scholarly journals Effect of Halloysite Nanotube on Mechanical Properties, Thermal Stability and Morphology of Polypropylene and Polypropylene/Short Kenaf Fibers Hybrid Biocomposites

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4459 ◽  
Author(s):  
Piotr Franciszczak ◽  
Iman Taraghi ◽  
Sandra Paszkiewicz ◽  
Maksymilian Burzyński ◽  
Agnieszka Meljon ◽  
...  

In this article, the effect of the addition of halloysite nanotube (HNT) on the mechanical and thermal stability of polypropylene (PP) and PP/kenaf fiber biocomposites has been investigated. Different volume contents of HNTs ranging from 1 to 10 vol.% were melt mixed with PP and PP/kenaf fibers. The volume content of kenaf fibers was kept constant at 30%. The morphology of HNTs within the PP matrix has been studied via scanning electron microscopy (SEM). The morphological results revealed that HNT was uniformly dispersed in the PP matrix already at a low concentration of 1 and 2 vol.%. The mechanical properties of the manufactured nanocomposites and hybrid biocomposites such as Young’s modulus, tensile strength, elongation at break, flexural modulus, flexural strength, and notched Izod strength have been measured. The results show that Young’s modulus and strengths have been improved along with the addition of low content of HNTs. Moreover, the gain of notched Izod impact strength obtained by the addition of short kenaf fibers was maintained in hybrids with low concentrations of HNTs. Finally, the thermogravimetric analysis shows that at 10% and 50% weight loss, the thermal degradation rate of the PP and PP/kenaf biocomposites decreased by the addition of HNTs.

2015 ◽  
Vol 35 (3) ◽  
pp. 257-266 ◽  
Author(s):  
Rahim Eqra ◽  
Kamal Janghorban ◽  
Habib Daneshmanesh

Abstract Because of extraordinary physical, chemical and mechanical properties, graphene nanosheets (GNS) are suitable fillers for optimizing the properties of different polymers. In this research, the effect of GNS content (up to 1 wt.%) on tensile and flexural properties, morphology of fracture surface, and toughening mechanism of epoxy were investigated. Results of mechanical tests showed a peak for tensile and flexural strength of samples with 0.1 wt.% GNS such that the tensile and flexural strength improved by 13% and 3.3%, respectively. The Young’s modulus and flexural modulus increased linearly with GNS content, although the behavior of the Young’s modulus was more remarkable. Morphological investigations confirmed this behavior because the GNS dispersion in the epoxy matrix was uniform at lower contents and agglomerated at higher contents. Finally, microscopical observation showed that the major toughening mechanism of graphene-epoxy nanocomposites was crack path deflection, which changed the mirror fracture surface of the pure epoxy to rough surface.


2021 ◽  
Vol 32 (2) ◽  
pp. 87-104
Author(s):  
Pui-Voon Yap ◽  
Ming-Yeng Chan ◽  
Seong-Chun Koay

This research work highlights the mechanical properties of multi-material by fused deposition modelling (FDM). The specimens for tensile and flexural test have been printed using polycarbonate (PC) material at different combinations of printing parameters. The effects of varied printing speed, infill density and nozzle diameter on the mechanical properties of specimens have been investigated. Multi-material specimens were fabricated with acrylonitrile butadiene styrene (ABS) as the base material and PC as the reinforced material at the optimum printing parameter combination. The specimens were then subjected to mechanical testing to observe their tensile strength, Young’s modulus, percentage elongation, flexural strength and flexural modulus. The outcome of replacing half of ABS with PC to create a multi-material part has been examined. As demonstrated by the results, the optimum combination of printing parameters is 60 mm/s printing speed, 15% infill density and 0.8 mm nozzle diameter. The combination of ABS and PC materials as reinforcing material has improved the tensile strength (by 38.46%), Young’s modulus (by 23.40%), flexural strength (by 23.90%) and flexural modulus (by 37.33%) while reducing the ductility by 14.31% as compared to pure ABS. The results have been supported by data and graphs of the analysed specimens.


Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2578
Author(s):  
Junghoon Kim ◽  
Donghwan Cho

Waste Expanded polypropylene (EPP) was utilized as recycled matrix for kenaf fiber-reinforced polypropylene (PP) composites produced using chopped kenaf fibers and crushed EPP waste. The flexural properties, impact strength, and heat deflection temperature (HDT) of kenaf fiber/PP composites were highly enhanced by using waste EPP, compared to those by using virgin PP. The flexural modulus and strength of the composites with waste EPP were 98% and 55% higher than those with virgin PP at the same kenaf contents, respectively. The Izod impact strength and HDT were 31% and 12% higher with waste EPP than with virgin PP, respectively. The present study indicates that waste EPP would be feasible as recycled matrix for replacing conventional PP matrix in natural fiber composites.


