Homogeneous Distribution Of Filler Research Articles

Naphthalene Tetrazole-Based Nickel Metal-Organic Framework as a Filler of Polycarbonate Membranes to Improve CO2 and H2 Separation.

A tetrazole-naphthalene linker was used to prepare a nickel MOF (metal-organic framework) (NiNDTz) with interesting properties: a specific surface area SBET of 320 m2g-1 (SLangmuir 436 m2g-1), high thermal stability (Tdonset = 300 °C), and CO2 uptake of 1.85 mmolg-1, attributed to the tetrazole groups to be used as fillers in gas separation membranes. The role of these groups was crucial in the mechanical properties of mixed membranes prepared using polycarbonate as a polymer matrix, providing a very homogeneous filler distribution and also in the gas separation properties since a simultaneous increase in permeability and selectivity was achieved, especially in the hybrid membrane containing 20% filler (PC@NiNDTz-20%). This membrane exhibited an excellent balance between permeability (P) and selectivity (α) with an increase in the permeability of CO2 and H2, 177 and 185%, respectively, and improvements in the selectivity of these gases against greenhouse gases such as methane and ethylene (between 15 and 28% improvement). These results make this membrane competitive to deal with separations in which these gases are involved, and are of special interest for the H2/CH4 separation since it clearly improves the performance of pure PC and no better PC-based membranes have been reported in the literature for this separation.

Sustainable, Alternative Conductive Fillers for Flexible Electronics: Investigation of Filler Size on Morphological and Electrical Properties of Styrene-[Ethylene-(Ethylene-Propylene)]-Styrene Block Copolymer (SEEPS) Composites

Sustainability is getting popular for many engineering applications from packaging to textiles, energy to electronics. Since renewable, environmental friendly sources lowers the negative impacts of the end product on ecology, sustainability studies generally start with the raw materials. The sustainability of electronic materials has gained importance because of limited amount of resources and increasing costs as well as environmental restrictions. In this study, pistachio shell waste was used to synthesize conductive fillers for the fabrication of sustainable flexible electronics. Pistachio shell waste was carbonized. After carbonization, two different grounding settings were used to obtain different filler sizes. In order to compare the effects of filler size on electrical and morphological properties of the composites, six different samples were prepared based on filler concentration with styrene-[ethylene-(ethylene-propylene)]-styrene block copolymer. Homogeneous filler distribution and good filler-matrix interface were observed for both composite sets. Filler size was found significant in terms of the electrical conductivity of the composites. For larger fillers, the percolation region was found to shift to lower concentration compared to smaller filler size.

Improved dielectric and mechanical properties of Ti3C2Tx MXene/silicone rubber composites achieved by adding a few boron nitride nanoplates

MXenes have attracted great attentions in the fabrication of dielectric polymer composites because of their excellent electrical conductivity. However, the high dielectric loss tangent would suppress the application of such polymer-based composites. Incorporating insulating fillers might be a solution. Herein, Ti3C2Tx MXene/silicone rubber (SR) composites incorporated with boron nitride (BN) nanoplates were prepared. The homogeneous distribution of fillers was obtained in the composites, which was also thermally stable up to 400 °C. Dielectric constant of 7.06 (2.54 times of pure SR) and dielectric loss tangent of 0.00131 were achieved when the filling contents of MXene and BN in SR composite were 1.2 wt% and 5 wt%, respectively. The improved dielectric constant can be ascribed to the enhanced interfacial polarization and the formation of conductive network, while the low dielectric loss tangent can be due to the insulating interlayers of BN which could inhibit the transfer of free electrons from conductive fillers to the insulating polymer matrices. BN/MXene/SR composites displayed improved mechanical properties (tensile stress of 671 kPa and elongation at break of 353%) and good flexibility (elastic modulus of 540 kPa) due to the low filling content of fillers. This work is promising for preparing dielectric polymer composites in applications of electronic devices.

Cellulose Triacetate-Based Mixed-Matrix Membranes with MXene 2D Filler-CO2/CH4 Separation Performance and Comparison with TiO2-Based 1D and 0D Fillers.

