scholarly journals Effects of Water and Chemical Solutions Ageing on the Physical, Mechanical, Thermal and Flammability Properties of Natural Fibre-Reinforced Thermoplastic Composites

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4581
Author(s):  
Baljinder K. Kandola ◽  
S. Ilker Mistik ◽  
Wiwat Pornwannachai ◽  
A. Richard Horrocks
Keyword(s):  
Salt Water ◽  
Flexural Modulus ◽  
Moisture Sorption ◽  
Natural Fibre ◽  
Thermoplastic Composites ◽  
Wool Fibre ◽  
Poly Lactic Acid ◽  
Natural Polymers ◽  
Chemical Solutions ◽  
Pp Composites

Biocomposites comprising a combination of natural fibres and bio-based polymers are good alternatives to those produced from synthetic components in terms of sustainability and environmental issues. However, it is well known that water or aqueous chemical solutions affect natural polymers/fibres more than the respective synthetic components. In this study the effects of water, salt water, acidic and alkali solutions ageing on water uptake, mechanical properties and flammability of natural fibre-reinforced polypropylene (PP) and poly(lactic acid) (PLA) composites were compared. Jute, sisal and wool fibre- reinforced PP and PLA composites were prepared using a novel, patented nonwoven technology followed by the hot press method. The prepared composites were aged in water and chemical solutions for up to 3 week periods. Water absorption, flexural properties and the thermal and flammability performances of the composites were investigated before and after ageing each process. The effect of post-ageing drying on the retention of mechanical and flammability properties has also been studied. A linear relationship between irreversible flexural modulus reduction and water adsorption/desorption was observed. The aqueous chemical solutions caused further but minor effects in terms of moisture sorption and flexural modulus changes. PLA composites were affected more than the respective PP composites, because of their hydrolytic sensitivity. From thermal analytical results, these changes in PP composites could be attributed to ageing effects on fibres, whereas in PLA composite changes related to both those of fibres present and of the polymer. Ageing however, had no adverse effect on the flammability of the composites.

scholarly journals Fully Biodegradable Composites: Thermal, Flammability, Moisture Absorption and Mechanical Properties of Natural Fibre-Reinforced Composites with Nano-Hydroxyapatite

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1145 ◽  
Author(s):  
Pooria Khalili ◽  
Xiaoling LIU ◽  
Zirui ZHAO ◽  
Brina Blinzler
Keyword(s):  
Mechanical Properties ◽  
Moisture Absorption ◽  
Flexural Modulus ◽  
Tensile Modulus ◽  
Natural Fibre ◽  
Poly Lactic Acid ◽  
Degradation Temperature ◽  
Conventional Film ◽  
Natural Fabrics ◽  
Burn Rate

Natural fibre-reinforced poly(lactic acid) (PLA) laminates were prepared by a conventional film stacking method from PLA films and natural fabrics with a cross ply layup of [0/90/0/90/0/90], followed by hot compression. Natural fibre (NF) nano-hydroxyapatite (nHA) filled composites were produced by the same manufacturing technique with matrix films that had varying concentrations of nHA in the PLA. Their flammability, thermal, moisture absorption and mechanical properties were analysed in terms of the amount of nHA. The flame behavior of neat PLA and composites evaluated by the UL-94 test demonstrated that only the composite containing the highest quantity of nHA (i.e., 40 wt% nHA in matrix) was found to achieve an FH-1 rating and exhibited no recorded burn rate, whereas other composites obtained only an FH-3. The thermal degradation temperature and mass residue were also observed, via thermogravimetric analysis, to increase when increasing concentrations of nHA were added to the NF composite. The tensile strength, tensile modulus and flexural modulus of the neat resin were found to increase significantly with the introduction of flax fibre. Conversely, moisture absorption was found to increase and mechanical properties to decrease with both the presence of NF and increasing concentrations of nHA, and subsequent mechanical properties experienced an obvious reduction.

scholarly journals Effects of Rice Straw Powder (RSP) Size and Pretreatment on Properties of FDM 3D-Printed RSP/Poly(Lactic Acid) Biocomposites

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3234
Author(s):  
Wangwang Yu ◽  
Lili Dong ◽  
Wen Lei ◽  
Yuhan Zhou ◽  
Yongzhe Pu ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Rice Straw ◽  
Fused Deposition Modeling ◽  
Flexural Modulus ◽  
Tensile Modulus ◽  
Cost Effective ◽  
Poly Lactic Acid ◽  
Fused Deposition ◽  
Interfacial Compatibility ◽  
3D Printed

