scholarly journals Effect of Alkali Treatment Using Calcium Hydroxide and the Fiber Length on the Strength of Sugarcane Bagasse Fibers-Polypropylene Composites

2015 ◽  
Vol 815 ◽  
pp. 106-110 ◽  
Author(s):  
Juliana Anggono ◽  
Suwandi Sugondo ◽  
Steven Henrico ◽  
Hariyati Purwaningsih

Milling sugarcanes to produce sugar generates by-product called bagasse. Due to the large availability and low cost, the potential of obtaining renewable and biodegradable fibers from bagasse had been explored. To produce fibers from these bagasse, the bagasse was treated in alkali solution using 14 % v/v calcium hydroxide, Ca (OH)2 at high temperature (60-70°C) for 4 hours. After treatment and washed to remove dissolved substances, the fibers were cut into 3 and 5 cm length. Some fibers were prepared in their original length. These fibers were mixed with polypropylene (PP) matrix in weight % ratios of bagasse fibers/PP 20/80, 25/75, and 30/70 and hotpressed to make composite samples. Composites produced were characterised with tensile test to evaluate their tensile properties. Scanning electron microscopy (SEM) was performed on the fiber surface as well as on the fracture area of the tensile tested samples. Tensile strength of the composite shows an increase with the increase of the fiber length and weight % ratios of bagasse fibers/PP up to 25/75 and decreases when bagasse fibers were added to 30 wt.%. The highest strength of 11,30 MPa was obtained when 5 cm fibers were used in a weight % ratio of bagasse fibers/PP at 25/75. SEM study found a greater number of fibers oriented perpendicular to the tension direction.

2018 ◽  
Vol 38 (2) ◽  
pp. 157-166 ◽  
Author(s):  
Jian Wang ◽  
Jie Dong ◽  
Jianwei Zhang ◽  
Baodong Zhu ◽  
Dongling Cui

Abstract This work aimed to study the effects of different surface treatments on the morphologies and thermo-mechanical properties of the bamboo flour/polypropylene (BF/PP) composites, which were prepared by melt blending with 15 wt% of filler load. The BF was first pretreated with 10 wt% sodium hydroxide (NaOH) solutions for 4 h, after which the pre-treated BF was modified by stearic acid and silane. The chemical structure of the treated BF fibers was characterized through Fourier transform infrared spectroscopy (FTIR), and the results showed that alkali treatment efficiently removed hemicellulose, lignin, and pectin. Moreover, stearic acid and silane were successfully introduced to the BF surface through chemical bonding. The changes in heat stability of BF investigated by thermogravimetric analysis (TGA) revealed that the presence of treatment contributes to a better thermal stability for BF fibers. In addition, the scanning electron microscopy (SEM) observation of BF/PP composites displayed not only better dispersion of treated-BF in the polypropylene (PP) matrix, but also improved fiber-matrix interfacial compatibility, especially when silane treatment was used. Accordingly, the mechanical properties improved significantly in the presence of treated-BF.


2016 ◽  
Vol 869 ◽  
pp. 233-236
Author(s):  
Carlos Alberto Lopes Fonteles ◽  
Gustavo Figueiredo Brito ◽  
José Francisco Reis Sobrinho ◽  
Tatianny Soares Alves ◽  
Renata Barbosa

This set of mechanical properties of plant fibers allows its use as a reinforcement element in polymeric matrices and composites can be used in various sectors, and thus expanding the scope of use and the aggregate value of plant fibers. In this work, the choice by the use of alkali process to make the treatment of epicarp babassu fibers was decided in view of that it provides an effective, simple and low cost implementation process and also for being the most widely used method for modifying the surface of the fiber forming polymer composites. By SEM, it was observed the removal of wax layers, the impurities on the fiber surface and tyloses. With alkali treatment, it was also possible to notice the narrowing and closing of craters due to the packaging of denser material.


