Cotton Fiber-Reinforced Polypropylene Composites

2011 ◽  
Vol 138-139 ◽  
pp. 581-587 ◽  
Author(s):  
Tao Lin ◽  
Zheng Wang ◽  
Wen Jing Guo

Cotton stalk is a by-product of cotton planting process, and a great resource as a raw biomass material for manufacturing value-added composite products. The fine structure and fiber size of the cortex, xylem of the cotton stalk were studied in this paper. In addition, a new method for the processing of cotton stalk filament was developed. Composites consisting of polypropylene (PP) and cotton stalk filament were prepared by hot pressing. The effects of PP content and compressing temperature on the mechanical properties of cotton stalk filament /PP composites were studied. The results show that elevated temperatures, all of the composites are substantially stiffer and stronger than that at lower temperature. PP content improves the intensity and adhesion of composites. Simultaneous optimization of composites properties indicates that the composites with PP content of 40% and the compressing temperature of 195°C would sufficient meet the requirements of the GB/T 4897.1-2003 standard. Bio-renewable materials such as cotton stalk can be used as reinforcing materials for plastic composites.

2021 ◽  
Vol 30 ◽  
pp. 263498332110074
Author(s):  
Henry C Obasi ◽  
Uchechi C Mark ◽  
Udochukwu Mark

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.


2017 ◽  
Vol 37 (4) ◽  
pp. 401-409 ◽  
Author(s):  
Zhanyu Zhai ◽  
Christian Gröschel ◽  
Dietmar Drummer

Abstract The objective of this study was to determine the engineering constants and off-axis tensile stress-strain relation of single-ply quasi-unidirectional (UD) glass fiber (GF)/polypropylene (PP) composites using the new approach. A series of off-axis tensile tests of quasi-UD composites were carried out. In this study, Puck’s interfiber fracture criterion was expanded for the first time to estimate the off-axis tensile stresses of UD composites. With the experimental values, the shear properties were obtained through the curve-fitting methods. Damage mechanisms were demonstrated to evolve with the loading angle. By comparison to experimental data, the Hahn-Tsai equation, together with the transformation equation, was found to be adequate to describe the off-axis tensile stress-strain relation of single-ply quasi-UD GF/PP composites.


2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Shibin Nie ◽  
Chi Zhang ◽  
Chao Peng ◽  
De-yi Wang ◽  
Daowei Ding ◽  
...  

A char forming agent (CFA) and silica-gel microencapsulated ammonium polyphosphate (Si-MCAPP) were selected to form novel intumescent flame retardant system to prepare flame retardant polypropylene (PP) composites, and then the influences of nanoporous nickel phosphates (NiP) on the thermal and flame retardant properties of flame retardant PP composites were studied by the real time FTIR (RTFTIR) spectra, limited oxygen index (LOI) test, and the scanning electron microscopy. RTFTIR shows the addition of NiP can improve the thermal stability of flame retardant PP composites. LOI test shows LOI value is increased with the increase of the content of NiP, and the optimized concentration of NiP is 1.0%. Furthermore, smoke toxicity of the novel flame retardant PP composites was studied by mice experiment. The upper limit of the no death smoke concentration of the composite is 12.37 mg/L.


2019 ◽  
pp. 089270571986940
Author(s):  
Chuigen Guo ◽  
Ran Chen ◽  
Liping Li

The main aim of this study was to evaluate the thermal degradation and flame retardancy of straw flour (SF)-polypropylene (PP) composites and wood flour (WF)-PP composites. Biomass silica exists in SF, despite only 18 wt% loading of ammonium polyphosphate (APP); the APP in combination with biomass silica can effectively improve the flame retardancy on total heat release, heat release rate (HRR), mass loss rate, time to ignition (TTI), and limited oxygen index; it can obtain UL-94 V-0 rating, reduce the average and peak HRR by 44% and 41%, respectively, and increase the TTI by 8%. It attributes to the interaction effect between biomass silica in SF and APP, which more effectively enhances the thermal stability of the SF/PP/APP composites at high temperature and increases the char residue. The silica could form an intercalated network in char structure and then boost the physical integrity. The enhanced physical integrity and thermal stability lead to an effectively synergetic effect on flame retardancy of SF/PP/APP composites.


2020 ◽  
Vol 15 ◽  
pp. 155892502095819
Author(s):  
Qianting Wang ◽  
Yu Zhang ◽  
Weikang Liang ◽  
Jianjie Wang ◽  
Youxin Chen

In this work, the surface of the bamboo fibers (BF) was treated with three kinds of silane coupling agents terminated with amino functional groups (KH550), epoxy functional groups (KH560), and methyl functional groups (KH570) to improve fiber–matrix adhesion. The effects of silane treatment on the mechanical properties and thermal behavior of BF/polypropylene (PP) composites were investigated. Mechanical test results showed that the order of modification effectiveness was KH570 > KH550 > KH560. KH570 treated fiber composite exhibited the best mechanical properties. The tensile strength and flexural strength of 5 wt% KH570 treatment reached to 36.1 and 54.7 MPa, which were 15.4% and 23.6% higher than those of UBF/PP composites. Simultaneously, the thermal stability increased from 467.0°C (UBF) to 470.6°C (KH-570 treated BF). An increase in crystallization temperature (1.7°C) and a decrease in crystallinity (5.8%) occurred upon the addition of 5% KH570 silanes treated bamboo fibers.


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.


