Synthesis and properties of renewable, aliphatic polyesters from thiol-ene and acyclic diene metathesis polymerization of alpha, omega-unsaturated dienes derived from fatty acids

Authors: Moser, Bryan; Banks, Benetria; Doll, Kenneth - Ken

Submitted to: American Oil Chemists' Society Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 2/22/2021
Publication Date: 5/3/2021
Citation: Moser, B.R., Banks, B.N., Doll, K.M. 2021. Synthesis and properties of renewable, aliphatic polyesters from thiol-ene and acyclic diene metathesis polymerization of alpha, omega-unsaturated dienes derived from fatty acids [abstract]. VIRTUAL 2021 American Oil Chemists' Society Annual Meeting and Expo.

Interpretive Summary:

Technical Abstract: Conventional petrochemical plastics are non-renewable, proliferate in the environment as waste, are harmful to animals who ingest their residues, and resist microbial degradation. Renewable alternatives that address these deficiencies are thus an important area of current research. A promising approach is the production of biodegradable, aliphatic polyesters from fats and oils that mimic the properties of industrial polyolefins, such as polyethylene, due to the presence of long-chain aliphatic repeat units arising from the fatty acid backbone. We thus report herein the synthesis and properties of renewable, aliphatic polyesters prepared via acyclic diene metathesis (ADMET) and thiol-ene polymerization of alpha, omega-unsaturated monomers derived from 9-decenoic acid (9DA), a terminal fatty acid readily obtained from ethenolysis of oleic acid. Condensation of 9DA with ethylene glycol, 9-decen-1-ol, and allyl 9-decenoate provided alpha, omega-dienes suitable for subsequent polymerization. ADMET homopolymerizations were performed in the presence of catalytic Hoveyda-Grubbs second generation catalyst with loss of ethylene to yield an unsaturated polyester. Thiol-ene copolymerizations were conducted photochemically with stoichiometric 1,2-ethanedithiol and 1,3-propanedithiol as linkers along with catalytic 2,2-dimethoxy-2-phenylacetophene as a photoinitiator to give saturated poly(thiother-ester)s. Both reactions were performed without solvent and proceeded in high yield to the intended polymeric targets. Properties such as molecular weight, glass transition temperature, thermal stability, and green metrics were then determined. In general, the thiol-ene polymers gave higher molecular weights, polydispersities, atom and carbon economies, as well as higher melting, crystallization, and glass transition temperatures relative to their ADMET counterparts. These results and others will be presented and their relevance to industrial applications will be discussed.