This review intends on chemical recycling of the carbon fiber-reinforced epoxy resin composites (CFREPs) for future applications. Many recycling methods were investigated such as chemical, ...solvolysis, glycolysis and hydrolysis. Mechanical recycling produces poor-quality carbon fibers (CFs) which exhibits short length and lower tensile modulus, whereas thermal recycling process, especially pyrolysis, gives fibers with char formation on the surface. Among them, the most promising is chemical recycling, as CFs can be recycled from CFREPs very easily and in most environmentally favorable conditions. Additionally, recent approach of chemical recycling with supercritical fluids in which no mechanical degradation occurs was also reviewed. It comes under green reaction media as they are easily available, less expensive, less toxic, soluble in different organic and inorganic compounds, and distillation process can be introduced to recycle afterward also. An economical approach of chemically recycling thermoset epoxy resin is also considered. Various greener approach methods of chemical recycling and its advantages over various other recycling processes were discussed in details, and finally structural and nonstructural applications of recycled carbon fibers are discussed.
The petroleum based diglycidyl ether of bisphenol A (DGEBA) epoxy resin is one of the most extensively used epoxy resins for various industrial applications such as paints, coatings, adhesives, and ...structural applications, owing to its excellent mechanical and thermal properties, low curing shrinkage, and good chemical resistance. However, the serious drawbacks in terms of brittleness or poor fracture energy significantly restricted its extensive utilization. Various renewable resources based flexible chains were used to blend with DGEBA for toughening and to significantly improve the fracture properties without sacrificing the mechanical properties. This review mainly focuses on toughening of DGEBA with various renewable polymers and the effect of its concentration on its toughening mechanism.
The objective of this work is to enhance the toughness of In the current study, inherently brittle polylactic acid (PLA) has been toughened using a biobased polyester without compromising the ...biocompatibility, renewability, strength and thermal properties of PLA. For this purpose, biodegradable Renewable resources resource based flexible aliphatic polyester (BBPE) has been synthesized and the same has been confirmed by FTIR and
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H NMR. Melt blending of BBPE elastomer with PLA in presence of free radical initiator dicumyl peroxide (DCP) leads to the development of crosslinked PLA/BBPE (PBE) blends of tunable properties. Additionally, the mechanical, morphological, thermal, crosslink density and water absorption behaviour of PBE blends were explored. It was observed that the synthesized biobased BBPE elastomers contribute to toughening of the PLA matrix consequently, improving the its impact strength and elongation at break. of the blend
Sustainable and biocompatible novel lactic acid based bioelastomer (LBPE) was synthesized by polycondensation process which has been confirmed by FTIR and
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H NMR. Owing to the resemblances in the ...lactate structures of polylactic acid (PLA) and LBPE, the synthesized LBPE bioelastomers can act as an excellent PLA toughener in presence of free radical initiator dicumyl peroxide (DCP). The mechanical, morphological and thermal were investigated. Chemical crosslinks endow the LBPE with relatively high elasticity and environmental stability which ultimately enhances the mechanical properties of PLA matrix.
The current work deals with enhancing the compatibility between thermoplastic starch (TPS) and polylactic acid (PLA) blends. TPS was initially modified with methylene diphenyldiisocyanate ...(MDI)/epoxidized soybean oil (ESO) to reduce its hydrophilic nature. The effect of MDI/ESO incorporation on the properties of PLA/TPS blend was evaluated by employing thermal, mechanical, morphological and water absorption studies. Morphological studies showed that in comparison to TPS, TPS modified by MDI and ESO were uniformly dispersed within the PLA matrix and exhibited higher impact energy as compared with neat PLA.
To overcome the limitations of polylactic acid, alterations are needed to enhance its toughness, to improve handling and for various applications. Extensive studies were reported, mainly in the area ...of blends with renewable resource polymer blends. Better phase dispersion between the blend materials is achieved either by reactive mixing of the two components or by incorporation of a block copolymer compatibilizer, finally showing highly enhanced property. In this article, the recent research progress of different toughening processes of PLA via blending is reviewed and a detailed understanding about toughening of PLA using biodegradable or renewable polymers has been established.