To develop a new kind of environment-friendly composite filament for fused deposition modeling (FDM) 3D printing, rice straw powder (RSP)/poly(lactic acid) (PLA) biocomposites were FDM-3D-printed, and the effects of the particle size and pretreatment of RSP on the properties of RSP/PLA biocomposites were investigated. The results indicated that the 120-mesh RSP/PLA biocomposites (named 120#RSP/PLA) showed better performance than RSP/PLA biocomposites prepared with other RSP sizes. Infrared results showed that pretreatment of RSP by different methods was successful, and scanning electron microscopy indicated that composites prepared after pretreatment exhibited good interfacial compatibility due to a preferable binding force between fiber and matrix. When RSP was synergistically pretreated by alkaline and ultrasound, the composite exhibited a high tensile strength, tensile modulus, flexural strength, and flexural modulus of 58.59, 568.68, 90.32, and 3218.12 MPa, respectively, reflecting an increase of 31.19%, 16.48%, 18.75%, and 25.27%, respectively, compared with unmodified 120#RSP/PLA. Pretreatment of RSP also improved the thermal stability and hydrophobic properties, while reducing the water absorption of 120#RSP/PLA. This work is believed to provide highlights of the development of cost-effective biocomposite filaments and improvement of the properties of FDM parts.

scholarly journals Improving the mechanical properties of polypropylene composites with coconut shell particles

2021 ◽  
Vol 30 ◽  
pp. 263498332110074
Author(s):  
Henry C Obasi ◽  
Uchechi C Mark ◽  
Udochukwu Mark
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Flexural Modulus ◽  
Filler Particle ◽  
Tensile Modulus ◽  
Coconut Shell ◽  
Polypropylene Composites ◽  
Increase With Increase ◽  
Pp Composites ◽  
Shell Particles

Conventional inorganic fillers are widely used as fillers for polymer-based composites. Though, their processing difficulties and cost have demanded the quest for credible alternatives of organic origin like coconut shell fillers. Dried shells of coconut were burnt, ground, and sifted to sizes of 63, 150, 300, and 425 µm. The ground coconut shell particles (CSP) were used as a filler to prepare polypropylene (PP) composites at filler contents of 0% to 40% via injection melt blending process to produce PP composite sheets. The effect of the filler particle size on the mechanical properties was investigated. The decrease in the size of filler (CSP) was found to improve the yield strength, tensile strength, tensile modulus, flexural strength, flexural modulus, and hardness of PP by 8.5 MPa, 15.75 MPa, 1.72 GPa, 7.5 MPa, 100 MPa, and 10.5 HR for 63 µm at 40%, respectively. However, the elongation at break and modulus of resilience of the PP composites were seen to increase with increase in the filler size. Scanning electron microscope analysis showed that fillers with 63 µm particle size had the best distribution and interaction with the PP matrix resulting in enhanced properties.

scholarly journals Flexural Properties of Wet-Laid Hybrid Nonwoven Recycled Carbon and Flax Fibre Composites in Poly-Lactic Acid Matrix

Aerospace ◽  
2018 ◽  
Vol 5 (4) ◽  
pp. 120 ◽  
Author(s):  
Barbara Tse ◽  
Xueli Yu ◽  
Hugh Gong ◽  
Constantinos Soutis
Keyword(s):  
Lactic Acid ◽  
Carbon Fibre ◽  
Volume Fraction ◽  
Flexural Modulus ◽  
Fibre Volume Fraction ◽  
Fibre Volume ◽  
Flax Fibre ◽  
Morphological Properties ◽  
Poly Lactic Acid ◽  
Flexural Properties

Recycling carbon fibre is crucial in the reduction of waste from the increasing use of carbon fibre reinforced composites in industry. The reclaimed fibres, however, are usually short and discontinuous as opposed to the continuous virgin carbon fibre. In this work, short recycled carbon fibres (rCF) were mixed with flax and poly-lactic acid (PLA) fibres acting as the matrix to form nonwoven mats through wet-laying. The mats were compression moulded to produce composites with different ratios of rCF and flax fibre in the PLA matrix. Their flexural behaviour was examined through three-point-bending tests, and their morphological properties were characterised with scanning electron and optical microscopes. Experimental data showed that the flexural properties increased with higher rCF content, with the maximum being a flexural modulus of approximately 14 GPa and flexural strength of 203 MPa with a fibre volume fraction of 75% rCF and 25% flax fibre. The intimate mixing of the fibres contributed to a lesser reduction of flexural properties when increasing the flax fibre content.

