Polymer Thermosets from Multifunctional Polyester Resins Based on Renewable Monomers

Abstract

The use of monomers based on natural materials as a future supply of raw materials has gained more interest in the last decade. Sources ranging from wood to plant oils and algae are exploited as alternatives to traditional fossil‐based resources for the synthesis of polymeric materials. The use of these raw materials is not only of interest because of its abundance, but also in terms of price, durability, and/or biodegradability. In the present study, a series of resins utilizing a monomer derived from birch bark is prepared. The thermoset resins are formed by reacting an epoxy‐functional ω‐hydroxy fatty acid with methacrylate monomers using enzyme catalysis to form multifunctional resins via a one‐pot synthesis. The derived oligomers are crosslinked through different polymerization routes to produce thermosets with different properties and/or functionalities. This approach allows natural‐based resins with tuned functionalities and mechanical and thermal properties to be obtained.

Fully bio-based aliphatic thermoset polyesters via self-catalyzed self-condensation of multifunctional epoxy monomers directly extracted from natural sources

“…The retrieval of EFA was divided into two steps where the first step was a removal of extractives performed according to a method described in the literature. 30 The residue of the outer birch bark powder was left to dry: first in air for 24 h and then in a vacuum oven at 50°C for 24 h. The second step was conducted by a modified hydrolysis process previously described in the literature 31,32 where the dry ground outer birch bark was weighed into a round-bottom flask and impregnated by reduced pressure with 0.8 M NaOH solution in the ratio of 1 g bark per 10 mL solution. The round-bottom flask was then immersed into a 100°C oil bath and refluxed under continuous stirring.…”

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).…”

Step‐Growth Polymerization in the 21st Century

“…Johansson et al used the same enzyme to obtain renewable epoxide-containing polyester prepolymers, which were subsequently crosslinked by different chemistries, allowing a tailoring of the mechanical and thermal properties, as well as a possible post-functionalization of the formed fi lms. [ 5 ] Schlaad et al also obtained unsaturated polycondensates from a renewable resource, amino acids in this case, but using acyclic diene metathesis (ADMET) polymerization. [ 6 ] Although doublebond isomerization could not be avoided in this olefi n metathesis process, the polymers were suitable for post-polymerization modifi cation via thiol-ene chemistry.…”