2013 ◽  
Vol 849 ◽  
pp. 269-276
Author(s):  
Olli Väntsi ◽  
Timo Kärki

The heat build-up and fire performance of wood plastic composites containing recycled mineral wool filler were investigated. Six wood polypropylene composites with recycled mineral wool content between 0 % and 64 % were evaluated. It was found that the heat build-up of the studied composites increased with initial addition of recycled mineral wool, but increasing the content of recycled mineral wool in the composites further did not have a notable effect onthe heat build-up. Fire performance investigation showed that the addition of recycled mineral wool into the composites did not decrease the magnitude of heat release rate peak, but decreased the total heat release of the composites. Investigation of residual masses after the pyrolysis demonstrated a good dispersion of recycled mineral wool fibers in the polymer matrix. It is concluded that fire protection of the polymer matrix is essential when developing the fire performance of wood plastic composites with recycled mineral wool as filler.


2018 ◽  
Vol 929 ◽  
pp. 70-77 ◽  
Author(s):  
Ismojo ◽  
Rai Pratama ◽  
Ghiska Ramahdita ◽  
Anne Zulfia Syahrial ◽  
Mochamad Chalid

Polypropylene (PP) is one of the biggest petro-polymers, which is used in very wide application nowadays. The environment problem due to materials such as plastics having very long time degradability, and critical petroleum sources have promoted some studies to empowerment of natural resources such as natural fibres for substituting or at least modifying petro-polymers. Because of biodegradability obtained from natural source, sorghum fibers are interesting to be used as filler in PP composites, despite of weak compatibility between them. Surface modification on the sorghum fibers through alkalinization prior to acetylation was aimed to improve the fiber compatibility to PP. The treatments were expected to substitute hydroxyl group in the sorghum fibers, into acetic ester group in order to increase their hydrophobicity as the fillers. Moreover, the treatments were able to unbundle single fibers into micro-fibrillated cellulose (MFC) fibres with increase in crystallinity index. Usage of this MFC fiber as filler in PP leads to improvement of the composite performances such as thermal properties. In this study, Fourier Transformation Infra-Red (FTIR) Spectroscopy, X-ray Diffraction (XRD), Differential Scanning Calorimetry (DSC) and Field-Emission Scanning Electron Microscope (FE-SEM) were used to evaluate the performances of the Sorghum fibers after the treatments and as the filler in the Sorghum fibers/PP composites. The experimental results showed the MFC fibers as the smallest sizes in 5.0 microns and the highest crystallinity index up to 79.1 %, obtained from alkalinization with 2.5 M NaOH prior to acetylation with 17.4 M CH3COOH and the glacial (CH3CO2)2. Compatibility study of the treated Sorghum fibers on PP shows an improvement indicated by a strong interaction between the fibers and PP on morphology observation, increase in melting point of PP from 163.4°C (using virgin Shorgum fibers) into 163.6°C (using treated Sorghum fibers) in DSC measurements.


Materials ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 152 ◽  
Author(s):  
Nerea Pérez ◽  
Xiao-Lin Qi ◽  
Shibin Nie ◽  
Pablo Acuña ◽  
Ming-Jun Chen ◽  
...  

Polypropylene (PP) is currently widely used in areas requiring lightweight materials because of its low density. Due to the intrinsic flammability, the application of PP is restricted in many conditions. Aluminum trihydroxide (ATH) is reported as a practical flame retardant for PP, but the addition of ATH often diminishes the lightweight advantage of PP. Therefore, in this work, glass bubbles (GB) and octacedylamine-modified zirconium phosphate (mZrP) are introduced into the PP/ATH composite in order to lower the material density and simultaneously maintain/enhance the flame retardancy. A series of PP composites have been prepared to explore the formulation which can endow the composite with balanced flame retardancy, good mechanical properties, and low density. The morphology, thermal stability, flame retardancy, and mechanical properties of the composites were characterized. The results indicated the addition of GB could reduce the density, but decreased the flame retardancy of PP composites at the same time. To overcome this defect, ATH and mZrP with synergetic effect of flame retardancy were added into the composite. The dosage of each additive was optimized for achieving a balance of flame retardancy, good mechanical properties, and density. With 47 wt % ATH, 10 wt % GB, and 3 wt % mZrP, the peak heat release rate (pHRR) and total smoke production (TSP) of the composite PP-4 were reduced by 91% and 78%, respectively. At the same time, increased impact strength was achieved compared with neat PP and the composite with ATH only. Maintaining the flame retardancy and mechanical properties, the density of composite PP-4 (1.27 g·cm−3) is lower than that with ATH only (PP-1, 1.46 g·cm−3). Through this research, we hope to provide an efficient approach to designing flame retardant polypropylene (PP) composites with low density.


2010 ◽  
Vol 33 ◽  
pp. 487-491 ◽  
Author(s):  
Xiao Lei Guo ◽  
Hui Nan Liu ◽  
Wei Gao ◽  
Ping Xiang Cao ◽  
Yong Guo

Wood plastic composites (WPCs) are the industrial products. It is made out of wood waste fibre and waste plastic glued together by heat and pressure. Nowadays WPCs products are preferred over solid wood in many applications due to certain comparative advantages. Sawing is the machining operation frequently used in manufacturing parts of WPCs. The aim of this article is to study the effect of cutting speed on surface roughness in different WPCs sawing. A plan of WPCs sawing experiments was preformed with prefixed cutting parameters. The objective was to establish correlation between rice hull flour/PE composite, rice hull flour/PP, rice hull flour/PVC and cutting speed with the surface roughness after sawing. The results show that the spindle speed had significant effects on the surface qualities of rice hull flour/PE composites, rice hull flour/PVC composites and rice hull flour/PP composites. The advantage of using a high cutting speed in WPCs sawing is evident. With appropriate cutting parameters, one can obtain surfaces with Ra<6μm and to get surfaces qualities (dimensional precision) in workpiece of different WPCs.


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