Polyolefins and Polyethylene Terephthalate Package Wastes: Recycling and Use in Composites

Development and characterization of eco-friendly guar gum-agar-beeswax-based active packaging film for cheese preservation

In this work, an attempt has been made to develop a novel natural polysaccharide-based composite packaging biofilm prepared through a solution casting method. The biofilm is prepared from guar gum (GG) and agar-agar (AA) beeswax (BE). The incorporation of 20 % wt./wt.glycerol BE in the blended polymer GG/AA (50:50) (GG/AA/BE20 (50:50)) film shows a reduction in water solubility (66.67 %), water vapour permeability (69.28 %) and oxygen permeability (72.23 %). Moreover, GG/AA/BE20 (50:50) shows an increment in the tensile strength and elongation of a break by 48.32 % and 26.05 %, respectively, compared to pristine GG film. The scanning electron microscopy (SEM) image reveals defects-free smooth surfaces of the film. The Fourier transform-infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) demonstrated the strong hydrogen bonding between GG, AA, and BE. The biodegradable film shows 99 % degradation within 28 days when placed in the soil. The developed film plays a crucial role in extending the shelf life of cheese, effectively maintaining its moisture content, texture, colour, and pH over a span of up to two months from the point of packaging. These results suggest that GG/AA/BE20 (50:50) composite film is a promising packaging film for cheese preservation.

Navigating the nexus: climate dynamics and microplastics pollution in coastal ecosystems

Microplastics (MPs) pollution is an emerging environmental health concern, impacting soil, plants, animals, and humans through their entry into the food chain via bioaccumulation. Human activities such as improper solid waste dumping are significant sources that ultimately transport MPs into the water bodies of the coastal areas. Moreover, there is a complex interplay between the coastal climate dynamics, environmental factors, the burgeoning issue of MPs pollution and the complex web of coastal pollution. We embark on a comprehensive journey, synthesizing the latest research across multiple disciplines to provide a holistic understanding of how these inter-connected factors shape and reshape the coastal ecosystems. The comprehensive review also explores the impact of the current climatic patterns on coastal regions, the intricate pathways through which MPs can infiltrate marine environments, and the cascading effects of coastal pollution on ecosystems and human societies in terms of health and socio-economic impacts in coastal regions. The novelty of this review concludes the changes in climate patterns have crucial effects on coastal regions, proceeding MPs as more prevalent, deteriorating coastal ecosystems, and hastening the transfer of MPs. The continuous rising sea levels, ocean acidification, and strong storms result in habitat loss, decline in biodiversity, and economic repercussion. Feedback mechanisms intensify pollution effects, underlying the urgent demand for environmental conservation contribution. In addition, the complex interaction between human, industry, and biodiversity demanding cutting edge strategies, innovative approaches such as remote sensing with artificial intelligence for monitoring, biobased remediation techniques, global cooperation in governance, policies to lessen the negative socioeconomic and environmental effects of coastal pollution.

Thermomechanical Properties of Virgin and Recycled Polypropylene-High-Density Polyethylene Blends

This paper provides evidence and discusses the variability in the thermomechanical behaviour of virgin and recycled polypropylene/high-density polyethylene blends without the addition of other components, which is sparse in the literature. Understanding the performance variability in recycled polymer blends is of critical importance in order to facilitate the re-entering of recycled materials to the consumer market and, thus, contribute towards a circular economy. This is an area that requires further research due to the inhomogeneity of recycled materials. Therefore, the thermal and mechanical properties of virgin and recycled polypropylene/high-density polyethylene blends were investigated systematically. Differential scanning calorimetry concludes that both the recycled and virgin blends are immiscible. Generally, recycled blends have lower overall crystallinity and melting temperatures compared with virgin blends while, remarkably, their crystallisation temperatures are compared favourably. Dynamical mechanical analysis showed little variation in the storage modulus of recycled and virgin blends. However, the alpha and beta relaxation temperatures are lower in recycled blends due to structural deterioration. Deterioration in the thermal and mechanical properties of recycled blends is thought to be caused by the presence of contaminants and structural degradation during reprocessing, resulting in shorter polymeric chains and the formation of imperfect crystallites. The tensile properties of recycled blends are also affected by the recycling process. The Young's modulus and yield strength of the recycled blends are inferior to those of virgin blends due to the deterioration during the recycling process. However, the elongation at break of the recycled blends is higher compared with the virgin blends, possibly due to the plasticity effect of the low-molecular-weight chain fragments.

