Mechanical and structural properties of a novel melt processed PET–hemp composite: Influence of additives and fibers concentration

Abstract

The mechanical and structural properties of novel melt processed poly-ethylene terephthalate (PET)-hemp fiber composites for engineering applications were investigated. First, four reinforcement formulations were compared with the PET modified with poly-epsilon-caprolactone: hemp, Clay/hemp, pyromellitic dianhydride/hemp and glycidyl methacrylate/hemp. Next, the effect of hemp fibers concentration as well as the effect of heat treatment was analyzed. A significant difference was observed in the mechanical and structural properties of the composites. Moreover, we observed a good fiber–matrix interface without the use of a coupling agent, particularly in the absence of additives. Our data suggest that a careful trade-off between the additives, the hemp fiber concentration and the desired engineering applications is key requirement for the applications of high melting polymers-reinforced with natural fibers.

Investigation of the thermostability of poly(ethylene terephthalate)–hemp fiber composites: Extending natural fiber reinforcements to high‐melting thermoplastics

“…In this regard, for all of the applied heating rates, the E a of the second thermodegradation step increased with the fiber concentration until a maximum value was reached; this was followed by a gradual decrease. Such behavior was similar to the variation of the elastic modulus of the same formulations, which were reported in a previous work.…”

“…Furthermore, the data suggested a lower moisture absorption by the composite formulations; this was either due to the hemp fibers’ alkaline treatment or possible hydrogen bonding between the hydroxyl groups of the fibers and the carbonyl groups of PET. The latter hypothesis, which was verified earlier with the mechanical properties of the investigated composites, was also the motivation for the processing without the use of coupling agents.…”

“…The thermodegradation of natural fibers has a strong effect on both composites’ processing and their optimal applications because of the crystallization process. In fact, it has been reported that both the presence of natural fibers and the application of heat‐treatment operations enhanced the crystallization of biocomposite materials. This yielded a significant increase in their elastic moduli and a drastic reduction in their elongation at break.…”

Effect of processing temperatures on the thermal and mechanical properties of leather waste-ABS composites

“…Among the findings reported so far on natural fibre reinforced high temperature engineering plastics such as date palm leaf fibre/recycled poly(ethylene terephthalate), PET/Hemp, Jute fabric/polyamide and empty fruit bunch fibre/recycled poly(ethylene terephthalate), it was observed that the processing temperature of the natural fibre reinforced thermoplastics is highly dependent on the thermal degradation temperature of the natural fibres since the maximum processing temperature for natural cellulose-based fibres occurs at around 200°C. [1][2][3][4] Above this temperature, there is usually thermal degradation of natural fibres and consequently the decrease in mechanical properties of the resultant composite. [5][6][7] As a result, other natural fibre/fabric such as leather is being considered.…”

Development of sustainable biodegradable lignocellulosic hemp fiber/polycaprolactone biocomposites for light weight applications

“…These properties include, but are not limited to, thermal degradation kinetics [27], mechanical (elastic modulus, tensile strength and modulus), thermo-physical (degradability) and structural [28], among others as well as cyclic and creep [29] and mechanical (3-pont flexural and monotonic tensile) [30]. For examples, the experimental work carried out by Talla et al [31] highlighted the effects of hemp fiber reinforcement on the mechanical and structural properties of polyethylene terephthalate (PET)-hemp fiber composite samples. They concluded that addition of additives increased the mechanical properties (elastic modulus and strain at break) of the concerned composite samples.…”