Polyhydroxyalkanoate-based natural–synthetic hybrid copolymer films: A small-angle neutron scattering study

Polyhydroxyalkanoates have attracted attention as biodegradable alternatives to conventional thermoplastics and as biomaterials. Through modification of their biosynthesis using Pseudomonas oleovorans, we have manipulated the material properties of these biopolyesters and produced a natural–synthetic hybrid copolymer of polyhydroxyoctanoate-block-diethylene glycol (PHO-b-DEG). A mixture of PHO and PHO–DEG were solvent cast from analytical grade chloroform and analysed using small-angle neutron scattering. A scattering pattern, easily distinguished above the background, was displayed by the films with a diffraction ring at q 0.12 Å . This narrow ring of intensity is suggestive of a highly ordered system. Analysis of the diffraction pattern supported this concept and showed a d-spacing of approximately 50 Å. In addition, conformation of the hybrid polymer chains can be manipulated to support their self-assembly into ordered microporous films. r 2006 Elsevier B.V. All rights reserved. PACS: 61.12.Ex; 61.41.+e; 81.05.Lg; 87.15.Rn