Thermal and mechanical characterization of composite materials from industrial plastic wastes and recycled nylon fibers for floor paving tiles application

Industrial plastic waste is growing globally at an alarming rate and environmental pollution from traditional landfill disposal and incineration treatments are of great concern. As a strategy to reduce plastic pollution, value-added composite materials from industrial plastic wastes reinforced with recycled nylon fibers for use in floor paving tile applications were developed. This is to address the disadvantages of existing ceramic tiles which are relatively heavy, brittle, and expensive. The plastic waste composite structures were produced via compression molding technique at an optimized randomly oriented constant fiber volume fraction of 50 wt% after the initial sorting, cleaning, drying, pulverizing, and melt-mixing. The molding temperature, pressure, and time for the composite's structures were 220 ℃, 65 kg.cm^-3, and 5 min respectively. The composites' thermal, mechanical, and microstructural properties were characterized in accordance with appropriate ASTM standards. From the results obtained, the differential scanning calorimetry (DSC) of mixed plastic wastes and nylon fiber wastes showed a processing temperature range of 130-180 ℃, and 250 ℃ respectively. Thermal degradation temperature (TGA) of the plastic and nylon fiber waste composites were stable above 400 ℃ with maximum bending strength, however, the reinforced plastic waste sandwiched composite structures had outstanding mechanical properties indicating unique characteristics suitable for floor paving tiles. Hence, the current research has developed tough and lightweight tiles composites that are economically viable, and their application will contribute to the development of the building and construction sectors thereby reducing about 10-15% of annual plastic waste generation and a sustainable environment.

WILL WE BE ABLE TO USE RECYCLED PLASTICS OR SHALL WE DECIDE FOR PACKAGING FREE PRODUKCTION?

Recycled plastic and its use are imperative for preserving the environment, including proper plastic wash-out. Will we ever be able to push the Czech population and firms to use recycled material? Or is it happening spontaneously? A questionnaire created on Google Forms involves ten legislative and motivational questions comprising relevant data on the amount of plastic in municipal waste between 2010 and 2020 from the Czech Statistical Office. We found that the population understands the importance of using recycled material and recycled plastic without the government's impulse. Despite the high capital intensity, the state should impose taxes to protect the sustainable environment. We suggest a comprehensive and in-depth survey to acquire more accurate data.

Assessment of the Applicability of Selected Data Mining Techniques for the Classification of Mortars Containing Recycled Aggregate

The article contains the results of selected tests of physical and mechanical properties of mortars differentiated in terms of the binder used: cement, epoxy, epoxy modified with PET waste glycolysate and polyester. Each type of mortar was modified by partial (0-20% vol.) substitution of sand with an agglomerate made from waste polyethylene. The obtained results were used to build a database of mortar properties, which was then analyzed with the use of three different techniques of knowledge extraction from databases, i.e., cluster analysis, decision trees and discriminant analysis. The average results of the properties tested were compared, taking into account the type of mortar, indicating those with the most favorable parameters. The possibilities and correctness of mortar classification with the use of the indicated "data mining" methods were compared. The results obtained confirmed that it is possible to successfully apply these methods to the classification of construction mortars and then to propose mortars with such a composition that will guarantee that the composite will have the expected properties. Both the presented method of plastic waste management and the proposed statistical approach are in line with the assumptions of the currently important concept of sustainable development in construction.