crystallinity

The changes in the crystal structure of polyhydroxybutyrate, polylactide, and their blends during biodegradation under the influence of bacteria and fungi were studied using X-ray diffraction analysis. It was found that microorganisms induce structural transformations in polymers, which occur without significant mass loss of the samples. X-ray diffraction analysis revealed that biodegradation is a complex multifactorial process that depends on the nature of the polymer and microorganisms and is characterized by microstructural changes in the film samples. 

Polydiphenylamine (PDPA) doped with acrylic acid was synthesized by oxidative chemical polymerization. This is a new chemical polymerization method developed for the direct synthesis of emeraldine salt form of polydiphenylamine which exhibits remarkably improved solubility in a common organic solvent. These polymers have been characterized by the physical techniques such as UV-visible, FTIR, XRD and conductivity measurement. The results are discussed with reference to the H2SO4 doped polydiphenylamine.

We focused on hydrolytic degradation kinetics at 310 and 343 K in phosphate buffer to compare PLA and PHB kinetic profiles. Besides, we revealed the kinetic behavior for copolymer PHBV (20 % of 3-hydroxyvalerate) and the blend PHB-PLA (1:1). The intensity of biopolymer hydrolysis is characterized by total weight lost and the viscosity-averaged molecular weight (MW) decrement. The degradation is enhanced in the series PHBV < PHB < PHB-PLA blend < PLA.