Epoxidation of Bacterial Polyesters with Unsaturated Side Chains. I. Production and Epoxidation of Polyesters from 10-Undecenoic Acid

Abstract

Poly(3-hydroxyoctanoate-co-3-hydroxy-10-undecenoate)s (PHOUs) with controlled amounts of unsaturated side chains were produced by Pseudomonas oleovorans from various mixtures of 10-undecenoic acid and octanoic acid. Epoxidation of the unsaturated side chains in PHOU, by reacting the polymer with m-chloroperbenzoic acid (MCPBA) in homogeneous solution, was readily carried out. After complete epoxidation, changes in the molecular weights and thermal transitions of the PHOUs were investigated by gel permeation chromatography (GPC) and differential scanning calorimetry (DSC), respectively, and the thermal stabilities of the initial and epoxidized polymers were measured by thermogravimetric analysis (TGA). The acidic conditions used for the epoxidation reaction did not result in a significant decrease in molecular weight of the PHOUs. The epoxidized PHOUs were completely soluble, indicating that cross-linking did not occur, but transformation of the vinyl groups in PHOU into epoxide groups caused a decrease in the melting temperature and the enthalpy of melting. In contrast, the glass transition temperatures increased in a linear manner with epoxide group content in the product polymer, and the thermal degradation behavior of the epoxidized polymer was considerably different from that of the initial polymer.

Advanced functionalization of polyhydroxyalkanoate via the UV-initiated thiol-ene click reaction

“…To date, a number of reports on the use of Pseudomonas for the preparation of PHA incorporating unsaturated monomers have been published (Ashby and Foglia 1998; Constantin et al 1999;Gagnon et al 1994a, b;Huijberts et al 1992;Lageveen et al 198inhi8;Lee et al 2001;Park, Lenz and Goodwin 1998;Sun et al 2009). In these studies, various monomers bearing unsaturated units were supplied through β-oxidation and de novo fatty acid synthetic pathways.…”

“…In these studies, various monomers bearing unsaturated units were supplied through β-oxidation and de novo fatty acid synthetic pathways. In this study, undecylenate, which contains a vinyl group, was used as the source of unsaturated monomer to produce 3HAs bearing a vinyl group at the alkyl side chain terminal (Constantin et al 1999;Gagnon et al 1994a, b;Park, Lenz and Goodwin 1998).…”

“…Campos et al reported the synthesis of various macromolecules via the UV-initiated thiol-ene click reaction, which proceeded quantitatively, with a high degree of specificity in a matter of minutes (Campos et al 2008;Killops et al 2008). However, the majority of PHAs studied to date contain no functional groups, and few groups have reported such modification of PHAs (Constantin et al 1999;Gagnon et al 1994a, b;Park, Lenz and Goodwin 1998). Thus, to establish a synthetic methodology for novel PHAs, we explore the preparation of PHA bearing vinyl groups (by undecylenate feeding) and their subsequent chemical modifications using a click reaction.…”

Synthetic routes to degradable copolymers deriving from the biosynthesized polyhydroxyalkanoates: A mini review

“…Poly(3-hydroxy undecenoate) (PHU, Figure 2), being obtained from P. oleovorans with a mixture of sodium octanoate and 10-undecenoic acid [38], is a novel and multifunctional type of PHA, which has attracted much attention owing to its unsaturated side chains. These vinyl groups can be oxidized to carboxylic acid using osmium tetraoxide/oxone or acidic potassium permanganate treatment [39,40], or converted to alcohol (nearly 100% hydroxylation) using 9-borobicyclononane [41].…”

Making Green Polymers Even Greener:Towards Sustainable Production of Polyhydroxyalkanoates from Agroindustrial By-Products

“…However, the most commonly applied route for tailoring PHAs is their in situ functionalization by biosynthetically producing side chains with terminal double bonds followed by chemistry (revised in Scholz, 2010). PHAs with terminal double bonds were first described by Lageveen et al (1988) and received a lot of follow-up research (Fritzsche et al, 1990;Hartmann et al, 2006;Park et al, 1998). In Pseudomonads, PHAs that are formed from glycerol, gluconate, or related sugars have a different composition with respect to PHAs obtained from fatty acids.…”