Renewable Aliphatic Polyesters from Fatty Dienes by Acyclic Diene Metathesis Polycondensation

Abstract

Three renewable, linear, aliphatic polyesters were prepared by Acyclic diene metathesis (ADMET) polymerization of α,ω-dienes derived from fatty acids. Condensation of 9-decenoic acid with allyl 9-decenoate, ethylene glycol, and 9-decen-1-ol proceeded in high conversion (≥94%) and purity (>99%) to give α,ω-dienes suitable for subsequent polycondensation. Polymerization was achieved using 1.0 mol% Hoveyda-Grubbs second-generation metathesis catalyst in combination with 2.0 mol% 2,6-dichloro-1,4-benzoquinone as an isomerization inhibitor under vacuum to drive equilibria toward polymer formation via ethene removal. Polymerization in the presence of solvent promoted ring-closing metathesis (RCM) at the expense of polymer, with cyclization increasing as the concentration of monomer decreased. Thus, ADMET polymerizations were performed in bulk to mitigate RCM. The resulting polymers with M n and Ð that ranged from 6.6 to 8.9 kDa and 1.75-2.14, respectively, contained 76% or more of renewable carbon content and exhibited atom and carbon economies of greater than 84%. Melt (T m ) and crystallization (T c ) temperatures were 20.8-48.4 C and 3.8-37.6 C, respectively, and increased as ester density decreased within polymer structures. Sub-ambient glass transitions ranged from −10.

Synthesis of Biobased Long-Chain Polyesters by Acyclic Diene Metathesis Polymerization and Tandem Hydrogenation and Depolymerization with Ethylene

“…a The results thus clearly indicate the formation of polymers by ADMET polymerization. 22 − 34 , 43 − 59 The resultant polymers (PE1) possess a sole (rather sharp) melting temperature ( T m ) at 46.9 °C (run 3, M n = 15,900), whereas the T m value was affected by the molecular weight [Figure S39, Supporting Information , T m value = 46.9 °C ( M n = 15,900, run 3), 40.9 °C (12,400, run 6), 36.6 °C (8500, run 2), and 34.8 °C (7700, run 1)].…”

Synthesis of Bio-Based Aliphatic Polyesters from Plant Oils by Efficient Molecular Catalysis: A Selected Survey from Recent Reports

“…However, as shown in Figure a, the degree of the odd–even effect decreases with increasing number of methylene units as well as methylene units in the diol units ( X = 10 vs 20); the T m values thus are dependent on the total number of methylene groups and their distribution within the polymer chain . It was demonstrated that the T m values higher than 100 °C were achieved by increasing the percentage of long, , crystallizable methylene segments; the T m value should finally converge toward linear polyethylene by further increasing chain lengths of the aliphatic repeat units. ,, …”

“…Synthesis of high-molecular-weight ( M n > 150,000) poly­(pentadecalactone) was achieved recently by using Al catalyst containing salen ligands. , More recently, numerous examples for catalyzed ROP of various lactones including large-membered rings have been reported; − the progress will provide the possibility in the future. As described below, synthesis of the polymers by acyclic diene metathesis (ADMET) polymerization − and subsequent hydrogenation can also be considered as the alternative route. ,,,,− ,,, …”

“…In particular, as focused on in this Perspective, development of advanced polyesters, which display tunable mechanical properties and biodegradability, from so-called bio-based monomers by precise polymerization techniques attracts considerable attention. − Plant oils, ,− ,− generally obtained as fatty acids or fatty acid methyl esters by chemical modifications, have been considered as a useful renewable feedstock especially for synthesis of the (semicrystalline) aliphatic polyesters, whereas many studies have thus been known for synthesis of polyesters from the other renewable resources such as lignin, sugars, ,,− and terpenes. ,, As described below, study on efficient conversion of plant oils, such as isomerization alkoxycarbonylation, olefin metathesis (including so-called ethenolysis) routes, or new catalysts for the transesterification, attracts considerable attention.…”

Production of Industrially Useful and Renewable p‐Cymene by Catalytic Dehydration and Isomerization of Perillyl Alcohol

“…As part of our continuing efforts to produce aliphatic polyesters from renewable starting materials (Moser et al, 2019, 2020), we were originally attempting to esterify 9‐decenoic acid with 4 in the presence of catalytic p TsOH in refluxing toluene to give the corresponding tris ‐unsaturated perillyl decenoate as a monomer for subsequent acyclic diene metathesis polymerization and thiol‐ene photochemical polycondensation. The esterification procedure had proven simple and effective for several previous condensations involving different alcohol/acid combinations (Moser, 2014; Moser et al, 2019, 2020), but in this case the expected ester was not observed. Instead, a mixture comprised of 4 , unreacted 9‐decenoic acid, and a curiously high amount of 1 (31%) was noted.…”