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
With respect to the explosion of single-use plastic packaging consumption during the COVID-19 pandemic, environmentally friendly substitutes are critically needful for sustainable development. Therefore, the present work focuses on the functional properties of bioplastic blends prepared through hot compressing molding of thermoplastic starch (TPS) and spent coffee grounds (SCG) in different ratios (0%–20% SCG) as the potential features of SCG were extensively employed in biocomposites for the first time. The insertion of dark brown SCG into TPS hindered UV transmission by 100% at 320 nm and 99.2% at 400 nm. Moreover, the samples with 15% and 20% SCG induced a surge in radical scavenging activity from 7.95% to over 92% at a concentration of 0.1 g/ml owing to the rich source of antioxidants in SCG. The lignin component and high carbon content also improved the thermal performance of TPS/SCG blends, enhancing thermal stability, delaying onset and maximum degradation temperatures, and achieving the HB rating in the UL-94 test. Compared to a pure TPS matrix, TPS blends incorporating up to 10% SCG exhibited improvement in elastic modulus without deterioration of tensile strength. © 2022 Society of Plastics Engineers.