3 , as catalyst, number average molecular weights (M n 's, uncorrected SEC data) up to 30 000 Da were obtained. Analogous polycondensations were performed with the triflates of sodium, magnesium, aluminum, zinc, tin(II), scandium, and hafnium, but the highest M n values were achieved with Bi(OTf) 3 . Polycondensations and model experiments proved that most triflates catalyzed the formation of tetrahydrofuran from 1,4-butane diol above 100 °C. Therefore, polycondensations of 1,4-butane diol required temperatures e100 °C. Polycondensations of 1,4-butene diol or 1,4-butyne diol were unsuccessful, because of side reactions. All polycondensations involved rapid equilibrations, and the content of cyclic oligo-and polyesters increased with the conversion.

Synthesis, Properties and Applications of Biodegradable Polymers Derived from Diols and Dicarboxylic Acids: From Polyesters to Poly(ester amide)s

“…Stannic components have also been studied for the synthesis of PBS in solution despite long reaction times being required [29]. The use of bismuth-based compounds for the synthesis of aliphatic polyesters has also been reported [30,31]. The efficiency of different catalyst has been just compared for PBS synthesis.…”

Bismuth‐Triflate‐Catalyzed Polymerizations of ε‐Caprolactone

“…In the case of La(OTf) 3 this result differs from the finding of Nomura et al,39 but the reaction conditions were quite different. The extremely low activity of Mg(OTf) 2 in the polymerization of εCL is paralleled by a similarly low activity in the polycondensations of aliphatic diols with dicarboxylic acids51 or their anhydrides 50. Of course, the esterification of carboxylic groups involves a mechanism which differs from that of transesterification.…”

Biotic and Abiotic Synthesis of Renewable Aliphatic Polyesters from Short Building Blocks Obtained from Biotechnology

“…Similarly,K richeldorf et al reported the successful use of bismuth compounds for the synthesis of aliphatic polyesters from dimethyl ester, [149] succinic anhydrides, [146] or from the direct polycondensation of dicarboxylic acids. [149,150] M n values of up to 30 000 gmol À1 were obtained from the bulk polymerization at 80 8Cf or over 48 h. Compared with scandium, bismuth is particularlyi nteresting because it combinest wo advantages:lower toxicity and ah igher efficiency as an esterification catalyst. [150] Moreover,these metal-based Lewis acid catalysts are particularly interesting for monomers containing vinyl groups,s uch as maleica nhydride [145] or citraconic acid, [151] which can undergo cross-linking ath igh temperature.…”

“…[149,150] M n values of up to 30 000 gmol À1 were obtained from the bulk polymerization at 80 8Cf or over 48 h. Compared with scandium, bismuth is particularlyi nteresting because it combinest wo advantages:lower toxicity and ah igher efficiency as an esterification catalyst. [150] Moreover,these metal-based Lewis acid catalysts are particularly interesting for monomers containing vinyl groups,s uch as maleica nhydride [145] or citraconic acid, [151] which can undergo cross-linking ath igh temperature. Rare-earth catalysts, which are highly reactive under mild conditions, relative to classical organometallic compounds, are thus adapted catalysts for reactions involving these unsaturated monomers.…”