Effect Of Fiber Surface Treatment Research Articles

Effect of Fibre Surface Treatment on the Properties of Eco-Core Sandwich Structures

The growing ecological, social and economic awareness, high rate of depletion of petroleum resources, concepts of sustainability and new environmental regulations have stimulated the search for green materials compatible with the environment. The focus of this research is to study the effect of fibre surface treatment as far as kenaf fibre composite sandwich structure is concern. The kenaf fibre is subjected to alkali treatment. Upon completion, the treated kenaf fibre is used for fabrication of composite sandwich structure by utilizing thermoset resin which is epoxy as the matrix and galvanized steel as the face skin. The sandwich structure undergone SEM for morphological study and three point bending test to identify the bending properties. Treated kenaf fibres shows improvement after the alkali treatment compared to untreated kenaf fibre in the composite sandwich structure.Keywords: Composite sandwich structures; biodegradable; kenaf fibres ; surface treatment; morphology

Ultra-high-molecular-weight polyethylene fiber reinforced dental composites: Effect of fiber surface treatment on mechanical properties of the composites

ObjectivesPoor interfacial adhesion between the fibers and resin matrix in the ultra high molecular weight polyethylene (UHMWPE) fiber reinforced composites (FRCs) is the main drawback of the composites. This study aims to evaluate the effect of corona and silane surface treatment of the fibers on the mechanical properties of the UHMWPE FRCs. MethodsUHMWPE fibers were exposed to corona discharges for different periods of time (0s, 5s, 7s). The surface characteristics of the UHMWPE fibers were investigated by attenuated total reflectance Fourier transformed infrared spectroscopy (ATR-FTIR), atomic force microscopy (AFM), scanning electron microscopy (SEM) and nanoindentation technique. The flexural strength and flexural modulus of the FRCs made of the treated fibers were determined on 2mm×2mm×25mm specimens. The fracture toughness (the critical stress intensity factor, KIC) of the composites was also evaluated using a three-point single edge notch beam (SENB) bending technique. Statistical analysis of the data was performed with ANOVA and the Tukey's post-hoc test. The fiber-resin interface and the fracture surface were investigated using SEM. ResultsThe change in the surface mechanical properties and chemistry of the corona treated UHMWPE fibers were monitored. The fibers exposed to corona for 5s showed higher surface nanohardness. In the FRCs, the specimens reinforced with 5s corona treated silanized fibers showed higher mechanical properties (flexural modulus, flexural strength, and fracture toughness), SEM images revealed a better adhesion between the resin and fibers after 5s fiber corona treatment and silanization. SignificanceCorona and silane treatment of UHMWPE fibers provide dental FRCs with improved mechanical properties.

Mechanical and thermal degradation behavior of sisal fiber (SF) reinforced recycled polypropylene (RPP) composites

The present investigation focuses on the effect of fiber surface treatment on the mechanical, thermal and morphological properties of sisal fiber (SF) reinforced recycled polypropylene (RPP) composites. The surface of sisal fiber was modified using different chemicals such as silane, glycidyl methacrylate (GMA) and O-hydroxybenzene diazonium chloride (OBDC) to improve the compatibility between fiber surface and polymer matrix. The experimental results revealed an improvement in the tensile strength to 11 %, 20 % and 31.36 % and impact strength to 78.72 %, 77 % and 81 % for silane, GMA and OBDC treated sisal fiber reinforced recycled polypropylene (RPP/SF) composites respectively as compared to RPP. The thermo gravimetric analysis (TGA), Differential scanning calorimeter (DSC) and heat deflection temperature (HDT) results revealed improved thermal stability as compared with RPP. The morphological analysis through scanning electron micrograph (SEM) supports improves surface interaction between fiber surface and polymer matrix.

Bio-composites: Development and mechanical characterization of banana/sisal fibre reinforced poly lactic acid (PLA) hybrid composites

The work focuses on the influencing effect of fiber surface treatment by BP towards mechanical properties of BSF reinforced PLA composites. BSF were treated by BP to improve the adhesion between fibres and matrix. BSF (30 wt %) reinforced PLA (70 wt %) hybrid composites were fabricated by means of twin screw extrusion followed by injection molding process. Tensile strength, flexural strength and modulus were tested by means of UTM. The morphological analysis of the untreated and treated BSF reinforced PLA composites in comparison with virgin PLA was carried out by SEM to examine the existence of interfacial adhesion between BSF and PLA. The resultant data reveals that treated BSF restricts the motion of the PLA matrix due to better wettability and bonding. Consequently, mechanical properties like tensile and flexural moduli of BSF reinforced PLA composites were enhanced in comparison to virgin PLA and untreated BSF reinforced PLA composites. The results are discussed in detail.

