Natural Fillers as Potential Modifying Agents for Epoxy Composition: A Review

Abstract

Epoxy resins as important organic matrices, thanks to their chemical structure and the possibility of modification, have unique properties, which contribute to the fact that these materials have been used in many composite industries for many years. Epoxy resins are repeatedly used in exacting applications due to their exquisite mechanical properties, thermal stability, scratch resistance, and chemical resistance. Moreover, epoxy materials also have really strong resistance to solvents, chemical attacks, and climatic aging. The presented features confirm the fact that there is a constant interest of scientists in the modification of resins and understanding its mechanisms, as well as in the development of these materials to obtain systems with the required properties. Most of the recent studies in the literature are focused on green fillers such as post-agricultural waste powder (cashew nuts powder, coconut shell powder, rice husks, date seed), grass fiber (bamboo fibers), bast/leaf fiber (hemp fibers, banana bark fibers, pineapple leaf), and other natural fibers (waste tea fibers, palm ash) as reinforcement for epoxy resins rather than traditional non-biodegradable fillers due to their sustainability, low cost, wide availability, and the use of waste, which is environmentally friendly. Furthermore, the advantages of natural fillers over traditional fillers are acceptable specific strength and modulus, lightweight, and good biodegradability, which is very desirable nowadays. Therefore, the development and progress of “green products” based on epoxy resin and natural fillers as reinforcements have been increasing. Many uses of natural plant-derived fillers include many plant wastes, such as banana bark, coconut shell, and waste peanut shell, can be found in the literature. Partially biodegradable polymers obtained by using natural fillers and epoxy polymers can successfully reduce the undesirable epoxy and synthetic fiber waste. Additionally, partially biopolymers based on epoxy resins, which will be presented in the paper, are more useful than commercial polymers due to the low cost and improved good thermomechanical properties.

A Method of Managing Waste Oak Flour as a Biocomponent for Obtaining Composites Based on Modified Soybean Oil

“…The parquet flooring post-production wood flour was applied as reinforcement for epoxy resins based on a polyaddition product of epoxidized soybean oil and bisphenol-A. As presented within this manuscript, previous studies belonging to a wide variety of application-related research focused on the utilization of green fillers such as post-agricultural waste powder, grass fibers, bast/leaf fibers, and other natural fibers as reinforcement for both synthetic and bio-based epoxy resins [ 42 , 59 , 60 ]. The search for the possibility of additional uses continues because the management of waste or post-production particles of natural origin is environmentally friendly due to their sustainability, low cost, and wide availability.…”

Effect of Prosopis Juliflora Thorns on Mechanical Properties of Plastic Waste Reinforced Epoxy Composites

“…Epoxies have features that distinguish them from other resins, and adjustments can be made to meet our specifications. Epoxies have superior mechanical qualities, including increased thermal stability, wear and chemical resistance, and resistance to ageing caused by environmental factors [ 22 ]. In order to improve a composite’s specific characteristics and traits, fillers are incorporated into the material.…”

“…Recent research has concentrated on green fillers such as date seed powders, coconut and cashew nut shell powders, and rice and maize husks. Natural fibers and fillers are used in composites because they are inexpensive, widely available, biodegradable, recyclable, and lightweight [ 22 ]. Researchers are becoming more interested in starch-based bioplastics due to their environmentally beneficial characteristics.…”

Recent Advances in Development of Waste-Based Polymer Materials: A Review

“…The green nature of epoxy resins can also be enhanced by modifying them with fillers [150]. The results of recent research on epoxy resins modified with lignin [151], nanocellulose [152], hemp fibers [153], as well as industrial waste [154] indicated that this trend should develop in the near future.…”