XPS, AFM and DSC surface and morphology studies of CA/PHAmcl polymeric blends

Full text: Cellulose acetate (CA) is one of the (biodegradable) polymers produced from naturally available plant substrate cellulose; it comes from the reaction of cellulose with acid acetic. Medium-chain-length polyhydroxy alkanoates (PHAmcl), biodegradable and also biocompatible, are from the family of polyesters and are produced from natural resources by Pseudomonas putida. The properties of polymeric blends depend upon the miscibility of their homopolymers constituents at the molecular scale. Although there are a large number of blends already available, the development of improved and new blends are required for a number of applications. Thus, in an attempt to improve mechanics and transport properties of the dense and porous cellulose acetate lms, polymeric blends with different concentrations of medium-chain-length polyhydroxy alkanoates (10, 20 and 30%) were obtained and studied. The blends were prepared from the mixture of polymeric solutions with continuos agitation during 6 hours. The Ca/PHAmcl dense lms was then attained by solution casting from di-methyl ketone solution in a controlled atmosphere. By using Atomic Force Microscopy (Am) in contact mode with an V-shape silicon nitrate cantilever, and X-ray Photoelectron Spectroscopy (XP S) with X-ray Mg Kα (1253.60 eV), the blends were characterized and these data were correlated with Differential Scanning Calorimetry (DSc) results in order to study the miscibility and impact on the morphology of the blends, among other properties of interest. (author)