Effect of Fiber Surface Treatment on Mechanical Properties of Polylactic Acid/Empty Fruit Bunch Fiber Biocomposites

Renewable resourced green biocomposites are currently receiving much attention due to their environmental advantages. Therefore, the aim of this research is study the effect of fiber surface treatment on the mechanical properties of polylactic acid (PLA) biocomposite in order to produce a green biocomposite. Experiments were conducted by surface treatment of empty fruit bunch fiber using two methods, sodium hydroxide and silane. Both treated and untreated fibers were then melt compounded with PLA and mechanical properties of the biocomposite was studied. The results showed that silane treatment improved the reinforced biocomposite mechanical properties such as tensile strength by 33% and flexural modulus by 44% compared with untreated fiber reinforced biocomposites. This is due to the silane functional groups that act as a bridge between the PLA and fiber.

Effect of Surface Treatment on the Properties of Pineapple Leaf Fibers Reinforced Polyamide 6 Composites

In order to improve compatibility and composite properties of pineapple leaf fibers/polyamide 6 composite, alkaline and silane treatments were conducted for fiber modification. Effect of fiber surface treatment on the properties of the composites was investigated. Untreated and treated fibers were raw (R-PALF), alkaline treated (Na-PALF) and silane treated pineapple leaf fibers (Si-PALF). Fiber loading was varied in polyamide 6 based composite. Morphology and fiber-matrix interfacial adhesion, thermal and mechanical properties were examined. Surface treatments can improve interfacial adhesion between these two phases. All PALFs have enhanced thermal stability of all composites. However, thermal characteristics of the composites, i.e. Tc, Tm and crystallinity, have not been affected by PALF types. Na-PALF and Si-PALF help improving mechanical properties of the composites. Young's modulus and tensile strength have been increased whereas elongation decreased by both treated PALFs which indicates that the composites become stiffer and stronger but less flexible. From the results, it could be stated that alkali treatment is sufficient to improve compatibility and properties of the PALF/polyamide 6 composites at fiber loading of 30%wt.

Effect of fiber surface treatments on the essential work of fracture of HDPE-continuous henequen fiber-reinforced composites

Lignocellulosic fibers, such as henequen, sisal, coconut fiber (coir), jute, palm and bamboo, have been used as reinforcement materials for different thermosetting and thermoplastic resins because of their attractive physical and mechanical properties. Unlike the traditional engineering fibers, e.g. glass and carbon fibers, and mineral fillers, these lignocellulosic fibers are able to impart certain benefits such as low density, less machine wear, no health hazards, and a high degree of flexibility to the composite. The last attribute is especially true because these lignocellulosic fibers will bend rather than fracture, like glass fibers do, during processing of the composite. The mechanical properties and fracture behavior of a natural fiber reinforced polymer composite depend, not only on the properties of constituents, but also on the properties of the region surrounding the fiber, known as the interphase, where the stress transfer takes place. Moreover, the tailoring of the interphase by means of surface treatments, and carefully characterizing it, gives a better understanding of the performance of natural-fiber reinforced composites. The fracture toughness resulting from the use of natural fibers as reinforcing materials is quite different between ductile and brittle polymers, as well as between quasi-static and impact loading rates. The aim of this paper is to study the effect of the interphase properties, resulting from well controlled surface treatment of the natural fibers, on the behavior of a ductile polymer matrix composite under quasi-static loading using the essential work of fracture criteria. Specifically, the contribution of each of the different fiber-matrix interfacial adhesion levels towards the dissipation energy were analyzed and discussed. In the case of the plastic work βwp, there seems to be a synergy between the frictional and chemical interactions observed for both, low and high strain rates. The nonlinear mechanical behavior of the natural fiber under combined tensile-shear loads has also an effect on the fracture behavior of the composite. Additionally, different fiber surface treatments change the microstructural nature of the natural fiber, further affecting its behavior, particularly under high loading rates.