scholarly journals Effects of Waste Expanded Polypropylene as Recycled Matrix on the Flexural, Impact, and Heat Deflection Temperature Properties of Kenaf Fiber/Polypropylene Composites

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2578
Author(s):  
Junghoon Kim ◽  
Donghwan Cho
Keyword(s):  
Impact Strength ◽  
Natural Fiber ◽  
Flexural Modulus ◽  
Fiber Composites ◽  
Kenaf Fiber ◽  
Polypropylene Composites ◽  
Izod Impact ◽  
Pp Composites ◽  
Heat Deflection Temperature ◽  
Kenaf Fibers

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.

Mechanical properties of wood flour/poly (lactic acid) composites coupled with waterborne silane-polyacrylate copolymer emulsion

Holzforschung ◽  
2016 ◽  
Vol 70 (5) ◽  
pp. 439-447 ◽  
Author(s):  
Ru Liu ◽  
Shupin Luo ◽  
Jinzhen Cao ◽  
Yu Chen
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
High Performance ◽  
Coupling Effect ◽  
Wood Flour ◽  
Flexural Modulus ◽  
Coupling Agents ◽  
Poly Lactic Acid ◽  
Effective Coupling ◽  
Methacryloxypropyl Trimethoxysilane

Abstract Wood flour/polylactic acid (WF/PLA) composites were produced with a WF content of 50% based on three types of waterborne polyacrylate (PA) emulsions including a PA homopolymer emulsion and two types of silane-PA copolymer emulsions as coupling agents. Two silanes were in focus, namely, γ-methacryloxypropyl- trimethoxysilane (silane-1) and vinyltrimethoxysilane (silane-2). The emulsions and the modified WFs were characterized, and the effects were investigated in terms of emulsion type and their loading levels on the mechanical properties of WF/PLA composites. (1) Both types of silanes could be successfully copolymerized with PA to form stable emulsions. (2) With increasing PA loading, the mechanical properties (except for flexural modulus) of the composites increased at first before reaching the maximum values at 4% PA loading and then the properties worsened. However, these values were larger than those of pure composites, especially in cases when PA-silane emulsions were applied. (3) PA modified with silane-1 showed the best coupling effect among all the three PA emulsions. The results can be interpreted that PA emulsions are effective coupling agents for the preparation of high-performance WPCs.

Screwless Extrusion of Natural Fibre-Reinforced Thermoplastic Composites

2004 ◽  
pp. 27-32
Author(s):  
Timothy Galea ◽  
Tony Mills ◽  
Rex Halliwell ◽  
Krishnan Jayaraman
Keyword(s):  
Natural Fibre ◽  
Thermoplastic Composites

scholarly journals Acoustic Emission Applied to Failure Analysis of Commingled Yarn GF/PP Composites in Transverse Tension and Mode I Delamination

2003 ◽  
Vol 12 (5) ◽  
pp. 096369350301200 ◽  
Author(s):  
D. Lariviere ◽  
P. Krawczak ◽  
C. Tiberi ◽  
P. Lucas
Keyword(s):  
Acoustic Emission ◽  
Thermoplastic Composites ◽  
Mode I ◽  
Fibre Reinforcement ◽  
Transverse Tension ◽  
Commingled Yarn ◽  
The Matrix ◽  
Pp Composites ◽  
Loading Modes ◽  
Mode I Delamination

This work aims to analyse the influence of the fibre/matrix interface on the acoustic response of commingled yarn thermoplastic composites submitted to transverse tension and mode I fracture mechanics loading. For this purpose, different interfacial qualities were obtained by modification of the fibre reinforcement sizing and the matrix coupling. The acoustic emission rate (number of acoustic events emitted per time unit) has appeared suitable to quantify the damage involved by the mechanical loading according to the interfacial quality. The comparison of the acoustic emission obtained for the two loading modes has shown that, although the amplitude range [59-66dB] is characteristic of interfacial debondings in transverse tension, it is no more the case for a mode I delamination test for these commingled GF/PP composites.

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