Lipase-Catalyzed Epoxy–Acid Addition and Transesterification: from Model Molecule Studies to Network Build-Up

Abstract

Commercially available lipase from Pseudomonas stutzeri (Lipase TL) is investigated as biocatalyst for the formation of an acid-epoxy chemical network. Molecular model reactions are performed by reacting 2-phenyl glycidyl ether and hexanoic acid in bulk, varying two parameters: temperature and water content. Characterizations of the formed products by 1 H NMR spectroscopy and GC-MS combined with enzymatic assays confirm that lipase TL is able to simultaneously promote acid-epoxy addition and transesterification reactions below 100°C and solely the acid-epoxy addition after denaturation at T > 100°C. A prototype biobased chemical network with β-hydroxyester links was obtained using resorcinol diglycidyl ether and sebacic acid as monomers and the lipase TL as catalyst. DSC, ATR-IR, and swelling analysis confirm gelation of the network.

Enriching an Exchangeable Network with One of Its Components: The Key to High-Tg Epoxy Vitrimers with Accelerated Relaxation

“…In the first one, the reaction between epoxides and carboxylic acids was used to prepare networks containing an equimolar amount of ester and alcohol functionalities that were taking part in transesterification reactions. These easy-to-access model vitrimers have been extensively studied by several groups, − but actually, they are neither real elastomers nor real thermosets since their glass transition temperature, T g , is close to the ambient temperature. In order to obtain high- T g vitrimers, which are required in many structural applications, synthesis from anhydrides rather than acids has been proposed as a way of densifying the network.…”

Shape memory elastomers: A review of synthesis, design, advanced manufacturing, and emerging applications

“…The reaction mechanism of transesterification is that an R′ group of an ester is exchanged with an R″ group of alcohol to form a new ester and alcohol by using Lewis acids or strong base catalysts. This dynamic covalent reaction can also be occurred by other methods such as using an enzymatic catalyst and supercritical fluid techniques 136–138 . In industrial scale, this reaction is typically utilized in polyester production, methanolysis and biodiesel production, and fat processing.…”

“…This dynamic covalent reaction can also be occurred by other methods such as using an enzymatic catalyst and supercritical fluid techniques. [136][137][138] In industrial scale, this reaction is typically utilized in polyester production, methanolysis and biodiesel production, and fat processing. Furthermore, this reaction has many advantages such as well-controlling, high conversion and rate, and being environmentally friendly.…”

Epoxy Vitrimer Materials by Lipase-Catalyzed Network Formation and Exchange Reactions

“…Combining NMR analysis and enzymatic assays demonstrated that lipase side groups promote the chain-growth process (epoxy-acid addition) while the enzyme active site is involved in the process of gelation insofar as branching required transesterification to take place (Figure ). It was also demonstrated that lipase TL remains active toward transesterification, even after polymerization at 100 °C …”