Effect of Fiber Surface Treatments on Thermo-Mechanical Behavior of Poly(Lactic Acid)/Phormium Tenax Composites

In the present study, Phormium Tenax fiber reinforced PLA composites were processed by injection molding and twin screw compounding with a fiber content ranging from 10 to 30 wt%. Three surface treatment methods have been used to improve the Phormium Tenax fiber-matrix interfacial bonding that are as follows: (1) aqueous alkaline solution, (2) silane coupling agent, and (3) a combination of alkaline and silane treatment. The mechanical, thermal and morphological properties of the resulting composites were investigated. The results have shown that the moduli of surface treated fiber reinforced composites are lower than the ones obtained for untreated composites (as a consequence of the decrease in fiber modulus caused by the chemical treatments) and no significant increase in strength was observed for any of the composites compared to neat PLA. SEM micrographs of composite fractured surfaces confirmed an improvement in the interfacial strength, which was insufficient nonetheless to significantly enhance the mechanical behavior of the resulting composites. Results from thermogravimetric analysis and differential scanning calorimetry suggest that surface treatment of Phormium affects the ability of PLA to cold crystallize, and the thermal stability of the composites at the different fiber contents was reduced with introduction of alkali and silane treated Phormium fibers.

Polyethylene green composites reinforced with cellulose fibers (coir and palm fibers): effect of fiber surface treatment and fiber content

Coir and palm fibers from agricultural waste were investigated as reinforcement for low density polyethylene (LDPE). The effect of fiber preparation with alkaline treatment and with/without bleaching on fiber physical properties was also an objective of this study. The chemical composition and FTIR (Fourier transform infrared spectroscopy) results confirmed that palm fibers had less impurity than coir fibers. This could be the reason for a greater fiber-matrix interfacial interaction of the palm fibers as compared to that of coir fibers, which was in good agreement with the estimation of surface free energy of the dispersion component. Moreover, fiber bleaching improved the single fiber pullout stress. Composites with both alkaline treated and bleached fibers, at different fiber contents (5, 10, 15, and 20 wt.%), were manufactured using a compression molding machine. Addition of both fibers in the LDPE matrix resulted in composites with a higher Young’s modulus compared to that of homopolymer. The Young’s modulus of the composites increased with the effect of either fiber content or fiber bleaching. Differential scanning calorimetry (DSC) showed that composites reinforced with both types of fibers had a single melting temperature peak, indicating the existence of only one type of crystalline species. Moreover, there were no significant differences in the melting temperatures for the fiber reinforced composites and the homo-LDPE. The heat of fusion decreased in the case of fiber reinforced composites.

Mechanical Properties and Water Absorption of Hemp Fibers–Reinforced Unsaturated Polyester Composites: Effect of Fiber Surface Treatment with a Heterofunctional Monomer

Hemp fibers–reinforced unsaturated polyester (UP) composites were prepared by hand lay-out compression molding. Hemp fibers were treated with isocyanatoethyl methacrylate (IEM), using dibutyltin dilaurate as a catalyst. The results indicated that fiber treatment significantly increased tensile strength, flexural strength, flexural modulus, and water resistance of the resulting composites, and yet decreased the impact strength of the composites. The water absorption characteristics for composite samples immersed in water at room temperature followed Fickian behaviour, but for those evaluated at temperature 100 °C, there was a deviation from Fickian behaviour. Scanning electron microscope graphs of the tensile-fractured surface of hemp–UP composites revealed that fiber treatment with IEM greatly improved the interfacial adhesion between hemp fibers and UP resins. Fourier transform infrared analysis of the treated fibers showed that some IEM was covalently bonded onto hemp fibers.

Sisal fiber (SF) reinforced recycled polypropylene (RPP) composites

The article focuses on the effect of fiber surface treatment on the properties and performance of sisal fiber (SF) reinforced recycled polypropylene (RPP) composites. Sisal fiber was functionalized using different surface modification methods using silane (Si), glycidyl methacrylate (GMA) and o-hydroxybenzene diazonium chloride (OBDC) in order to improve the compatibility with matrix polymer. The experimental results revealed an improvement in the tensile strength to the tune of 11 %, 20 % and 31.36 % and impact strength to 78.72 %, 77 % and 81 % for silane, GMA and OBDC treated SF reinforced RPP composites, respectively as compared to RPP. Thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and heat deflection temperature (HDT) studies revealed enhanced thermal stability of RPP after SF reinforcement. The flammability behavior of surface modified SF/RPP composites were also investigated using horizontal burning method. Improved surface interaction between fiber and polymer matrix was confirmed from scanning electron micrographs (SEM).