Mixed-matrix membranes (MMMs) possess the unique properties and inherent characteristics of their component polymer and inorganic fillers, or other possible types of additives. However, the successful fabrication of compact and defect-free MMMs with a homogeneous filler distribution poses a major challenge, due to poor filler/polymer compatibility. In this study, we use two-dimensional multi-layered Ti3C2Tx MXene nanofillers to improve the compatibility and CO2/CH4 separation performance of cellulose triacetate (CTA)-based MMMs. CTA-based MMMs with TiO2-based 1D (nanotubes) and 0D (nanofillers) additives were also fabricated and tested for comparison. The high thermal stability, compact homogeneous structure, and stable long-term CO2/CH4 separation performance of the CTA-2D samples suggest the potential application of the membrane in bio/natural gas separation. The best results were obtained for the CTA-2D sample with a loading of 3 wt.%, which exhibited a 5-fold increase in CO2 permeability and 2-fold increase in CO2/CH4 selectivity, compared with the pristine CTA membrane, approaching the state-of-the-art Robeson 2008 upper bound. The dimensional (shape) effect on separation performance was determined as 2D > 1D > 0D. The use of lamellar stacked MXene with abundant surface-terminating groups not only prevents the aggregation of particles but also enhances the CO2 adsorption properties and provides additional transport channels, resulting in improved CO2 permeability and CO2/CH4 selectivity.

Interfacial polarization effects on dielectric properties in flax reinforced polypropylene/strontium titanate composites

Interfacial polarization or Maxwell-Wagner-Sillars effect using a dielectric study with the addition of strontium titanate and flax fiber reinforcement on a polypropylene matrix were investigated. Scanning electron microscopy (SEM) was performed for characterizing the fabricated sample to identify its fibers, ceramic, and polymer matrix regions. In the presence of strontium titanate and flax fiber reinforcement, the SEM images show signs of small ceramic agglomerates with fewer voids on fiber surfaces and a homogeneous distribution of fillers in the polymer matrix. The dielectric measurements revealed that dielectric relaxation occurs at low temperatures. The interfacial polarization was modeled using the Havriliak-Negami function, whereas the theoretical calculation shows a good best fit line with the experimental ones. The interfacial relaxation strength showed an increase of 202.54% from neat polypropylene matrix to flax reinforced polypropylene-strontium titanate composite from 0.866 to 2.62, respectively. This increase in dielectric strength is attributed to the accumulation of charge carriers at polypropylene-flax, polypropylene-strontium titanate, and strontium titanate-flax fiber interfaces. The potential use of these materials is in layered printed circuit board applications.

Styrene butadiene rubber and barium hexaferrite based flexible elastomer –inorganic dielectric systems

Flexible organic–inorganic composites of Styrene-butadiene rubber (SBR)/Barium hexaferrite (BHF, BaFe 12 O 19 ) have been prepared with different weight percentages (0 phr, 2.5phr, 5phr, 10phr) by solution casting method. The BHF was first prepared by sol–gel auto combustion method by using 'urea and ethylene glycol. The phase quantification and structural analysis were carried out through the Rietveld refinement of the X-ray diffraction of synthesized BHF particles with MAUD software having a low sig value. After the confirmation of the BHF structure, the SBR/BHF polymer composites of different phr were synthesized. And all these composites were thoroughly characterized by using different techniques. The uniform distribution of filler particles in the SBR polymer matrix is confirmed by the X-ray diffraction pattern. The homogeneous distribution of filler in the SBR polymer matrix at different phr was confirmed by SEM study. The influence of filler loading (0–10 phr), frequency (1 kHz-1 MHz), and temperature (25 °C-100 °C) on the electrical and dielectric properties of polymer ceramic composite was studied. The magnitude of capacitance and the resistance were calculated from the simulation of the Nyquist plot with an equivalent circuit.

Influence of graphene oxide on the static and dynamic mechanical behavior of compatibilized polypropylene nanocomposites

Abstract Graphene oxide (GO) is a carbon-based filler which possesses superior properties for the preparation of polypropylene (PP) nanocomposites. The homogeneous dispersion of nanofiller in a polymer matrix involves a compatibility between base and matrix. This research work analyzes the behavior of GO and its distribution in PP as well as the morphological, physical and mechanical properties of prepared nanocomposites. Since PP is non-polar and GO is polar, there may be a compatibility mismatch between filler and matrix, which may not lead to homogeneous distribution due to poor chemical interaction. Maleic-anhydride grafted polypropylene (MA-g-PP) was selected as a suitable compatibilizer in order to disperse filler into the matrix. X-ray diffraction (XRD) reveals an increase in intergallery spacing which confirms the formation of GO. Scanning electron microscopy (SEM) shows the improved distribution of GO sheets in the PP matrix for the compatibilized system. Tensile strength and modulus of elasticity are improved for the compatibilized PP nanocomposites when compared to the uncompatibilized and to the pure system. Moreover, an enhancement of storage modulus was evidenced for compatibilized nanocomposites. Polar-polar interaction between GO and compatibilizer leads to the homogeneous distribution of filler into the matrix which is clearly responsible for an improvement in the technical properties of polymer.

