Alkali Treatment of Kenaf Fiber Mat and its Influence on the Performance of Unsaturated Polyester/Kenaf Fiber Mat Composites

2014 ◽  
Vol 1024 ◽  
pp. 171-174 ◽  
Author(s):  
Razaina Mat Taib ◽  
Dody Ariawan ◽  
Zainal Arifin Mohd Ishak

Non-woven kenaf fiber mats were prepared from untreated and alkali treated fibers by using a carding machine followed by needle punching. The alkali treatment was carried out by immersing the fiber mats in 6% NaOH solution for 0, 1, 2, 3, 4, and 5 h at room temperature. The untreated and alkali treated fiber mats were impregnated with unsaturated polyester resin via a resin transfer molding technique to form composites. Maximum improvements of flexural strength and flexural modulus of the composites were observed when the fiber mat was alkali treated for 3 h. The improved of both properties can be attributed to better fiber-matrix adhesion between the alkali treated kenaf fiber and the unsaturated polyester matrix most probably via mechanical interlocking. Water absorption tests were conducted by immersing the composite samples in distilled water at room temperature. The water absorption patterns of all the composites were found to follow Fickian behavior. The tendency of the composites to absorb water decreased when the alkali treated fiber mats were used.

2012 ◽  
Vol 626 ◽  
pp. 449-453 ◽  
Author(s):  
Razaina Mat Taib ◽  
Nurul Mujahidah Ahmad Khairuddin ◽  
Zainal Arifin Mohd Ishak

Composites of polypropylene (PP) and kenaf fiber (KF) were immersed in water at room temperature. The fiber was treated with alkaline solution. A compatibilizer, maleic anhydride-grafted polypropylene (MAPP) was added in some composite formulations. Composite with alkali treated fibers (KFA) showed similar tensile strength but lower tensile modulus than the composite with untreated fiber, KF. Addition of MAPP was crucial to improve the tensile properties and water resistance of either PP/KF or PP/KFA composites. Alkali treatment adversely affected the water absorption behavior of PP/KF composite.


2017 ◽  
Vol 882 ◽  
pp. 89-100 ◽  
Author(s):  
Omid Nabinejad ◽  
Sujan Debnath ◽  
Teh J. Ying ◽  
Willey Y.H. Liew ◽  
Ian J. Davies

The effect of alkali treatment and nanoclay addition on the mechanical properties and water absorption behavior of rice husk particle (RHP) reinforced unsaturated polyester (UP) composites was investigated. Thermogravimetric analysis (TGA) indicated that the alkali treatment removed most of the hemicellulose and impurities from the RHP with the tensile strength, tensile modulus, flexural strength and flexural modulus of the resulting composites being improved by alkali treatment. The results indicated that the 5% sodium hydroxide concentration had the optimum performance on mechanical strength and water absorption resistance. Furthermore, the influence of nanoclay addition (1, 3 and 5 wt%) on the properties of optimum alkali treated RHP-UP composites was investigated with the lowest content (1 wt%) of nanoclay showing the highest mechanical performance. However, further addition of nanoclay improved the moisture absorption resistance of the composites. Good interface bonding between the filler and matrix was observed from scanning electron micrographs for the optimum RHP alkali treated and nanoclay dispersed RHP-UP composites.


2015 ◽  
Vol 24 (4) ◽  
pp. 096369351502400
Author(s):  
C. K. Tai ◽  
R. Ahmad ◽  
H. M. Akil ◽  
M. M. Ratnam

The combined effects of alkali treatment and compression molding temperature on the flexural strength and impact resistance of woven coir fibre composites are investigated. Ten pieces of composites plates made from single-layer woven coir fibre fabricated under different process parameters were used in the study. Five pieces of the coir woven fibre were treated with 6% sodium hydroxide (NaOH) solution while another five were left untreated. The compression molding temperature were varied between room temperature (25°C), 50°C, 75°C, 100°C and 125°C. The flexural properties of the composite were evaluated using the three-point flexural test, while the impact resistance was investigated by drop weight impact tests using a specially designed indenter. The indentation radius on each test specimen was measured using a 3-D metrology system and the depth of indentation was determined from the geometry of the indenter. The results show that the maximum flexural load to failure is improved by 38.9% when the fibres were treated and the compression molding temperature is increased to 125°C. The flexural modulus generally decreased with increase in the molding temperature. The depth of indentation in the treated coir woven composites is lower than that of untreated fibre composite at all molding temperatures. The impact resistance of both untreated and treated fibre composites decreased with the increase in the compression molding temperature. Composites fabricated by molding at room temperature, 50°C and 75°C using treated fibre produced the best impact properties.


2013 ◽  
Vol 812 ◽  
pp. 258-262 ◽  
Author(s):  
Zakaria Mohd Nazarudin ◽  
Jamaluddin Mohd Ariff ◽  
Masitah Abu Kassim ◽  
Nur Shafiqah Othman ◽  
Othman Maizatulnisa ◽  
...  

