The present work deals with investigating the influence of microwave power on mechanical properties of 20 wt.% coir reinforced high-density polyethylene (HDPE) composites. Chopped coir/HDPE composites were fabricated using various microwave power levels (360 W, 540 W, 720 W and 900 W). The XRD analysis of the specimens reveals that crystallinity index in various specimens was in the range of 79.54% to 84.59%. The specimen cured at 360 W exhibited a maximum tensile strength of 29.5 ± 1.5 MPa, which is 28.26% greater than composite cured at 900 W (23 ± 1.5 MPa). Flexural strength of specimen cured at 360 W was maximum (37.74 ± 2 MPa).

In the present work, polypropylene (PP)- and polyethylene (PE)-based composites were cured using microwave energy with 15% weight percentage of jute and kenaf fibres. The detailed mechanism of microwave curing of the composites has been discussed with suitable illustrations. The mechanical characterization of the microwave-cured composites was carried out using various tests. The scanning electron microscope (SEM) fractographs were used to study the mechanisms of failure. The ultimate tensile strength of various microwave-cured composites was in the range of 44–50 MPa. The interlaminar shear strength of the PP-based composites was 62% higher than the PE-based composites. The impact energy of the microwave-cured composites was in the range of 18–24 kJ. The mechanical performance of the microwave-cured composites was comparable to the composites obtained through traditional manufacturing routes.

Always, the environment in which humans live needs to be saved from various calamities, and one such calamity is usage of petroleum-based products. Petroleum-based products are derived from various synthetic processes that adversely affect the environment. It may not reflect immediately, but it affects in the near future. They are non-environmentally friendly and cannot progress toward the sustainability factor. The alternative to metallic or synthetic fibers is natural fibers that are derived from plant sources. The demerits of using natural fiber is its less strength; however, this strength can be enhanced by incorporating it as a strengthening component in polymer matrix composite (PMC) materials. Still, the major advantage of using metal is its ability to withstand higher temperatures, whereas PMCs fail in these characteristics. The use of nanoparticles as fillers in the natural fiber–reinforced PMCs is a probable solution to the above problem. This review assesses the thermal characteristics of various nanoparticle-filled natural fiber–based polymer composites. It can be seen from most of the research that the filled polymer composites exhibit better thermal behavior compared with non-filled polymer composites. This consolidation would be useful for researchers to further accelerate their research in this domain.

Additive flame retardant offers several advantages in terms of formulation, improved performance and reduced environmental impact. These additives result in superior thermal management and the delay of thermal runaway events which ensures safety as well as durability. This review underlines the importance of appropriate additive flame retardant selection such as zinc borate, alumina and other inorganic flame retardants within the epoxy matrix. This study sets itself apart by introducing modeling and simulation techniques and comparing various additive flame retardants in terms of enhancing flame retardant properties, tensile strength and toughness of the composite. It also includes a more in-depth examination of manufacturing processes, burning mechanism and stabilization of polymer composite. The importance of conducting characterization such as cone calorimetry, UL-94 test is summarized for validating the desired flame retardant properties. Furthermore, it addresses the principal challenges and offers strategies to overcome these challenges based on the current research landscape.