1. Introduction

Glass fibers are the most common of all reinforcingfibers for polymeric matrix composites. The GFRPcomposites always consist good strength to weight ratiothan metal matrix. In GFRP fibers and matrix retain theirphysical and chemical identities to provide goodcombined properties. The uses of light weight materialsincrease the fuel efficiency of automobile and airplanes.The properties were improved by addition of inorganicexfoliated minerals of some weight percentage in thepolymer matrix composites [1-2].The properties of composites were improved

significantly owing to higher bond strength [3]. Theresults were analyzed that sharp enhancements inmechanical properties can be achieved by the addition ofparticulate in chemical compound matrices [4]. Thestructural properties were improved with increase inparticulate loading [5]. Small volume of filler additionexposed drastic improvement of modulus of composites.The addition of aluminum oxide Al2O3 nano particles

with epoxy matrix leads the improved impact toughnessto little volume share [6]. Various particulate stuffedhybrid composites were experimentally studied and theirimproved characteristics of hybrid woven jute and glassfiber composites were familiar [7]. CaCO3 particle wasstuffed with the composites and measured toughness was

experimentally analyzed. The linear improvement wasshown from the results [8].

Improvement of chemical resistance of thecomposites is suitable for fuel tanks and launch vehicles[9]. The influence of particles provides additionalresistance to fracture [10]. The changes in mechanicalproperties were studied in CaCO3 reinforcement fibercomposites [11]. In this paper, the fiber reinforcedcomposites were made with TiO2 particulate fillermaterial and without particulate filler material in theunsaturated polyester resin. The light metal oxide powdertitanium oxide was used as filler material because theweight of the powder is comparatively less than othermetals and the bonding strength of the oxide powder isgood in the resin matrix. The polymer composites weresubject to various experiments to determine tensile,impact strength, hardness, chemical and thermalproperties.

2. Experimental details

2.1 MaterialsThe hybrid composites were made with at random

familiarized short e-glass fiber with 10 mm length,unsaturated polyester resin and particulate material (TiO2).Physical properties of titanium oxide are given in table 1.E-glass fibers having density of 2.5 g/cm3, Elongation of2.5% and modulus of 70 GPa were used as a reinforcingmaterial in matrix.

Preparation and Characterization of Glass Fiber Reinforced Composite with TiO2Particulate

S. Srinivasa Moorthy＊1, # and K. Manonmani＊2

＊1Faculty of Production Engineering, Government College of Technology, Coimbator-641 013,Tamilnadu, India

＊2Faculty of Mechanical Engineering, Government College of Technology, Coimbator-641 013,Tamilnadu, India

# corresponding author

Abstract : Glass fiber reinforced polymer (GFRP) composites are widely employed in aerospace and automotiveindustries because of light weight, wear resistance with lower price. To have the better characteristics of GFRPcomposites, titanium oxide light metal filler was added in the unsaturated polyester resin matrix. The hybrid GFRPcomposites were made with 10 wt % of filler content and without the filler material. The integration of added fillermaterial reinforcement and increased fiber content are compared and gives improved tensile, impact and hardness fromthe series of experiments. Chemical resistance and thermal property of GFRP composites were increased due to thehybrid reinforcement.

(Received 5 April, 2013 ; Accepted 2 July, 2013)

Transaction

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Fiber and organic compound were procured fromsmall Industries Development Corporation (SITCO),Coimbatore, Tamilnadu, India. Methyl ethyl ketone wasan accelerator and cobalt (ii) naphthenate was used ascatalyst. Pale yellow colour liquid polyester resin wasused as matrix. Unsaturated polyester resin is animportant thermoset resins used in various applicationsdue to its ease of molding characteristics, handling, andcured properties [12].2.2 Specimen PreparationThe mould was initially kept cleaned and a release

agent wax polish was laid up on the mould. The resin wasmixed with the accelerator and catalyst of 1.5 wt%respectively. The particulate material was mixed andstirred well. The resin mixture was laid up on the mould.The fiber content of the composites was made bydifferent (10 wt %, 20 wt %, 30 wt %, 40 wt %, and 50 wt%) compositions and the particulate content was kept at10 wt% constant. The designations of various compositesproduced are shown in Table 2. The mould was closedand pressed uniformly for 24 hours at room temperaturefor curing. After curing the composites were cut to thestandard sizes. The specimen preparations of thecomposites are given in figure 1.

2.3 Mechanical CharacterizationTensile test was conducted on a computerized UTM-

TIRA with 50 mm/min of cross head speed according tothe guidelines of ASTM D638. The impact test wascarried out on International equipments impact testingmachine with ASTM D256. Hardness of GFRP compositematerials was measured using Rockwell hardness tester.Three samples for every test were carried out at roomtemperature. 2N of concentrated H2SO4and HCl was usedto perform the chemical resistance analysis. The thermalstability of the composites was measured with a thermalgravimetric analyzer. The samples were heated fromambient temperature to 600°C under dry nitrogen at aheating rate of 10 °C/min.

3. Results and discussion

3.1 Tensile StrengthThe tensile strength of the composite was increased

with increase in fiber content with particulate loading upto 40 wt% of fiber content and after decreased. Thevalues of peak load obtained during tensile strength withparticulate and without particulate are shown in Table 3.The tensile strength was improved due to the fibers act ashard inclusions in the matrix due to the unsaturatedpolyester resin provided the double bonding matrix. Alsothe titanium oxide filler may act as the secondaryreinforcement to improve the tensile strength.Tensile strength of the composite materials having

Table 1 Physical properties of titanium oxide

Table 3 Tensile strength values for 10 mm fiber loadingwith particulate and without particulate.