The aim of this study is to determine the effect of alkali treatment on water absorption and tensile properties of non-woven kenaf polyester composite. Kenaf fiber mat was treated with 2, 4 and 6% of different sodium hydroxide (NaOH) concentration. The composite was fabricated using compression molding technique. It was found that treatment reduced the overall water uptake of composites. The 6% treated fibre composite was greater in moisture resistance as compared to untreated. The tensile strength of the composites was substantially improved after alkali treatment, and it was similar with the tensile modulus.


2015 ◽  
Vol 1123 ◽  
pp. 147-150 ◽  
Author(s):  
Harini Sosiati ◽  
Henny Pratiwi ◽  
Dwi Astuti Wijayanti ◽  
Soekrisno

Cellulose microfibrils were extracted from kenaf fiber by alkali treatments under various conditions to further characterize their properties and verify the factors which induce fiber degradation. Before treatment, the surface morphologies of the base, middle and tip of the raw fiber were observed. The tensile strength of untreated and treated fibers was measured with a universal tensile machine (UTM). Changes in surface morphologies of cellulose microfibrils were characterized by scanning electron microscopy (SEM). Fourier transform infrared (FTIR) spectroscopy was used to characterize the functional group related to cellulosic and non-cellulosic phases. Surface morphology of the middle of the fiber was denser and stronger than that of the periphery and therefore used to define an initial condition of fiber specimen. Alkali treatment in 6% NaOH at room temperature for 1 h increased the tensile strength of the microfibril; 9% NaOH at 100°C for 2 h results in a marked decrease. Damage to the fiber surface and loss of crystallinity were associated with decreased tensile strength.


2017 ◽  
Vol 24 (5) ◽  
pp. 731-738 ◽  
Author(s):  
Varun Mittal ◽  
Shishir Sinha

AbstractThe aim of this research was to study the feasibility of using wheat straw fiber with epoxy resin for developing natural fiber-polymer composites. For this purpose, the epoxy resin was reinforced with 5, 10, 15, 20, and 25 wt.% of the wheat straw fiber with the help of the hand lay-up technique. Further, in order to improve the composite characteristic, wheat straw fibers were treated with three different concentrations of alkali (1%, 3%, and 5%). The mechanical and water absorption properties of the treated fiber composites were characterized and compared with those of untreated fiber-filled epoxy composites. It was observed that the mechanical properties and water resistance were reduced with the increase in wheat straw fiber loading from 5 to 25 wt.%. Among the three levels of alkali treatment, the composite made with 3% alkali-treated fiber exhibited superior mechanical properties than the other untreated and treated fiber composites, which pointed to an efficient fiber-matrix adhesion. The scanning electron microscope was used to observe the surface features of the wheat straw fiber.


2011 ◽  
Vol 311-313 ◽  
pp. 260-271 ◽  
Author(s):  
E. Osman ◽  
A. Vakhguelt ◽  
I. Sbarski ◽  
S. Mutasher

Kenaf fibre is a natural fibre which is growing in popularity due environmental issues and its properties as filler. Unsaturated polyester was used in this investigation via add 1% MEKP concentration ratio as the catalyst. This matrix was combined with untreated kenaf fiber with various fiber sizes (1-6) mm and (10-30) mm, alkalized with 6% NaOH solution for treated kenaf fiber to form natural fiber for two different fiber lengths composites. Composites were prepared by adding various percentages of kenaf fiber in unsaturated polyester resin. A general trend was observed whereby alkalized fiber composites possessed superior flexural strength and modulus and the maximum strength and modulus was at the 20wt% weight fraction. The length of (10-30) mm gave higher tensile and flexural properties compared to (1-6) mm. The modulus of elasticity showed a regular trend of an increase with fiber weight percent until 30% for both fiber lengths and afterwards a decrease in modulus of elasticity for composites with greater fiber weight fraction. The experimental modulus of elasticity was compared with the theoretical predictions and was found to be in good agreement with Hirsch’s model while the results obtained from Cox – Krenchel underestimating the experimental data.


2012 ◽  
Vol 530 ◽  
pp. 34-39
Author(s):  
Abdalla Abdal-Hay ◽  
Do Yeon Jung ◽  
Kang Il Lee ◽  
G.T. Abdel-Jaber ◽  
Jae Kyoo Lim

The delamination and fibers pull out have been the main factors failure application of natural fibers in various engineering fields. To address these problems, particles reinforced composites are the promising candidate. The present paper investigates on vegetal particles (date palm seed particles/DPSp) and applies it as composites material reinforced unsaturated polyester (USP). The influence of alkali treatment on the surface morphology and structure of DPSp was investigated. They investigated by SEM and Energy Dispersive Spectroscopy (EDS) mapping. The water absorption results showed directly proportion with the particles loading as the relative increases were 0.645% and 7.345% for 10 wt% and 40 wt% of DPSp content, respectively. In addition, the water absorption ability of the composites showed low value comparing with many natural fibers. In addition, the fracture toughness of the composites was studied. Overall, addition of the proposed DPSp particles may be opens a new avenue to exploit the utilized natural cheap material to produce a green composite.


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