Effect of Eggshell Powder Using for an Extender on the Mechanical and Thermal Behaviors of Polylactic Acid Composites

In this paper, the composites between polylactic acid (PLA) and eggshell powder (ESP) from the chicken shell were prepared by melt blending method in the internal mixer and then injection molded to produce the bio-composite specimen. The effect of the ESP concentration in the composites was investigated on the mechanical and thermal behaviors. The results indicated that the tensile strength and elongation decreased with increased ESP loading. Furthermore, the impact strength was not altered for PLA filled system with 10-30% of ESP. At the 10%wt of ESP in the PLA-composites was not significantly different of the onset (Tonset) and maximum degradation temperature (Td) from neat PLA but at higher ESP loading, Tonset and Td tend to decrease, therefore ESP could be able to accelerate degradation in the composites. The cold crystallization (Tcc) showed decreasing when the ESP was incorporate about 10-30 %wt. Otherwise, the incorporation of ESP affected on the declination of crystallinity in the PLA composites. The morphology, size and elements were examined using a scanning electron microscope (SEM) coupled with an energy dispersive X-ray system (EDX). It was indicated that agglomeration of ESP in the PLA matrix.

Microbial glycoconjugates in organic pollutant bioremediation: recent advances and applications

The large-scale application of organic pollutants (OPs) has contaminated the air, soil, and water. Persistent OPs enter the food supply chain and create several hazardous effects on living systems. Thus, there is a need to manage the environmental levels of these toxicants. Microbial glycoconjugates pave the way for the enhanced degradation of these toxic pollutants from the environment. Microbial glycoconjugates increase the bioavailability of these OPs by reducing surface tension and creating a solvent interface. To date, very little emphasis has been given to the scope of glycoconjugates in the biodegradation of OPs. Glycoconjugates create a bridge between microbes and OPs, which helps to accelerate degradation through microbial metabolism. This review provides an in-depth overview of glycoconjugates, their role in biofilm formation, and their applications in the bioremediation of OP-contaminated environments.

Mitigation of vacancy with ammonium salt-trapped ZIF-8 capsules for stable perovskite solar cells through simultaneous compensation and loss inhibition

Due to the easily loss nature of ions during synthesis or service process, the vacancies in perovskite film is ubiquity, which accelerate degradation of perovskite materials and seriously hamper the...

Graphene Oxide Induces Ester Bonds Hydrolysis of Poly-l-lactic Acid Scaffold to Accelerate Degradation

Poly-l-lactic acid (PLLA) possesses good biocompatibility and bioabsorbability as scaffold material, while slow degradation rate limits its application in bone tissue engineering. In this study, graphene oxide (GO) was introduced into the PLLA scaffold prepared by selective laser sintering to accelerate degradation. The reason was that GO with a large number of oxygen-containing functional groups attracted water molecules and transported them into scaffold through the interface microchannels formed between lamellar GO and PLLA matrix. More importantly, hydrogen bonding interaction between the functional groups of GO and the ester bonds of PLLA induced the ester bonds to deflect toward the interfaces, making water molecules attack the ester bonds and thereby breaking the molecular chain of PLLA to accelerate degradation. As a result, some micropores appeared on the surface of the PLLA scaffold, and mass loss was increased from 0.81% to 4.22% after immersing for 4 weeks when 0.9% GO was introduced. Besides, the tensile strength and compressive strength of the scaffolds increased by 24.3% and 137.4%, respectively, due to the reinforced effect of GO. In addition, the scaffold also demonstrated good bioactivity and cytocompatibility.

Chemical amplification accelerates reactive oxygen species triggered polymeric degradation

Chemical amplification strategy is employed to accelerate degradation of ROS-responsive polymeric nanoparticles.

COMPARISON OF MANGANESE LAURATE, MANGANESE PALMITATE AND MANGANESE STEARATE ON ACCELERATING DEGRADATION OF HDPE DURING NATURAL WEATHERING

High density polyethylene (HDPE) degradation has been studied. In this study, HDPE was incorporated with manganese laurate, manganese palmitate and manganese stearate as pro-oxidant additives. Preparation of samples were conducted by adding the HDPE resin with pro-oxidant additives in the range of 0-1.0 wt %. A twin screw extruder was employed prior to the injection molding technique. Samples were subjected to natural weathering for the maximum duration of 24 weeks. Assessments on the change of the properties of samples after natural weathering treatment were conducted by FTIR analysis, tensile testing and average molecular weight analysis. In term of their capabilities to accelerate degradation of HDPE, manganese stearate exhibited more influence than manganese laurate and manganese palmitate. The carbonyl group’s peak arises as a result of oxidation during the treatment as revealed by FTIR traces. Samples with pro-oxidant additives shows a loss of their strain at break. The amount of pro-oxidant additives increases the degradation of samples.