Thermal Stabilization of Recycled PET Through Chain Extension and Blending with PBT

This study investigates the effect of using a multifunctional epoxide chain extender (Joncryl^® ADR 4468) on the thermal stabilization and rheological properties of recycled polyethylene terephthalate (R-PET) and its blends with polybutylene terephthalate (PBT). The R-PET samples were prepared without and with chain extender (CE) contents of 0.4 wt% and 0.8 wt%. R-PET/PBT blends with weight ratios of 75w/25w, 50w/50w and 25w/75w were also prepared without and with a given CE content of 0.2 wt%. The thermal stability of the melt blended samples was analyzed through small amplitude oscillatory shear (SAOS) rheological experiments. The structure of the samples was evaluated using a Fourier transform infrared (FTIR) spectrometer. While the dynamic rheological properties of R-PET were improved with the addition of Joncryl and by blending with PBT, during the SAOS rheological experiments, the complex viscosity of R-PET further increased due to the concurrent polycondensation of R-PET and the resumption of Joncryl reaction with R-PET molecules. These reactions during the rheological experiments were further expedited with increasing the testing temperature. On the other hand, in R-PET/PBT blends, the reactivity of Joncryl was more noticeable in blends with higher R-PET contents due to the higher available internal reactive sites of much shorter R-PET molecules. It was observed that the addition of only 0.2 wt% Joncryl to the blends of R-PET/PBT (75w/25w) dramatically improves the thermal stability and dynamic rheological properties of R-PET and most likely its processability.

     

Satellite-based monitoring of meteorological drought over different regions of Iran: application of the CHIRPS precipitation product

Environmental Science and Pollution Research - In the present study, the spatiotemporal evaluation of the Climate Hazards Group InfraRed Precipitation with Station (CHIRPS) satellite precipitation...     

Production of biodegradable pots from cattle manure and wood waste: effects of natural binders on mechanical performances and biodegradability

Environmental Science and Pollution Research - The present study seeks to investigate the use of husbandry waste and sawdust in the construction of degradable pots as a suitable alternative to...     

The role of environmental transformational leadership in employees’ influencing organizational citizenship behavior for environment well-being: a survey data analysis

Environmental Science and Pollution Research - Many researchers and intellectuals focused on the topic of organizational citizenship behavior for the environment (OCBE); however, employees’...     

A game-theoretic approach to designing an optimal code of conduct program to promote supplier sustainability in a supply chain

Environmental Science and Pollution Research - In recent years, suppliers in developing countries face the challenge of their low technological and knowledge-related capabilities to enhance...     

Biochemical profiling of lead-intoxicated impaired lipid metabolism and its amelioration using plant-based bioactive compound

The aim of this study was to investigate the lead (Pb)-induced lipid metabolism impairment and its amelioration using plant-based therapeutic interventions. Pb-induced hepatotoxicity can disturb the normal levels of natural antioxidant enzymes including glutathione (GSH) and superoxide dismutase (SOD) exerting a crucial impact on membrane unsaturated fatty acids (FA), hence leading to lipid peroxidation. Furthermore, Pb toxicity can also alter the regulation of various hormones involved in the synthesis of 3-hydroxy-methyl glutaryl CoA (HMG-CoA reductase), leading to an impairment in normal levels of serum cholesterol and other associated conjugated lipid molecules such HDL-cholesterol, LDL-cholesterol and VLDL-cholesterol. In this study, the lipoprotein fractions, cholesterol, triglyceride (TGs) and biomarkers of liver functions were estimated by employing respective assay kits. The levels of antioxidant enzymes, FFAs and HMG-CoA reductase were determined by employing sandwich ELISA method. The administration of PbAc in experimental rats induced a significant disturbance in lipid profile (P < 0.05) accompanying a significant reduction in natural antioxidant defence system (P < 0.05). The significant alteration in the levels of serum antioxidant enzymes can lead to membrane lipid peroxidation that is reflected by a significantly (P < 0.05) high level of serum MDA in PbAc-induced experimental rats. However, the administration of resveratrol proved therapeutically effective in the treatment of Pb toxicity. Overall, the results of this study accompanying histopathological examination had proved the ameliorating effect of resveratrol in Pb-induced lipid metabolism impairment by adopting vitamin C as a standard therapeutic intervention.

     

Conceptualizing sustainable–responsible tourism indicators: an interpretive structural modeling approach

Environment, Development and Sustainability - Despite decades of debate and theoretical and practical activity related to the sustainability of tourism, its implementation remains difficult. The...     

Economic and financial impact of the COVID-19 pandemic in South Asia

Environmental Science and Pollution Research - The world is facing a COVID-19 pandemic outbreak with an unprecedented and enormous impact on the lives of humankind. The economic engine has suffered...     

Global warming and export competitiveness of agriculture sector: evidence from heterogeneous econometric analysis of Pakistan

Environmental Science and Pollution Research - The increase in average annual temperature due to greenhouse gases emission is posing threat to the agriculture sector across the globe. Pakistan is...     

Assessing the impact of mechanism of green public consumption policy on environmental equity: evidence from China

Environment, Development and Sustainability - This study investigates the impact of the mechanism of green public consumption policy on environmental equity and provides a feasible reference for...