Polyhydroxyalkanoates mechanical properties

Huisman GW, Wonink E, Meima R, Kazemier B, Terpstra P, Witholt B (1991) Metabolism of poly(3-hydroxyalkanoates) (PHAs) by Pseudomonas oleovorans. J Biol Chem 266 2191-2198 II Yun S, Gadd GE, LateUa BA, Lo V, Russell RA, Holden PJ (2008) Mechanical properties of biodegradable polyhydroxyalkanoates/single wall carbon nanotube nanocomposite films. Polym Bull 61 267-275... 

Polyhydroxyalkanoates, Polyhydroxybutyrate, History, Bacterial synthesis. Chemical synthesis. Genetic engineering. Mechanical properties. Thermal transitions. Crystallization, Plasticizers, Thermal degradation. Processing, Applications... 

The family of polyhydroxyalkanoates (PHA) exhibits a wide variety of mechanical properties from hard crystalline to elastic, depending on the composition of monomer units [12]. Solid-state poly(3-hydroxybutyrate) (P(3HB)) is a compact right-handed helix with a two-fold screw axis (i.e. two monomer units complete one turn of the helix) and a fibre repeat of 0.596 nm [13]. The stereoregularity of P(3HB) makes it a highty crystalline material. Its melting point is around 177°C close to that of polypropylene, with which it has other similar properties, although the biopolymer is stiffer and more brittle. 

Stobinski L, Lesiak B, Kover L, Toth J, Biniak S, Trykowski G, Judek J (2010) Multiwall carbon nanotubes purification and oxidation by nitric acid studied by the FTIR and electron spectroscopy methods. J Alloy Compd 501 77-84 Sudesh K, Abe H, Doi Y (2000) Synthesis, structure and properties of polyhydroxyalkanoates biological polyesters. Prog Polym Sci 25 1503-1555 Tang W, Santare MH, Advani SG (2003) Melt processing and mechanical property characterization of multi-walled carbon nanotube/high density polyethylene (MWNT/HDPE) composite films. Carbon 41 2779-2785... 

Moving from the Cj and C2 sidechain polyhydroxyalkanoates to longer sidechains leads to a progressive change in the crystallinity and mechanical properties of the resulting copolymers. 

Zhao K, Deng Y, Chen J Ch et al (2003) Polyhydroxyalkanoate (PHA) sctiffolds with good mechanical properties and biocompatibility. Biomaterials 24 KM 1-1045... 

Polyhydroxyalkanoate (PHA) scaffolds with good mechanical properties and biocompatibility. Biochem. Eng. 

Zhao K, Deng Y, Chen CJ and Chen GQ, Polyhydroxyalkanoate (PHA) Scaffolds with Good Mechanical Properties and BiocompatibiUty. Biomaterials, 2003, 24 (6) 1041-1054. 

Recently, there has been considerable effort in the polymer industry towards developing more environmentally fiiendly materials. Bio-derived polymers have emerged as a potential alternative to conventional fossil fuel-based materials. They have similar mechanical properties to typical polymers, but are derived fi om renewable resomces and ean decade under certain conditions [1]. Two polymers that are classified as bioderived polymers are the general class of polymers known as polyhydroxyalkanoates (PHA), and poly(lactic acid) (PLA). 

However, extensive research on the scarcely explored field of nanocomposite formulation based on polyhydroxyalkanoates is needed in order to enhance their mechanical, and other, properties, which can be manipulated to suit end-users requirements in order to meet a wide range of applications. 

---