2018 ◽  
Vol 89 (9) ◽  
pp. 1782-1791 ◽  
Author(s):  
Jong Sun Jung ◽  
Kyung Hun Song ◽  
Seong Hun Kim

The mechanical properties and biodegradability of retted kenaf and modified starch composites fabricated by adding enzyme-retted kenaf as a filler and poly(vinyl alcohol) (PVA), poly(ethylene glycol), or glycerol as a plasticizer are compared with those of the NaOH-retted counterparts fabricated under identical conditions. In the case of enzyme retting, the composite treated with the PVA plasticizer was deemed the most appropriate for achieving optimal tensile strength, flexural strength, and flexural modulus. Further, the retting treatment, the length of the kenaf fiber, the type of treatment (single- or double-sided), and the adhesion force at the interface significantly affect the mechanical properties of the composites. According to the aerobic biodegradability assessment in natural reclamation conditions, the modified starch composite fabricated using 50-mm-long enzyme-retted kenaf fibers as the filler and double-side treated with PVA plasticizer showed a biodegradation rate of 80% or higher after 80 days.


Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1551
Author(s):  
Camelia Gabor ◽  
Daniel Cristea ◽  
Ioana-Laura Velicu ◽  
Tibor Bedo ◽  
Andrea Gatto ◽  
...  

The development of novel Ti-based amorphous or β-phase nanostructured metallic materials could have significant benefits for implant applications, due to improved corrosion and mechanical characteristics (lower Young’s modulus, better wear performance, improved fracture toughness) in comparison to the standardized α+β titanium alloys. Moreover, the devitrification phenomenon, occurring during heating, could contribute to lower input power during additive manufacturing technologies. Ti-based alloy ribbons were obtained by melt-spinning, considering the ultra-fast cooling rates this method can provide. The titanium alloys contain in various proportions Zr, Nb, and Si (Ti60Zr10Si15Nb15, Ti64Zr10Si15Nb11, Ti56Zr10Si15Nb19) in various proportions. These elements were chosen due to their reported biological safety, as in the case of Zr and Nb, and the metallic glass-forming ability and biocompatibility of Si. The morphology and chemical composition were analyzed by scanning electron microscopy and energy-dispersive X-ray spectroscopy, while the structural features (crystallinity, phase attribution after devitrification (after heat treatment)) were assessed by X-ray diffraction. Some of the mechanical properties (hardness, Young’s modulus) were assessed by instrumented indentation. The thermal stability and crystallization temperatures were measured by differential thermal analysis. High-intensity exothermal peaks were observed during heating of melt-spun ribbons. The corrosion behavior was assessed by electrocorrosion tests. The results show the potential of these alloys to be used as materials for biomedical applications.


2019 ◽  
pp. 089270571987823 ◽  
Author(s):  
Md RH Mazumder ◽  
F Numera ◽  
A Al-Asif ◽  
M Hasan

Present research investigates the effect of bentonite clay and polypropylene (PP) matrix on the properties of silk and glass fiber hybrid composites. Three types of composite were prepared with 10 wt% silk and fiber at 1:1 ratio using hot press machine. In two composites commercial and recycled PP were used as matrix, while in third composite bentonite clay was added to silk and glass-reinforced commercial PP. Mechanical (tensile, flexural, impact, and hardness) tests, water absorption test, and thermogravimetric analysis were subsequently conducted. Tensile strength, flexural modulus, and hardness decreased, whereas Young’s modulus, impact strength, water absorption, and thermal stability increased with the addition of bentonite clay. On the other hand, change of matrix from commercial PP to recycled PP increased Young’s modulus, flexural strength, impact strength, and thermal stability and decreased tensile strength, flexural modulus, and hardness.


Nanomaterials ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 940 ◽  
Author(s):  
Mualla Öner ◽  
Gülnur Kızıl ◽  
Gülşah Keskin ◽  
Celine Pochat-Bohatier ◽  
Mikhael Bechelany

The thermal and mechanical properties of poly(3-hydroxybutyrate-co-3-hydroxyvalerate, PHBV) composites filled with boron nitride (BN) particles with two different sizes and shapes were studied by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), thermal gravimetric analysis (TGA) and mechanical testing. The biocomposites were produced by melt extrusion of PHBV with untreated BN and surface-treated BN particles. Thermogravimetric analysis (TGA) showed that the thermal stability of the composites was higher than that of neat PHBV while the effect of the different shapes and sizes of the particles on the thermal stability was insignificant. DSC analysis showed that the crystallinity of the PHBV was not affected significantly by the change in filler concentration and the type of the BN nanoparticle but decreasing of the crystallinity of PHBV/BN composites was observed at higher loadings. BN particles treated with silane coupling agent yielded nanocomposites characterized by good mechanical performance. The results demonstrate that mechanical properties of the composites were found to increase more for the silanized flake type BN (OSFBN) compared to silanized hexagonal disk type BN (OSBN). The highest Young’s modulus was obtained for the nanocomposite sample containing 1 wt.% OSFBN, for which increase of Young’s modulus up to 19% was observed in comparison to the neat PHBV. The Halpin–Tsai and Hui–Shia models were used to evaluate the effect of reinforcement by BN particles on the elastic modulus of the composites. Micromechanical models for initial composite stiffness showed good correlation with experimental values.