2015 ◽  
Vol 1115 ◽  
pp. 283-287
Author(s):  
Ahmed N. Oumer ◽  
Idris Mat Sahat ◽  
Muhammad Ammar Nik Mu'tasim ◽  
Tedi Kurniawan

Reinforced polymer composites are replacing metals in many engineering fields due to their high strength to weight ratio, low cost, and resistance to corrosion. In this study, the tensile properties of natural-sand particle reinforced polypropylene composites obtained by means of numerical method were compared with the experimental observations. Rectangular samples were prepared by heating the natural sand and polypropylene (PP) mixture at the melting temperature of PP and cooling in a rectangular mold. During cooling, pressure was applied on the upper part of the mold to avoid voids and shrinkages on the final sample. The concentration of the sand was varied as 5%, 10%, 15%, 20%, and 30% by weight. Then the samples were tested with 3-Point Bending and Universal Tensile Testing Machines to obtain the respective values of flexural and tensile properties of the composite samples. The numerical simulation was performed by using ANSYS software. For the simulation, structured mesh was constructed with 7500 elements and 36466 nodes. The experimental results indicated that the yield stress values dropped gradually from 21.62 MPa for 5% by weight to 8.01 MPa for 30% which leads to a conclusion that the higher the percentage of the sand particle reinforcement, the lower the tensile strength of the composite would be. Moreover, both the numerical and experimental results showed a linear increase in deflection with the increments of the applied load. These results are as expected and they confirm with the theoretical behavior of a bar subjected to axial loading. Hence, this study could assist in decisions regarding the design of reinforced composite products.


2007 ◽  
Vol 29-30 ◽  
pp. 303-306 ◽  
Author(s):  
G.W. Beckermann ◽  
K.L. Pickering ◽  
N.J. Foreman

In recent years, industrial hemp fibre reinforced thermoplastic composites have attracted substantial interest as potential structural materials. These composites have been subject to intense study for use in lightweight, recyclable and low cost applications. The aim of this research was to improve and evaluate the composite tensile strength and fibre/matrix interfacial adhesion by means of fibre treatment and addition of a coupling agent. Hemp fibre was digested in a small pressure vessel with a solution of 5wt% NaOH / 2wt% Na2SO3. Single fibre tensile tests were performed on treated and untreated fibres, and it was found that the alkali treatment resulted in an increase in fibre strength and an improvement in fibre separation. Composites containing either treated or untreated fibre, polypropylene and a maleic anhydride modified polypropylene (MAPP) coupling agent were then compounded in a twin-screw extruder and injection moulded into tensile test specimens. Tensile tests revealed that significant improvements in composite strength were made by using treated fibre and MAPP. The effect of MAPP on the interface of treated hemp fibre/polypropylene composites was assessed by means of the single fibre fragmentation test, and the interfacial shear strength was determined thereafter.


2020 ◽  
Vol 8 (6) ◽  
pp. 3958-3962

Natural fibers are considered likely to be used in polymer composite materials as reinforcing agents because of their main advantages such as fine strength and rigidity, low cost, environmentally friendly, degradable and renewable material. A study was conducted to assess the impact of properties of bicomposite made from cardanol resin banana fibers. The banana fiber extracted from the banana stem was treated with alkali to enhance the interfacial linkage around fiber and cardanol resin. Biocomposite was manufactured using formaldehyde mixed with cardanol oil to form cardanol resin mixed with banana fiber using compression moulding Techniques with different process factors such as fiber weight (5%, 10%, 15%, 20%, and 25%) different fiber length (5, 10, 15, 20, and 25 in mm) and alkali treatment (varying in 1%, 3%, 5%, 7% and 9%. The developed banana fiber reinforced composite were then characterized by impact testing showing strong significance and association in DOE using 15.2% fiber weight response surface methodology with 15.3 mm fiber length and 4.7% alkaline treated. Thus we examined the effect of the above factors on impact and suggested the best combinations of factors for composite processing


2012 ◽  
Vol 584 ◽  
pp. 551-555 ◽  
Author(s):  
Shubhalakshmi Sengupta ◽  
Dipa Ray ◽  
Aniruddha Mukhopadhyay

Abstract: The fly ash (FA) particles were coated with furfuryl palmitate (FP) in different weight % like 1, 2, 3 and 5. The FP coated fly ash particles were incorporated as filler in recycled polypropylene (RPP) matrix composites by melt mixing in 1:1 weight ratio. X-ray diffraction (XRD) analysis, Dynamic Mechanical Analysis, Differential scanning calorimetry (DSC), and Thermogravimetric analysis (TGA) of the composite samples were carried out. The presence of the coupling agent FP resulted in changes in the packing order and structural properties of the composites. It also influenced the alignment of RPP molecules with better filler –matrix interaction in 2 wt % FP coated composite as ascertained from the DSC and DMA analysis. Distinct shift in the glass transition temperature was also observed in 2 wt % FP coated composite samples. However significant improvement in the thermal stability was not observed. Thus, an unconventional, renewable, low cost coupling agent FP was found to influence the structural and thermal properties of the RPP/FA composites significantly.


