Enzymatic One-Pot Route to Telechelic Polypentadecalactone Epoxide: Synthesis, UV Curing, and Characterization

Abstract

In an enzymatic one-pot procedure immobilized lipase B from Candida antarctica was used to synthesize semicrystalline diepoxy functional macromonomers based on glycidol, pentadecalactone, and adipic acid. By changing the stoichiometry of the building blocks, macromonomers of controlled molecular weight from 1400 to 2700 g mol(-1) could be afforded. The enzyme-catalyzed reaction went to completion (conversion >or=95%) within 24 h at 60 degrees C. After removal of the enzyme, the produced macromonomers were used for photopolymerization without any purification. The macromonomers readily copolymerized cationically with a cycloaliphatic diepoxide (Cyracure UVR-6110; CA-dE) to high conversion. The cross-linked copolymers formed a durable film with a degree of crystallinity depending on the macromonomer size and amount of CA-dE used, without CA-dE the macromonomers homopolymerized only to a low degree. Combined with CA-dE conversions of 85-90% were determined by FT-Raman spectroscopy. The films became more durable once reinforced with CA-dE, increasing the cross-link density and reducing the crystallinity of the PDL segments in the films.

Hydrolases Part I: Enzyme Mechanism, Selectivity and Control in the Synthesis of Well-Defined Polymers

“…This has important consequences in preparation of α, ω-functionalized polyesters, which are currently being explored in a variety of applications [111,112]. A systematic study by Heise and coworkers on the initiating efficiency of different initiators (1-3 in Fig.…”

“…perform reactions under equilibrium conditions), allows high endgroup fidelity in a lipase-catalyzed ROP, even in a one-pot procedure [58,80,111,112,[116][117][118]. Initiation with mercapto-ethanol or 6-mercapto-1-hexanol in lipasecatalyzed ROP of CL and ω-pentadecanolactone (PDL), respectively, resulted in high initiator incorporation (95%).…”

Green process for green materials: viable low-temperature lipase-catalysed synthesis of renewable telechelics in supercritical CO 2

“…Recently, great importance has been given to low molecular weight (between 1000 and 4000 g/mol) telechelic polyesters (8)(9)(10)(11). These are functional polymers that carry the same functional group at both ends (12) and find applications in surface modification (8,9), medical materials (13), block copolymer formation (14), cross-linked networks (10,15) etc. Low molecular weights are often desirable in order to obtain low-viscosity materials and good filmability (8,10,11).…”

“…These are functional polymers that carry the same functional group at both ends (12) and find applications in surface modification (8,9), medical materials (13), block copolymer formation (14), cross-linked networks (10,15) etc. Low molecular weights are often desirable in order to obtain low-viscosity materials and good filmability (8,10,11). Furthermore, if a cross-linkable system is the desired product, low molecular weight between the reactive moieties is necessary in order to achieve a high cross-link density and therefore a tougher network (8,10,15).…”

“…Low molecular weights are often desirable in order to obtain low-viscosity materials and good filmability (8,10,11). Furthermore, if a cross-linkable system is the desired product, low molecular weight between the reactive moieties is necessary in order to achieve a high cross-link density and therefore a tougher network (8,10,15). To achieve a fully green process, enzymes have been exploited as substitutes for metal-based catalysts that are potentially toxic (16)(17)(18)(19), expensive, and require high temperatures (normally greater than 160°C for polycondensations) to work effectively (20)(21)(22)(23)(24).…”