Plastics materials which are used in our daily life especially for packaging applications are derived from petrochemicals. Though these plastic materials satisfy the required properties of packaging materials in terms of strength, water resistance, and durability, they are not biodegradable and stay in landfills for plenty of years. This causes serious environmental threat and pollution. Owing to this, biodegradable plastics have been emerged as an alternative to conventional plastics. However, most of the biodegrade plastics are dependent on forest reserves even some may affect food supply. Nevertheless, agar and polyvinyl alcohol (PVA) neither causes deforestation nor affect the food stock. Though agar and PVA neither causes deforestation nor affect the food supply, they have high water absorption and a moderate tensile strength. This restricts the use of these polymers for applications. Researchers have used physicochemical modification methods to improve the properties of biodegradable polymers with due attention of agar and PVA. This review presents the basics of polymers, biodegradable polymers, chemistry of biodegradation, environmental impacts of biodegradable polymers, and the physicochemical modification of biodegradable polymers with a special focus of agar and PVA.

The field of biomimetic and bioinspired materials has progressed rapidly by drawing inspiration from nature's intricate structures and multifunctional systems in order to address pressing challenges in modern engineering. This review critically examines the mechanical performance of these materials, focusing on their hierarchical design principles, synthesis strategies, and versatility of application. Natural exemplars such as nacre, spider silk, and bone are emphasized, as their structural efficiency and functional adaptability have informed the development of synthetic analogues with superior strength, toughness, flexibility, and lightweight characteristics. The review also highlights advanced fabrication methods, such as additive manufacturing and precision chemical synthesis, which have enabled researchers to replicate the complexity of nature with ever‐greater accuracy. Key case studies demonstrate how bioinspired strategies have been translated into high‐performance materials for use in the aerospace, construction, and biomedical sectors. The review also discusses challenges related to scalability, reproducibility, and industrial integration. Finally, the review outlines emerging interdisciplinary approaches that are set to further enhance the mechanical properties and practical relevance of biomimetic materials, establishing them as transformative solutions for the next generation of engineering systems.

Plastics are ubiquitous in our daily life. However, the use of petrochemical-based plastic as packaging materials causes the depletion of non-renewable resources, thereby leading to an increase in oil prices and economic crises. Moreover, these petrochemical plastics raise the issue of environmental pollution due to their non-biodegradability. Owing to this, there is a need to develop an alternative biodegradable and eco-friendly packing material. Agar, which is extracted from seaweeds, is one of the abundantly available polymers. However, moderate tensile strength and thermal stability restrict its application. As a step forward, agar/reduced graphene oxide (RGO) composites were prepared by in situ reduction of GO in the polymer matrix. The tensile strength of the composite was found to increase by 55 at 2 RGO loading. The electrical conductivity and thermal properties of the composite were also improved. The presence of conductivity suggested that apart from packaging, agar/RGO composites can also have potential applications as capacitor plates creating a supercapacitor and as electric field-induced wound healing material.

Rice straw represents a plentiful agricultural by-product that remains largely underexploited, particularly for composite reinforcement, due to poor fiber-matrix interactions and its high amorphous fraction. In this study, environmentally benign surface modification strategies were explored to ensure better mutual performance of rice-straw grains with an epoxy pattern. Four activation approaches were evaluated: ultrasonic treatment (P1), ultrasonic assisted with sodium carbonate (P2), plasma exposure (P3), and a combined Na₂CO₃-plasma sequence (P4). Fibers were processed using 5% w/v Na₂CO₃ solution and low-pressure plasma at 13.56 MHz, followed by fabrication of epoxy composites. The materials were examined through several analytical methods, including flexural evaluation (ASTM D790), FTIR spectroscopy, SEM-EDX imaging, XRD diffraction, TGA/dTG thermal analysis, and BET surface analysis. An overall enhancement in mechanical characteristics was detected as the degree of treatment increased. Sample P1 had a flexural durability of approximately 109.1 MPa, while sample P4 showed elasticity at 162.0 MPA and the range of modalities in terms of their articulation was expanded by 5.625 GPa (passive modulus) from 3.709 GPa when tested against other methods. SEM micrographs revealed remarkable surface alterations, such as a 131% rise in micro-texture roughness (from 0.344 to 0.796), resin deposition reaching 90.8%, a 72% decline in pore or void fraction (from 3.319% to 0.917%), and an 84% reduction in silica or ash residues. XRD profiles showed more pronounced cellulose-I reflections at 15.7°, 22.6°, and 34.6°, alongside the suppression of the amorphous halo (18–20°), signifying increased crystallinity, particularly in P4 fibers. TGA results demonstrated reduced char residue and higher, sharper Tmax peaks, confirming improved thermal stability. Among the treatments, the Na₂CO₃-assisted plasma approach (P4) provided the most substantial enhancement, offering a scalable and sustainable method to upgrade rice-straw fibers for structural composite applications.

Composite materials are one of the fastest growing when compared with metal, ceramic, and polymer due to their high specific strength, stiffness, and versatile application in various fields. This study aimed to develop an ox bone powder and bamboo fiber-reinforced hybrid epoxy composite for stock and bumper applications and investigate the effect of the reinforcements on the composite’s mechanical properties. The reinforcements used in this work were random orientations of animal bone (ox) powder of 75 microns and bamboo fiber. The matrix used for this work was epoxy resin. Composite materials were prepared using the hand layup method with a 40% weight fraction of reinforcement (bone powder and bamboo fiber) and a 60% weight fraction of epoxy resin matrix. Five different combinations of bone powder and bamboo fiber with a fixed amount of epoxy resin were used for this work. The combinations of bamboo fiber and bone powder were: 40% bamboo fiber with 0% bone powder; 30% bamboo fiber with 10% bone powder; 20% bamboo fiber with 20% bone powder; and 0% bamboo fiber with 40% bone powder. The mechanical properties studied were compressive strength, impact strength, and flexural strength. In addition, water absorption was studied for all combinations. The maximum results of the flexural and impact strengths were 278.91 MPa and 7.5 J/m, respectively, at a 0:40 (bone powder: bamboo fiber) composite. The maximum compressive strength and the lowest absorption obtained were 283.3 MPa and 1.05%, respectively, at the 40:0 (bone powder: bamboo fiber) composite. For the hybrid composite case, optimal flexural and impact strengths were 236.72 MPa and 6.66 J/m, respectively, and water absorption was 1.52% at 10:30 (bone powder: bamboo fiber). Since reasonable flexural strength, impact strength, and water absorption were obtained with the hybrid composite of 10:30 (bone powder: bamboo fiber), this combination of the hybrid composite is recommended for stock and bumper applications.