2014 ◽  
Vol 695 ◽  
pp. 139-142 ◽  
Author(s):  
Siti Khairunisah Ghazali ◽  
Nadia Adrus ◽  
Jamarosliza Jamaluddin

Pineapple leaf fibers (PALF) have several advantages such as low cost, eco-friendly, and high specific strength. However, the brittleness of PALF limits its application. To overcome this limitation of PALF, it is essential to synergize the advantages of PALF with elastic properties of hydrogel. In this study, PALF was coated with polyacrylamide (PAAm) hydrogel under direct UV light exposure (UVA>300nm). Prior to this coating, PALF was alkali treated to introduce more OH group on PALF fiber. The main purpose of this study was to investigate the effect of untreated/treated PALF coated PAAm hydrogel on the flexibility of the fiber using tensile measurements. From the results, treated PALF coated PAAm hydrogel showed better results in tensile properties compared to untreated PALF due to the alkali treatment which improved the interfacial adhesion between PAAm hydrogel and fiber surface. In general, this study is precursor for further development in natural fiber coating technology.


Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2636
Author(s):  
Petr Valášek ◽  
Miroslav Müller ◽  
Vladimír Šleger ◽  
Viktor Kolář ◽  
Monika Hromasová ◽  
...  

Composite materials with natural fillers have been increasingly used as an alternative to synthetically produced materials. This trend is visible from a representation of polymeric composites with natural cellulose fibers in the automotive industry of the European Union. This trend is entirely logical, owing to a preference for renewable resources. The experimental program itself follows pronounced hypotheses and focuses on a description of the mechanical properties of untreated and alkali-treated natural vegetable fibers, coconut and abaca fibers. These fibers have great potential for use in composite materials. The results and discussion sections contribute to an introduction of an individual methodology for mechanical property assessment of cellulose fibers, and allows for a clear definition of an optimal process of alkalization dependent on the content of hemicellulose and lignin in vegetable fibers. The aim of this research was to investigate the influence of alkali treatment on the surface microstructure and tensile properties of coir and abaca fibers. These fibers were immersed into a 5% solution of NaOH at laboratory temperature for a time interval of 30 min, 1 h, 2 h, 3 h, 6 h, 12 h, 24 h, and 48 h, rinsed and dried. The fiber surface microstructures before and after the alkali treatment were evaluated by SEM (scanning electron microscopy). SEM analysis showed that the alkali treatment in the NaOH solution led to a gradual connective material removal from the fiber surface. The effect of the alkali is evident from the visible changes on the surface of the fibers.


2014 ◽  
Vol 906 ◽  
pp. 167-177 ◽  
Author(s):  
Hou Lei Gan ◽  
Lei Tian ◽  
Chang Hai Yi

Abstract: The Interface of sisal fiber which was treated by using alkali, potassium permanganate, atmospheric plasma and silane reinforced polypropylene composites were investigated by single fiber pull-out testes and surface morphology were studied. The results indicated that the morphological changes observed on the sisal fiber surface were obviously evident. Untreated, permanganate and plasma treated sisal fiber reinforced PP show a stable debonding process. Silane treated sisal fiber reinforced PP show an unstable debonding process. Single fiber pull-out tests indicated that the IFSS value was in the order of FIB < FIBKMnO4 < FIBP < FIBKH-550 < FIBKH-570. As can be seen from surface morphology of pull-out fiber, a little of PP resin was adhered to the pull-out FIB, FIBKMnO4, FIBP of sisal fiber. In contrast, PP resin at the surface of pull-out fiber was flaked off and sisal fibril was drawn out from sisal fiber were observed from pull-out fibers of FIBKH-550 and FIBKH-570.


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