Simple One-Pot Synthesis of Fully Biobased Unsaturated Polyester Resins Based on Itaconic Acid

Abstract

For the preparation of fully biobased unsaturated polyester resins (UPRs), the replacement of styrene with alternate nonpetroleum-based monomers turned out to be one of the most challenging tasks. Its complexity lies in the fact that reactive diluents (RD) have to have low viscosity and volatility, good compatibility with prepolymer, and capability to homopolymerize and copolymerize with its unsaturations. In this context, we directed our efforts to develop fully biobased UPRs using the dialkyl itaconates as an alternative to styrene. Therefore, a series of 100% biobased UPRs were prepared from itaconic acid and 1,2-propandiol and diluted by dialkyl itaconates. The resins were characterized by Fourier transform infrared spectroscopy, NMR, volatility, and viscosity measurements, while the cured samples were characterized by dynamic mechanical properties, thermomechanical analysis, thermogravimetric analysis data, and tensile tests. The influence of RD structure on the properties of cured samples was discussed in detail. It was shown that the prepared resins had evaporation rates of dialkyl itaconates of several orders of magnitude less compared to styrene. The cured resins with dimethyl itaconate showed comparable or even better thermal and mechanical properties compared to the one with styrene. This investigation showed that itaconic acid and dialkyl itaconates are promising bioresources for the preparation of fully biobased UPRs for mass consumption.

Insights into post‐polymerisation modification of bio‐based unsaturated itaconate and fumarate polyesters via aza‐michael addition: Understanding the effects of CC isomerisation

“…Several studies report regioisomerisation of itaconate during polyester synthesis, ranging from <10% (relative to itaconate) as described by Spasojevic (7%), Farmer (8%), (a) and Teramoto (9%), increasing up to nearly 60% in the Takasu's protocol using itaconic anhydride and 1,2‐epoxybutane with a magnesium ethoxide initiator . Regioisomerisation has additionally been observed to occur during addition of dicarbonyl pendants to free unsaturated sites; with an increasing ratio of mesaconate seen for high (>75%) but not complete addition .…”

Inherently degradable cross-linked polyesters and polycarbonates: resins to be cheerful

“…There is thus potential for M10 and its derivatives to be used as bio-based resources for unsaturated polyester resins. 112…”

Post‐polymerization modification of bio‐based polymers: maximizing the high functionality of polymers derived from biomass

“…Spasojevic and colleagues very recently demonstrated a one‐pot route to fully bio‐based thermosets where poly(1,2‐propylene itaconate) UPE is first formed as a pre‐polymer ( M n 1.3 kg mol −1 ) and subsequently cured via the use of a range of dialkyl itaconate reactive diluents (RDs) (Scheme ) . This is an interesting example of how traditional RDs such as acrylate and styrene can be replaced by bio‐based alternatives, and an additional benefit of itaconates is that the presence of two ester groups allows for fine tuning of the reactivity of the RD and the final properties of the thermoset produced by careful selection of the alkyl groups.…”