e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Shahryar Jafari Nejad ◽  
Seyed Javad Ahmadi ◽  
Hossein Abolghasemi ◽  
Ahmad Mohaddespour

AbstractIn this research, the melt blending technique was used to prepare various polypropylene (PP) based nanocomposites. A commercial organoclay (denoted 15A) served as the filler for PP matrix, and the maleic anhydride modified PP was used as compatibilizer. The specimens were subjected to electron beam (EB) irradiation. The purpose of the study focuses on the influences of EB irradiation on the thermal stability and mechanical properties of the nanocomposites. The morphology of the nanocomposites was studied using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The XRD and SEM results showed that these nanocomposites are best described as intercalated systems. PP/Clay nanocomposites showed good thermal stability in the TGA analysis. TGA data at 500KGy showed that the EB irradiation has negative effect on thermal stability of the nanocomposites. Mechanical testing showed that the EB irradiation strongly influences the mechanical properties (tensile strength, Young’s modulus and hardness) of PP/Clay nanocomposites. The value of tensile strength decreases remarkably for all specimens with increasing irradiation dose up to about 550 KGy, but this reduction for nanocomposites with 3% clay is less than that of the pure PP/PP-g-MA blend. In higher irradiation doses, reduction in tensile strength of PP nanocomposites is less than that of the pure PP/PP-g-MA blend. Optimum irradiation dose of Young’s modulus for PP/Clay nanocomposites with 5% clay is 450 KGy. The hardness of the nanocomposites with 5% clay was found to decrease with increase in irradiation dose.


Foods ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 3043
Author(s):  
Isabel Bascón-Villegas ◽  
Mónica Sánchez-Gutiérrez ◽  
Fernando Pérez-Rodríguez ◽  
Eduardo Espinosa ◽  
Alejandro Rodríguez

Films formulated with polyvinyl alcohol (PVA) (synthetic biopolymer) were reinforced with lignocellulose nanofibres (LCNF) from residues of vegetable production (natural biopolymer). The LCNF were obtained by mechanical and chemical pre-treatment by 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO) and added to the polyvinyl alcohol (polymer matrix) with the aim of improving the properties of the film for use in food packaging. The mechanical properties, crystallinity, thermal resistance, chemical structure, antioxidant activity, water barrier properties and optical properties (transparency and UV barrier), were evaluated. In general, with the addition of LCNF, an improvement in the studied properties of the films was observed. In terms of mechanical properties, the films reinforced with 7% LCNF TEMPO showed the best results for tensile strength, Young’s modulus and elongation at break. At the same LCNF proportion, the thermal stability (Tmax) increased between 5.5% and 10.8%, and the antioxidant activity increased between 90.9% and 191.8%, depending on the raw material and the pre-treatment used to obtain the different LCNF. Finally, a large increase in UV blocking was also observed with the addition of 7% LCNF. In particular, the films with 7% of eggplant LCNF showed higher performance for Young’s modulus, elongation at break, thermal stability and UV barrier. Overall, results demonstrated that the use of LCNF generated from agricultural residues represents a suitable bioeconomy approach able to enhance film properties for its application in the development of more sustainable and eco-friendly food packaging systems.


2012 ◽  
Vol 488-489 ◽  
pp. 691-695
Author(s):  
Saowaroj Chuayjuljit ◽  
Thitima Rupunt

The focus of this study is to investigate the influences of ethylene octene copolymer (EOC) and carbon nanotubes (CNTs) on the mechanical properties (tensile and flexural properties) and thermal stability of polypropylene (PP)-based thermoplastic elastomer nanocomposites. The PP/EOC blends were prepared at two different weight ratios, 80/20 and 70/30 (w/w) PP/EOC, and each blend was compounded with a very low loading of CNTs (0.5-2 parts by weight per hundred of the PP/EOC resin). Both PP/EOC blends exhibited a higher elongation at break but a lower tensile strength, Young’s modulus and flexural strength as compared with those of the neat PP. However, the addition of CNTs caused a slightly change in the tensile strength and flexural strength but a more significant change in the Young’s modulus and elongation at break. The Young’s modulus and elongation at break of the PP/EOC blends were improved by filling with the appropriate loading of the CNTs. Thus, the combined use of EOC and CNTs can provide the balanced mechanical properties to the PP. Moreover, thermogravimetric analysis showed an improvement in the thermal stability of PP by the presence of both EOC and CNTs.


Sign in / Sign up

Export Citation Format

Share Document