Effect of fiber surface treatments on the properties of short sisal fiber/poly(lactic acid) biocomposites

AbstractSisal fiber (SF)‐reinforced poly(lactic acid) (PLA) biocomposites were prepared from biodegradable PLA and surface‐untreated or ‐treated short SF by melt mixing and subsequent compression molding. It is found that the surface treatments facilitate good adhesion between SFs and PLA matrix, which is consistent with the higher mechanical properties of the treated‐SF/PLA biocomposites. Moreover, the surface treatments have similar effects on the biodegradability and water absorption of the biocomposites with the order as following: neat PLA < acetylated SF (A‐SF)/PLA biocomposite ≈ silane‐treated SF (S‐SF)/PLA biocomposite < permanganate‐treated SF (P‐SF)/PLA biocomposite < mercerized SF (M‐SF)/PLA biocomposite < untreated fiber (U‐SF)/PLA biocomposite. In terms of overall consideration of the properties, acetylation treatment seems to be the most desirable surface method owing to the maximum tensile strength and water resistance, medium impact strength, and minimum degradability of the A‐SF/PLA biocomposite. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers

Sisal fiber polymer mortar composites: Introductory fracture mechanics approach

Elevated environmental awareness and an increasing concern with the global warming have stimulated the construction, automotive, and packing industries to look for materials that can replace conventional synthetic fibers. Natural fibers appears as a good alternative since they are available in fibrous form and can be extracted from plant leaves, stalk, fruits and seeds at very low costs. In this study, the effect of fiber surface treatment on fracture properties were studied for natural sisal fiber reinforced polymer mortars (PMs). Fiber surface treatments were performed by soaking the sisal fibers in different% of NaOH and in acetic acid. Epoxy and unsaturated polyester resin were used as matrix for preparing the composites. For comparison, unreinforced and untreated sisal fiber reinforced polymer mortars were also studied. From the results it was observed that untreated sisal fiber reinforced polymer mortars have higher fracture properties than other composites. 10% NaOH sisal fiber polymer mortars show lower properties.

Effect of fiber surface treatment of poultry feather fibers on the properties of their polymer matrix composites

AbstractThis study develops the enabling technology needed to transform the fibers of poultry feather (FPF), a waste product left over after processing poultry in the food processing industry, as reinforcement filler material for manufacturing composite materials. We successfully fabricated composite materials from biopolymers (polylactide, PLA) and FPF that were produced by the extruder system. FPF‐reinforced polypropylene (PP) composites were also compounded and molded and compared to PLA/FPF composite. The composites were evaluated via thermal and mechanical analysis. To enhance the adhesion between the polymer matrix and the FPF, the FPF have been treated with sodium hydroxide, 10% maleinized polybutadiene rubber, and a silane‐coupling agent. X‐ray photoelectron spectroscopy was used to analyze the influence of modifications on the properties of fibers and found that the coupling agent was localized at the surface of the fibers. Thermal behavior of pretreated fibers was also studied by thermogravimetric analysis. All treatments clearly enhanced thermal performance of fibers. This enhancement of fiber properties, along with an improvement in fiber/matrix adhesion, led to improvement in the mechanical properties of the composite materials. It was found that the surface‐treated fiber‐reinforced materials offered superior mechanical properties compared to untreated fiber‐reinforced composite materials. Moreover, morphological studies by the scanning electron microscopy demonstrated that better adhesion between the fiber and the matrix was achieved especially for the surface‐treated fiber‐reinforced composite materials. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Effect of fiber surface treatments on mechanical and abrasive wear performance of polylactide/jute composites

The main focus of this work is to improve the adhesion of jute fiber with polylactide (PLA). For this purpose, surface of the jute fiber was modified by alkali, permanganate, peroxide and silane treatments. The surface modified fibers were characterized by FTIR spectroscopy. Unidirectional composites were prepared with treated jute fibers and PLA matrix by hot pressing of solvent impregnated prepregs. Surface treatments resulted in enhancement of tensile and flexural properties and reduction in Izod impact strength. Dynamic mechanical analysis (DMA) results showed that, treated composites have higher storage modulus and lower tangent delta with respect to untreated composite. The degree of interfacial adhesion between the jute fiber and PLA was estimated using adhesion parameter obtained through DMA data. The results of thermogravimetric analysis (TGA) showed a higher thermal stability for silane treated composites. Experimental results on abrasive wear tests revealed that the wear resistance of composite is sensitive to fiber/matrix adhesion.

