Thiol-functionalized copolymeric polyesters by lipase-catalyzed esterification and transesterification of 1,12-dodecanedioic acid and its diethyl ester, respectively, with 1-thioglycerol

Abstract

Copolymeric polyoxoesters containing branched-chain methylenethiol functions, i.e.poly(1,12-dodecanedioic acid-co-1-thioglycerol) and poly(diethyl 1,12-dodecanedioate-co-1-thioglycerol), were formed by lipase-catalyzed polyesterification and polytransesterification of 1,12-dodecanedioic acid and diethyl 1,12-dodecanedioate, respectively, with 1-thioglycerol (3-mercaptopropane-1,2-diol) using immobilized lipase B from Candida antarctica (Novozym 435) in vacuo without drying agent in the reaction mixture. After 360 to 480 h, both polyoxoesters were purified by extraction from the reaction mixtures followed by solvent fractionation. The precipitate of poly(1,12-dodecanedioic acid-co-1-thioglycerol) demonstrated a M W of 170,000Da, whereas a M W of 7,100 Da only was found for poly(diethyl 1,12-dodecanedioate-co-1-thioglycerol). Both polycondensates were analyzed by GPC/SEC, alkali-catalyzed transmethylation, NMR-and FTIR-spectrometry.

Lipases as Efficient Catalysts in the Synthesis of Monomers and Polymers with Biomedical Applications

“…Under similar conditions a copolymeric polyoxoesters containing branched-chain methylenethiol functions, i.e., poly(1,12dodecanedioic acid-co-1-thioglycerol) and poly(diethyl 1,12dodecanedioate-co-1-thioglycerol) was also obtained by Novozym 435-catalyzed polyesterification and polytransesterification of 1,12dodecanedioic acid and diethyl 1,12-dodecanedioate, respectively, with 1-thioglycerol (3-mercaptopropane-1,2-diol) [211].…”

Biocatalysis for Biobased Chemicals

“…Polycondensations with structurally different monomers have been realized, for example siloxane-containing diacids with diols (Mw = 20,000) [156], diacids with glycerol (Mw = 2,000–6,000) [157,158], thio-glycerol with diacids (Mw = 170,000) [159], diacids with a variety of sugars, sorbitol, erythritol, xylitol, ribitol, mannitol, glucitol, galactitol yielded polyesters with Mw = 10 kDa for galactitol and 75 kDa for Mannitol. The regioselecitivy of the sugar esterifications was mostly consistent in all the sugars to be on the primary hydroxyl groups [160].…”

Trifunctional Trimethyl Citrate Modified Poly(ethylene terephthalate) with Enhanced Tensile Strength and Elongation

“…There are two types of polyester preparation strategies in the industry, which are the direct esterification–polycondensation and the transesterification–polycondensation routine . Since the reactivity of dimethyl monomers (corresponding to transesterification) is higher than that of diacid monomers (corresponding to direct esterification), the temperature and pressure of the transesterification are usually lower than the direct esterification method .…”

“…There are two types of polyester preparation strategies in the industry, which are the direct esterification−polycondensation and the transesterification−polycondensation routine. 19 Since the reactivity of dimethyl monomers (corresponding to transesterification) is higher than that of diacid monomers (corresponding to direct esterification), the temperature and pressure of the transesterification are usually lower than the direct esterification method. 20 For example, during the transesterification/direct esterification stage to fabricate PET, the transesterification routine requires merely ∼220 °C and atmospheric pressure while up to ∼250 °C/300 kPa is needed during the direct esterification routine.…”