Fig. 1 Specimen preparation.

Table 2 Composites with different wt% of fiber contentcompositions.

Fig. 2 Effect of fiber and particulate loading on thetensile force.

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fiber with particulate and without particulate is shown infigure 2. The result showed that the tensile strengthgradually increased due to increase in weight% of fiberand particulate loading.The improved tensile strength was ensured that, the

particulate was made good bond with the matrix. Figure 3and 4 shows the micro structure image of the TiO2particulate filled GFRP composites.

The composite having fiber length of 10 mm, thetensile strength increases up to 40% of weight and thendecreased. It may be the maximum content of fibercaused the weak bond in the matrix at 50 wt% due to lesscontent of the resin. The tensile test results showed thatthe hybrid composite made using fiber with particulateobtained the maximum value of 0.133 GPa.3.2 Impact strengthThe pendulum axe swinging at a notched sample of

material with dynamic loading was obtained. The impactstrength for the specimens is given in Table 4. It showsthat impact strength of GFRP composites improved withincrease in fiber loading and particulate content.The impact test results showed that the fiber content

with particulate having 50wt% of with particulate andwithout particulate possess the highest of 5.4×103 J/m and7.1×103 J/m. Because e-glass fiber and TiO2 dual

reinforcement composite has a much higher fractureinitiation energy than other composites owing to itshigher strain energy absorption capacity. The secondaryreinforcement TiO2 with the e-glass fiber may arrest theadvancing of the crack and reduce the severity of the loadapplied. The maximum of 31.11% improvement wasobtained in the composites with particulate material.Percentage of improvement = [Maximum impact

strength with particulate − Maximum impact strengthwithout particulate] / Maximum impact strength withparticulate.

3.3 HardnessThe Rockwell hardness scale was supported the

indentation on hybrid composite materials. The Rockwelltest determines the hardness by measure the depth ofpenetration of an indenter underneath a large loadcompared to the penetration created by a preload. Theindenter used was the 3.175 mm steel ball. The hardnessof the GFRP composites depends on the matrix, fiberloading and filler content. The hardness was measure withfiller material and without filler material was done onRockwell hardness tester. The Rockwell hardness number(RNH) of those composites is shown in figure 5.The Rockwell hardness values were enlarged with

increase in fiber loading and filler material. Themaximum values of RNH with particulate and withoutparticulate are 67 and 60 respectively. The hardness wasimproved 21% due the hybrid reinforcement.

Table 4 Percentage of improvement of impact strengthwith particulate and without particulate.

Fig. 3 & 4 Microstructure image of the TiO2 filledGFRP composites.

Fig. 5 Rockwell hardness of composite withparticulates and without particulates.

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3.4 Chemical resistance AnalysisThe Chemical resistance analysis (CRA) was meted

out by weight loss/gain methodology. The values ofweight loss/gain of different composites with particulateand without particulate was examined and recordedduring the chemical tests with H2SO4 and HCl. The loss inweight of different composites with 2N concentrated HClas per designations is given in tables 5 and 6. The resultreveals the particulate composite has additional chemicalresistance with HCl.

The CRA was also conducted with 2N ofconcentrated H2SO4 by weight loss methodology. Theweights of the composites were measured before and afterthe reaction with H2SO4. Different values obtained withthis analysis are given in Table 7 and Table 8.The results from CRA showed that the resistance to

chemicals of GFRP composites improved with increase infiber and particulate loading. When the chemical reactiontakes place in the GFRP composites, there may be achange in the chemical structure of the compositescausing a change in molecular weight. Hence, there was achange in weight of 30 wt% fiber content composite. Thecharacterization of the composites reveals that thechemical resistance was increased with the increase in theparticulate loading in the composite specimens. Thereinforcement characterization with all these properties, it

will be implemented in the applications of automotiveengine parts.3.5 Thermal AnalysisThermal stability of the composites was measured

with Gravimetric analyzer. The weight loss of thecomposites was obtained with various temperature ranges.The weight of the composites was gradually reduced withthe temperature range. Table 9 shows the weight loss ofvarious designations of the composites.

Table 7 Chemical test of the fiber composite withoutparticulate in H2SO4.

Table 5 Chemical Test of the Fiber Composite withoutParticulate in HCl.

Table 8 Chemical test of the fiber composite withparticulate in H2SO4.

Table 6 Chemical test of the fiber composite withparticulate in HCl.

Table 9 Weight loss of hybrid composites in thermalanalysis.

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4. Conclusion

The development and characterization of a new setof fabrication of hybrid GFRP composites were meted out.The composites were characterized with relevancy oftheir mechanical, chemical and thermal characteristics.Mechanical experiments, chemical resistant analysis andthermal analysis were meted out to study the result ofvariable fiber content (10 wt%, 20 wt%, 30 wt%, 40 wt%and 50 wt %) and constant particulate content on thecomposite strength. The maximum tensile strength (0.133GPa) was obtained. The impact strength and hardnesswere multiplied and 7.1x103 J/m of maximum impactstrength and 67 RNH were obtained. The weight of thecomposites samples were analyzed before and after thecheck with 2N of concentrated HCl and H2SO4. Theparticulate hybrid composite had more chemicalresistance within the comparative study. Thermal test ofthe composites was analyzed and ensured the TiO2particulate stuffed composites had more thermal stability.

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