ABSTRACT
Advancements in polymer science and engineering have helped the scientific community to shift its attention towards the use of environmentally benign materials for reducing the environmental impact of conventional synthetic plastics. Biopolymers are environmentally benign, chemically versatile, sustainable, biocompatible, biodegradable, inherently functional, and ecofriendly materials that exhibit tremendous potential for a wide range of applications including food, electronics, agriculture, textile, biomedical, and cosmetics. This review also inspires the researchers toward more consumption of biopolymer-based composite materials as an alternative to synthetic composite materials. Herein, an overview of the latest knowledge of different natural- and synthetic-based biodegradable polymers and their fiber-reinforced composites is presented. The review discusses different degradation mechanisms of biopolymer-based composites as well as their sustainability aspects. This review also elucidates current challenges, future opportunities, and emerging applications of biopolymeric sustainable composites in numerous engineering fields. Finally, this review proposes biopolymeric sustainable materials as a propitious solution to the contemporary environmental crisis. © 2022 Elsevier Ltd.
ABSTRACT
The crucial role of face masks is highlighted in our day-to-day life during the COVID-19 pandemic. Polypropylene (PP)-based disposable face masks are widely used to hold back viral transmission. The discarded masks can create a huge burden of contamination on the environment. The purpose of this work is to recycle and reuse discarded masks to reduce environmental pollution. A simple and innovative technique to recycle surgical masks into composites of higher mechanical strength and antimicrobial properties is explored to reuse in packaging materials and cutleries. The surgical masks composed of PP fibers are recycled to use as a matrix material to reinforce with sisal and hemp fibers. The hot compression molding technique is used to sandwich the PP masks with natural fibers. The tensile strength of the composites is remarkably increased by 197% and 305% for sisal fiber composites and hemp fiber composites, respectively. The tensile elongation also increased to 574% for sisal fiber composites. The resulting composites exhibit notable antimicrobial properties against Staphylococcus aureus, a pathogen responsible for common staphylococcal food poisoning. The composites are found to be suitable to use as food contact cutleries and packaging materials.
ABSTRACT
In recent years, an unprecedented increase in the development of products and technologies to protect the human being has been observed. Now, more than ever, the world population is exposed to several threats, harmful to their well-being and health. Chemical and biological hazardous agents stand out as one of the biggest threats, not only for the military forces, but also for the civilians. Consequently, it's essential to develop personal protective systems that are able to protect their user, not only passively, but actively, being able to detect, adsorb, degrade and decontaminate pesticides, pollutants, microorganisms and most importantly: chemical/biological warfare agents. One recent strategy for the development of active fibrous structures with improved functions and new properties is their functionalization with nanoparticles (NPs), especially metal oxides. Although their known effectiveness in the decomposition of harmful agents, the NPs could also include other functionalities in the same structure using low quantities of material, without adding extra weight, which is of huge importance for a soldier in the battlefield. The use of natural fibers as the substrate is also very interesting, since this material is a much sustainable alternative when compared to synthetic ones, also providing excellent properties.