Mechanical properties of surface‐treated banana fiber/polylactic acid biocomposites: A comparative study of theoretical and experimental values

AbstractCurrent study evaluates the effect of fiber surface treatments on the mechanical properties of banana fiber (BF) reinforced polylactic acid (PLA) biocomposites. Experimental results indicate increase in tensile modulus and strength upon surface treatments of BF with various silanes (APS and Si69) and NaOH. Approximately, an increase of 136% in tensile strength and 49% in impact strength was obtained in case of biocomposites with Si69‐treated BF compared with the untreated BF biocomposites. Also, experimentally determined mechanical modulus of untreated and surface‐treated BF biocomposite has been compared with the mechanical modulus calculated using various micromechanical models. Models such as Hirsch's, modified Bawyer and Bader's, and Brodnyan model showed good agreement with the experimentally determined results. Similarly, other models like Halpin‐Tsai, Nielson modified Halpin‐Tsai, and Cox's model also have been tried for the comparative study with the experimental data. Surface modification of BF showed increased interfacial adhesion between the fiber and the matrix which was evident from lowered difference between the experimentally and theoretically derived mechanical modulus. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Effect of Chemical Treatment on Mechanical and Water-Sorption Properties Coconut Fiber-Unsaturated Polyester from Recycled PET

Coconut fibers were used as reinforcement for unsaturated polyester resin from recycled PET that has been prepared using glycolysis and polyesterification reaction. Various concentrations of alkali, silane, and silane on alkalized fiber were applied and the optimum concentration of treatments was determined. Morphological and mechanical properties of the composite have also been investigated to study the effect of fiber surface treatment. The influence of water uptake on the sorption characteristics of composites was studied via immersion in distilled water at room temperature. Surface treatment of coconut fiber caused a significant increase in the tensile properties with the optimum treatment of 0.5% silane on the 5% alkalized coconut fiber/polyester composites. For water absorption study, it was observed that the treated fiber composites showed lower water absorption properties in comparison to those of untreated fiber composites. SEM investigation showed that the surface modification of fiber has better fiber-matrix interaction. Thus, chemical treatments on the fiber improve fiber/matrix adhesion especially for silane on alkalized fiber treatment.

Effects of Fiber Surface Treatment on Mechanical and Thermal Properties of Coir-MCC/Polylactic Acid Composites

Biodegradable plastic reinforced natural fiber composites are finding applications in many fields ranging from construction industry to food industry. The use of natural bio based fillers as reinforcements in composites has several advantages over inorganic fillers including lower density, renewability, and biodegradability. In this research, polylactic acid (PLA)/ microcrystalline cellulose (MCC) composites were investigated as a means to reduce the material cost and enhance the material properties. The coir fibers were used to prepare microcrystalline. Subsequently, the prepared MCC was treated with 3-amiopropyl triethoxysilane (APS) to improve interfacial adhesion between fiber and polymer matrix. Treated and untreated MCC were then mixed at 0-10 wt.% with PLA by twin-screw extruder and fabricated into test specimens by compression molding. The effects of MCC loading and surface treatment on morphology, mechanical properties, and thermal properties of PLA/MCC composites were investigated. The results showed that the PLA with 5 wt.% of MCC exhibited the best mechanical properties compared with all prepared composites. Thermal stability of PLA composites were decreased with increasing MCC content but it can be improved by treated the MCC with APS.

The Effects of Fiber Architecture and Fiber Surface Treatment on Physical Properties of Woven Sisal Fiber/Epoxy Composites

The aim of this work was to investigate the effects of fiber architecture and fiber surface treatment on flexural and impact properties of woven sisal fiber/epoxy composites. The woven sisal fibers with three different weave types including plain weave (P-weave), harness satin weave (S-weave) and right hand twill weave (R-weave) were used. For untreated fiber/epoxy composites, the fiber contents in the composite were 0, 5, 10 and 15% by weight (%wt). The untreated S-weave sisal fiber/epoxy composites showed the best overall properties and the composites with 15% fiber loading showed the highest properties. When compared to pure epoxy, flexural strength, flexural modulus and impact strength of the composite with 15% wt fiber increased by 4.5%, 60.6% and 150% respectively. Therefore, the composite of 15% wt silane treated S-weave and epoxy was prepared in order to study the effect of fiber surface treatment. The results showed that the composite containing 15% wt silane treated fiber possessed nearly the same properties with the untreated fiber/epoxy composite.

Effect of Fiber Surface Treatment on Interfacial Mechano-Electric Properties of Carbon Fiber Reinforced Concrete

The effect of carbon fiber surface treatment on interfacial mechano-electric properties of carbon fiber reinforced concrete is studied by single fiber pull-out testing. As-received carbon fiber is with poor surface polarity, and the fiber-matrix interface bonding strength is low. Surface treatment of the carbon fiber improves both the interfacial bonding strength and the interfacial ductility. The interfacial bonding force and interfacial resistance increased linearly with increasing displacement until the fiber-matrix debonding was completed. The superior interfacial mechanical properties can help improve the strain-sensing ability relates to the better repeatability and reliability. But the sensitivity decreases to some extent.