title: Which polyesters can mimic polyethylene?
abstract: Self-metathesis of erucic acid by [(PCy(3))(η-C-C(3)H(4)N(2)Mes(2))Cl(2)Ru = CHPh] (Grubbs second- generation catalyst) followed by catalytic hydrogenation and purification via the ester yields 1,26-hexacosanedioate (>99% purity). Polyesterification with 1,26-hexacosanediol, generated from the diester, affords polyester-26,26, which features a T(m) of 114 °C (T(c) = 92 °C, ΔH(m) = 160 J g(-1)). Ultralong-chain model polyesters-38,23 (T(m) = 109 °C) and -44,23 (T(m) = 111 °C), generated via multistep procedures including acyclic diene metathesis polymerization, underline that melting points of such aliphatic polyesters do not gradually increase with methylene sequence chain length. Available data suggest that to mimic linear polyethylenes thermal properties, even longer sequences, amounting to at least four times a fatty acid chain, fully incorporated in a linear fashion are required.
authors.affiliation: Department of Chemistry, University of Konstanz, 78464 Konstanz, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Stempfle
authors.forename: Patrick
authors.initials: P
authors.lastname: Ortmann
authors.forename: Stefan
authors.initials: S
authors.lastname: Mecking
mesh_terms: D004883:Erucic Acids / Q000737:chemistry; D006865:Hydrogenation; D008956:Models, Chemical; D011091:Polyesters / Q000138:chemical synthesis / Q000737:chemistry*; D020959:Polyethylene / Q000138:chemical synthesis / Q000737:chemistry*; D058105:Polymerization; D044366:Transition Temperature
chemical_list: D004883:Erucic Acids; D011091:Polyesters; C049811:erucic acid; D020959:Polyethylene