Thermally conductive high‐density polyethylene as novel phase‐change material: Application‐relevant long‐term stability

ABSTRACTThe long‐term stability of thermally conductive high‐density polyethylene (HDPE)‐based compounds as phase‐change material (PCM) is investigated. For this purpose, the HDPE's thermal conductivity (TC) is first enhanced via compounding two different filler types (expanded graphite and aluminum) into the polymeric matrix. Bulky specimens of these compounds are then stored in air for up to 7289 h in the melt state to investigate the compounds' long‐term stability as PCM. Their thermo‐oxidative/thermal stability and their ability to maintain the isotropic material character (homogeneous distribution of the incorporated particles) is investigated. The compounds' degradation behavior is monitored via Fourier‐transform infrared spectroscopy and the maintenance of the homogeneous filler distribution is examined via a combined differential scanning calorimetry/thermogravimetric analysis mapping of each exposed specimen. The storage capacity decreases minimally after 7289 h of exposure. Furthermore, the incorporated filler particles enhance the thermo‐oxidative stability of HDPE as PCM. Consequently, thermally conductive HDPE is a highly interesting PCM. © 2019 The Authors. Journal of Applied Polymer Science published by Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48269.

Leverage of machining parameters and non-oxide nano ceramic fillers loading on machinability of aluminium matrix based nano-composites

The research work in this article, deliberately discussed the machining behavior of Al7075 filled silicon carbide (SiC) and boron carbide (B4C) nanocomposites. Initially, the subjected composites were developed using ultrasonic cavitation assisted casting method and the dry turning experiments have been performed as per the Response surface methodology (RSM) Box-Behnkens design. The input variables were considered as cutting speed, feed rate, depth of cut and percentage reinforcement, respectively. After that, the microstructure, surface roughness and cutting forces were evaluated with analysis of variance (ANOVA) and regression analysis. In the end, the multi-objective optimization of process parameters was performed by using desirability analysis. The micrographs of developed nanocomposites indicate the refinement in the grain size of Al7075 nanocomposites with an increase in reinforcement quantity and homogeneous distribution of fillers throughout the matrix. Similarly, the analyzed results demonstrated that feed rate is the most influential input parameter which affects the output responses (surface roughness, main cutting force) whereas cutting speed has minimum effect on output responses. It has been also observed that strength of nano-composites increase with increase in filler loading, thereby enhancing the main cutting force and deteriorating the surface quality of nanocomposites.

The effect of multilayered film structure on the dielectric properties of composites films based on P(VDF-HFP)/Ni(OH)2

High dielectric constant ceramics fillers are widely used as fillers in polymer matrix to prepare high performance dielectric composites. Homogeneous filler distribution in these composites films is found to be quite difficult to achieve balance between high dielectric constant and high breakdown strength. Herein, multilayer structured composites films containing nickelous hydroxide (Ni(OH)2) as fillers, with different multilayered structures were designed and prepared, including 2–5 layers structure with various filler distribution. The effects of multilayer structure on the dielectric performance are explored by keeping the overall filler content constant. Combined with computer simulation, it is suggested that the variation in filler distribution in these films can effectively redistribute electric field intensity. Meanwhile, the dielectric constant and breakdown strength of the overall composites can be adjusted by changing the volume ratio between high filler content layer and low filler content layer. It is noted that at least 1/3 of the overall film volume should be occupied by a high breakdown strength layer to keep rather high overall breakdown strength. Moreover, high dielectric constant layer should be the outer layers to achieve overall high dielectric constant. Among all the layered structures investigated, the maximum energy density of 6.03 J/cm3 is obtained for film with a 3-layer nonsequential arrangement structure, which is 68% higher than single layer film with identical composition. This study provides some reference value for the preparation of multilayered dielectric polymer composites films for energy storage applications.

