The composite materials of biodegradable polymer, poly(lactic acid) (PLA) and fatty acid modified eggshell 15 phr were prepared using a twin screw extruder. Eggshell was modified with different types of fatty acids i.e. propionic acid and oleic acid. Samples were shaped by an injection molding machine to prepare the specimens for mechanical testing. A scanning electron microscope was used to characterize the fracture surface of the composites to ascertain their morphological properties. A universal testing machine and an impact tester were used to investigate the mechanical properties. From the investigation, it was found that the dispersion of eggshell modified with fatty acid in PLA matrix is more uniform than unmodified eggshell. Young’s modulus and tensile strength of the composites between PLA and eggshell modified with propionic acid are higher than neat PLA and PLA/eggshell modified with oleic acid. On the other hands, the relative amount of elongation at break and impact strength of PLA/eggshell modified with propionic acid composite are lower than the composites of PLA and eggshell modified with oleic acid.

In the current study, the effect of modified zeolite using (3-aminopropyl) triethoxysilane in polybutylene succinate (PBS) and polylactic acid (PLA) blend was investigated. Two types of modified zeolite i.e., zeolite 5A and 13X at 3wt% of polymer blend between PBS and PLA were mixed together in twin-screw extruder and thin-films were produced by cast-film extruder. The thickness of each film is between 50 – 70 micron. Mechanical properties, thermal properties, morphological properties and permeability of oxygen, carbon dioxide as well as water vapour were investigated. Adding of zeolite 5A into PBS/PLA blend was found to increase more tensile strength and Young’s moduluswith the comparison to zeolite 13X whereas the zeolite 13X and 5A had increased the percentage of elongation at break more than PBS/PLA blend. The zeolite 5A and 13X tended to increase the thermal stability of the composite films. Gas permeation results showed that PBS/PLA with zeolite 5A allowed the permeation of carbon dioxide and oxygen more than 13X in composite films. Moreover, water vapour transmissionrate of PBS/PLA with zeolite 5A was higher than the one with zeolite 13X.

It is found that rubidium Rb 1+ substitution into the "2212" bismuth superconductors, Bi 2( Sr 1−x Rb x)2 CaCu 2 O 8+y (x = 0.05, 0.1, 0.15, 0.2, and 0.3), produces changes in the copper valency which correlate with changes in the transition temperatures T c . By liquid nitrogen quenching pellets sintered at 800°C, nearly constant oxygen contents are obtained in all pellets fabricated. The c axis length is found to decrease with increasing Rb doping level.