Characterization of recycled and virgin polyethylene terephthalate composites reinforced with modified kenaf fibers for automotive application

Abstract

The current research has produced engineering plastics composite for automotive applications using waste recycled plastic recycled polyethylene terephthalate (RPET) bottles as the matrix and compounded with chemically modified natural kenaf fibers in comparison with virgin polyethylene terephthalate (PET) composites under the same processing conditions. Kenaf fibers were surface modified by alkali and epoxy coating treatment methods. The waste RPET bottles which were mechanically recycled were pulverized using a 5 mm mesh size aperture into flakes and melt‐mixed with 10 wt% of short kenaf fibers in a twin‐screw extruder and compression‐molded at 240°С optimized temperature. Mechanical and thermal analyses were performed on both RPET, virgin PET (VPET), and their constituent kenaf composites. Scanning electron microscopy (SEM) was carried out to assess the composite's morphological characteristics. The results show that both treated (TKF/RPET and TKF/VPET) composites gave higher mechanical properties compared to untreated (KF/RPET and KF/VPET) composites. RPET and its constituent composites show higher impact properties than VPET composites. However, the tensile and flexural strength of VPET composites was higher than that of recycled RPET composites. RPET and VPET showed melting peak temperatures of 252.9°C and 245.8°C respectively. Both treated TKF/RPET and TKF/VPET composites were more thermally stable and decomposed at higher temperatures compared to the untreated composites. The SEM results for both treated composites showed a strong fiber/matrix adhesion with no clear evidence of fiber degradation as compared to untreated composites. It can be concluded that RPET possessed similar thermal properties compared to its virgin counterpart and can serve as a substitute for virgin PET in the composite formulation.

Effects of high‐temperature optimization and resin coating treatment on the mechanical, thermal, and morphological properties of natural kenaf fiber‐filled engineering plastic composites

“…Hence, the increase in onset degradation temperature for CKF is an indication of delayed degradation or resistance to thermal degradation which agrees with other studies on natural fiber composites. [ 28 ]…”

“…Hence, the increase in onset degradation temperature for CKF is an indication of delayed degradation or resistance to thermal degradation which agrees with other studies on natural fiber composites. [28] From the TGA results obtained for the 250 and 260 C processing temperatures as in Figure 4B,C, and Table 1C,D, It could be observed in Figure 4B for processing temperature of 250 C, that uncoateduntreated KF-PET composites showed an Onset degradation of 400.9 C and decomposed at 448.6 C temperatures, whereas, in comparison, all coated composites were thermally stabled above 400 C with higher decomposition temperatures of (above 450 C) 454.2 and 457.6 C for CKF-PET and CTKF-PET respectively. This further substantiates the TGA results obtained for composites that were processed at a temperature of 240 C with the effects of epoxy coating treatment in enhancing the thermal degradation resistance of natural fiber in engineering plastic composites at high temperatures.…”

“…In a separate study, composites of both recycled and virgin poly (ethylene terephthalate) with modified natural KF were reported, [ 28 ] and was further established that thermoset epoxy surface coating treatment can prevent KF degradation at elevated temperatures. It was also found that recycled PET had comparable thermal properties as the virgin ones with the potential to be used as a replacement for virgin PET in composite manufacturing.…”

Effect of glass fiber loading and reprocessing cycles on the mechanical, thermal, and morphological properties of isotactic polypropylene composites

“…2 Plastic recycling has been defined as a method targeted at recovering reusable parts and processable materials. [3][4][5] To lessen environmental concerns and obtain sustainable solutions, the reuse and recycling of components from plastic are very essential. The recycling of plastics has been classified into three different routes known as primary, secondary, and tertiary recycling processes.…”

“…Plastic recycling has been defined as a method targeted at recovering reusable parts and processable materials 3–5 . To lessen environmental concerns and obtain sustainable solutions, the reuse and recycling of components from plastic are very essential.…”