Influence of Ambient Temperature and Light-curing Moment on Polymerization Shrinkage and Strength of Resin Composite Cements.

The purpose of this study was to establish a clinically appropriate light-curing moment for resin composite cements while achieving the highest indirect tensile strength and lowest polymerization shrinkage. Polymerization shrinkage of seven resin composite cements (Multilink Automix, Multilink Speed Cem, RelyX Ultimate, RelyX Unicem 2 Automix, Panavia V5, Panavia SA plus, VITA Adiva F-Cem) was measured at ambient temperatures of 23°C and 37°C. Testing was done for autopolymerized and light-cured specimens after light application at either 1, 5, or 10 minutes after mixing. Indirect tensile strength of all cements was measured after 24 hours of storage at temperatures of 23°C and 37°C, for autopolymerized and light-cured specimens after light application 1, 5, or 10 minutes after mixing. To illustrate filler size and microstructures, SEM images of all cements were captured. Statistical analysis was performed with one-way ANOVA followed by post hoc Fisher LSD test ( α=0.05). Final polymerization shrinkage of the resin composite cements ranged from 3.2% to 7.0%. An increase in temperature from 23°C to 37°C as well as the light-curing moment resulted in material dependent effects on the polymerization shrinkage and indirect tensile strength of the cements. Polymerization shrinkage of the cements did not correlate with the indirect tensile strength of the cement in the respective groups. Highest indirect tensile strengths were observed for the materials containing a homogeneous distribution of fillers with a size of about 1 μm (Multilink Automix, Panavia V5, VITA Adiva F-Cem). The magnitude of the effect of light-curing moment and temperature increase on polymerization shrinkage and indirect tensile strength of resin composite cements is material dependent and cannot be generalized.

Optimization of mechanical properties of glass‐spheres‐filled polypropylene composites for extrusion‐based additive manufacturing

Polypropylene (PP) parts produced by extrusion‐based additive manufacturing (EB‐AM) suffer from warpage issues due to their high degree of crystallinity and orientations introduced during printing. These issues can be overcome by the addition of spherical fillers. However, the low aspect ratio of the filler and high filling degrees necessary for preventing warpage downgrade the mechanical properties, especially the toughness. This study aims at optimizing a PP‐compound containing spherical glass microspheres for the application in EB‐AM by maximizing the matrix–filler compatibility and therefore the printability, tensile properties and toughness, while still counteracting dimensional inaccuracies. A detailed study on the tensile, fracture, thermal, rheological, and impact properties of various compounds containing different glass types was conducted. It was shown that for EB‐AM applications, PP compounds based on borosilicate glass spheres outperform compounds filled with the conventionally used inorganic soda lime glass. The proposed optimized composite exhibits an exceptional interfacial adhesion between the microspheres and the matrix and a homogeneous filler distribution. It offers an improved processability and tensile properties up to the yield point comparable to those of neat PP. In a concluding impact test on printed composites, the optimized system exhibited impact energies 80% higher than compounds containing the conventionally used glass. POLYM. COMPOS., 40:638–651, 2019. © 2017 Society of Plastics Engineers

Evaluation of Filler Effects on the Dynamic Mechanical Behavior of HTPB-Elastomer Used as Binder in Exemplary Composite Formulations

This study aims to evaluate the dynamic mechanical properties of a binder, used in composite propellants, with increasing amount of different solid fillers. Dynamic Mechanical Analysis (DMA) is performed to determine the region of glassrubber transition temperature (Tg). Further parameters were obtained from the description of the loss factor curves (tanδ) with models based on exponentially modified Gauss (EMG) distribution function. Polyurethane binders employing the polyol HTPB and diisocyanate were filled with 20,40,and 60 mass-% of ammonium perchlorate (AP), aluminum (Al) or cyclotrimethylene trinitramine (RDX) particles, using fine and coarse mean sizes. A special turning device manufactured by Fraunhofer ICT was installed inside the curing oven in order to avoid sedimentation during curing. The cured composites were characterized by DMA in torsion mode from ‑100 °C to 70 °C. The good homogeneous distribution of fillers in the samples was evaluated by computational X-ray micro-tomography. The data on tanδ showed a complex structure describable at first with 2 overlapping peaks. The peak at lower temperatures is due to mobility of unrestricted binder parts (Tg unr) and the second broader peak at high temperature is due to mobility of restricted binder parts (Tg res). Results of tanδ, calculated areas of EMG curves and apparent activation energies of the distinct relaxation processes indicate that Al particles have higher interaction with HTPB-based polyurethane than AP and RDX. Probably Al is bonded to the binder network via isocyanate coupling with OH groups present in the surface. Ammonium perchlorate and cyclotrimethylene trinitramine particle sizes and its morphology influenced the viscoelastic properties. AP and RDX cause more changes in intensity of first peak of loss factor than Al. Increasing amount of these both particles enhances storage (G’) and loss (G”) shear moduli. As a whole tanδ intensity is lowered in the main peak and Al showed an intensity increase in the second apparent peak.

Composite anion exchange membranes with functionalized hydrophilic or hydrophobic titanium dioxide

Composite anion exchange membranes based on polysulfone with grafted 1,4-diazabicyclo[2.2.2]octane (DABCO) and surface functionalized TiO2 nanoparticles were prepared and characterized. Tri(hydroxymethyl)propane (TMP) was used for hydrophilic and polymethyl-hydrosiloxane (PMHS) for hydrophobic surface functionalization. Thermal analysis (TGA and DSC) showed water loss, the loss of quaternary ammonium groups around 300 °C and the backbone decomposition above 400 °C starting from the quaternary carbon. The decompositions were confirmed by temperature-dependent FTIR spectroscopy. The thermomechanical study (DMA) showed a secondary relaxation, probably due to DABCO side groups motions, around 130 °C followed by the glass transition around 250 °C and by a partial crystallization of the polymer, which is also observed by DSC. The increase of storage modulus observed for the composites is consistent with their reduced hydration, which is confirmed by water uptake measurements. Atomic Force Microscopy observations show a more homogeneous dispersion of hydrophobic TiO2 nanoparticles, which are also well embedded in the polymer, whereas agglomeration is evident for hydrophilic surface treatment. The contact angle with water decreases strongly in composites with TMP-TiO2. The ionic conductivity is higher for PMHS-TiO2, probably related to the more homogeneous filler distribution with lower agglomeration.

Improvement of the flame retardancy of plasticized poly(lactic acid) by means of phosphorus‐based flame retardant fillers

SummaryThe aim of this study is to improve the flame resistance and toughness of poly(lactic acid) (PLA) with the addition of low amount of flame retardant fillers and plasticizer simultaneously. Poly(ethylene glycol) (PEG) was used as plasticizer for PLA. Ammonium polyphosphate, boron phosphate, and tri‐phenyl phosphate (TPP) were used as flame retardant additives. Among these flame retardant additives, boron phosphate was synthesized from its raw materials by using microwave heating technique. Characterization of PLA/PEG‐based flame retardant composites was performed by conducting tensile, impact, differential scanning calorimeter, thermal gravimetric analysis, scanning electron microscope, limiting oxygen index, and UL‐94 vertical burning tests. Mechanical tests showed that the highest tensile strength, impact strength, and elongation at break values were obtained with the addition of ammonium polyphosphate and TPP into PLA/PEG matrix, respectively. Scanning electron microscopy analysis of the composites exhibited that the more homogeneous filler distribution in the matrix was observed for TPP containing composite. The best flame retardancy performance was also provided by TPP when compared with the other flame retardant additives in the plasticized PLA‐based composites.

Strong and ductile graphene oxide reinforced PVA nanocomposites

Graphene oxide (GO) and its derivatives have been widely used as reinforcement in polymer matrices for enhanced mechanical and electrical properties. While graphene has higher elastic modulus and tensile strength than that of graphene oxide, it is the latter’s hydrophilic nature that provides a distinct advantage as a filler in the aqueous processing of polymer nanocomposites. In this work, we have tried to disseminate the effects of GO and reduced graphene oxide (rGO) as fillers in polyvinyl alcohol (PVA) matrix. At a loading of only 0.3 wt% GO in PVA, we observed ∼150% increment both in elastic modulus and tensile strength, which is unprecedented. The property enhancement was attributed to the homogeneous distribution of fillers, and strong interfacial interactions (hydrogen bonds) between the fillers and the matrix. Composites fabricated after in-situ reduction of GO fillers had elastic modulus comparable to that of pure PVA, but had considerably improved tensile strength. The failure strain of rGO based composites was much higher than that of both pure PVA and GO reinforced PVA composites, thus showing enhanced ductility. The microstructure of the PVA-rGO composites exhibited alignment of the fillers in the plane of the polymer film, with interfacial bonds between the fillers and matrix only at the rGO sheet edges. The distribution of GO fillers in the PVA-GO composites, however, was random with no preferred orientation. A higher degree of interfacial interactions and the homogeneous distribution of the fillers led to enhanced elastic modulus and strength, along with considerable ductility for the PVA-GO composites.

"Patchy" Carbon Nanotubes as Efficient Compatibilizers for Polymer Blends.

Surface-modified carbon nanotubes (CNTs) have become well-established filler materials for polymer nanocomposites. However, in immiscible polymer blends, the CNT-coating is selective toward the more compatible phase, which suppresses their homogeneous distribution and limits harnessing the full potential of the filler. In this study, we show that multiwalled CNTs with a patchy polystyrene/poly(methyl methacrylate) (PS/PMMA) corona disperse equally well in both phases of an incompatible PS/PMMA polymer blend. Unlike polymer-grafted CNTs with a uniform corona, the patchy CNTs are able to adjust their corona structure to the blend phases by selective swelling/collapse of respective miscible/immiscible surface patches. Importantly, the high interfacial activity of patchy CNTs further causes a significant decrease in PMMA droplet size with increasing filler content. The combined effect of compatibilization and homogeneous distribution makes patchy CNTs interesting materials for polymer blend nanocomposites, where next to the compatibilization, a homogeneous filler distribution is important to gain the desired materials property (e.g., reinforcement).

Glass Ionomer Cement – Development and Characterization Microstructural

The Glass Ionomers Cements (GICs) are materials widely used in dentistry, have advantages such as fluoride release and chemical adhesion to the dental substrate. They are recommended as a restorative material, luting agent in prosthetic dentistry and also in medicine. However, there is need for developing new bone cements as an alternative or replacement to the current polymethylmethacrylate cements, therefore, the objective of this research was to develop an experimental GIC and characterization regarding morphology, chemical composition and crystallinity. This composite was characterized by X-ray diffraction (XRD), Infrared Spectroscopy Fourier Transform (FTIR) and optical microscopy (OM). For comparative study, was used the GIC Vidrion R (SS White) in the control group. These cements are presented in semi-crystalline diffraction patterns, the FTIR spectra observed characteristic bands of these materials and microstructural study of the cements showed homogeneous distribution of filler in the polymer matrix, corroborating with the literature.

Tendencies in the development of the technology of composite materials based on glass/glass-ceramic matrices and discrete fillers

Present-day scientific and patent literature concerned with ways and problems of obtaining glass/glass-ceramic composite materials with discrete fillers are reviewed. Theoretical aspects of developing materials of this kind are considered, and the most widely used and alternative technologies are described. It is shown that there is a tendency toward application of powder technology due to the simplicity of its implementation. The problem of providing a homogeneous distribution of fillers within a matrix and ways of its solution are considered. The closest attention is given to composite materials based on carbon nanotubes. Various ways to mold and thermally treat composite materials are described, their advantages and disadvantages are considered. It is shown that the spark-plasma sintering (SPS) technique, named electropulse method by domestic authors, is the most promising. The main presently existing problems in the technology of glass/glass-ceramic composite materials are presented.

Effect of titanium dioxide nanoparticles on mechanical properties of vinyl ester-based nanocomposites

The incorporation of nanoparticles into a polymer can lead to a considerable improvement of mechanical properties. Especially, the toughness and stiffness of the nanocomposite can be enhanced at the same time. Therefore, a homogeneous distribution of fillers within the matrix is required. In this research study, the feasibility of improving polymer composites was investigated using 21 nm titanium dioxide nanoparticles in a vinyl ester resin. The nanocomposites were processed by shear mixing and ultrasonication at different filler concentrations (1, 2.5, and 5 wt%). Also, a polymeric coupling agent was employed to strengthen the interface between filler and resin by forming strong chemical bonds. Changes in mechanical properties were examined through a variety of tests. Results indicate an enhancement in the vinyl ester composite mechanical properties due to the addition of small fraction of titanium dioxide particles. It was concluded that the highest mechanical properties could be achieved at an optimal titanium dioxide fraction.