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This study presents a novel multi-technique approach that integrates micro-CT and optical photothermal infrared spectroscopy (O-PTIR) to evaluate polymerisation differences, so-called spatio-temporal polymerisation properties, between flowable and sculptable dental resin-based composites. Ten commercially available dental composites were investigated, including flowable and sculptable counterparts from the same manufacturer. Eight parameters were evaluated: short-term polymerisation characteristics (degree of conversion after 5 min, maximum polymerisation rate, time to reach maximum polymerisation rate) was measured using ATR-FTIR with real-time monitoring; changes in the degree of conversion with depth were evaluated with O-PTIR, 3D visualisation of shrinkage patterns, overall volumetric shrinkage, depth-specific shrinkage, and porosity were measured using micro-CT; surface morphology with detailed measurements of elemental composition was characterised using SEM/EDX; light transmittance was analysed with a NIST-referenced spectrometer. The study found that the increase in filler weight and volume ratio reduced the degree of conversion and polymerisation shrinkage, while moderately influencing the maximum polymerisation rates. The time to reach maximum polymerisation rates and light transmittance were not dependent on the filler amount. O-PTIR assessed a depth-dependent decrease in the degree of conversion for both composite types, with flowable composites generally showing a greater decrease in the degree of conversion than sculptable composites, except for bulk-fill composites. Micro-CT scans showed significantly higher flowable shrinkage values than their sculptable counterparts, highlighting the performance differences between the two types of composites. The findings of this study have practical implications for the selection and use of dental composites. Flowable composites, despite their higher degrees of conversion and polymerisation rates, also exhibit higher volumetric shrinkage, which can be detrimental for clinical applications. The new measurement methods used in this study provide a comprehensive overview of the polymerisation behaviour of commercially available dental composites, offering valuable insights for material optimisation. [ABSTRACT FROM AUTHOR]

Dental resin composites' performance is intricately linked to their polymerisation shrinkage characteristics. This study compares polymerisation shrinkage using advanced 3D micro-computed tomography (micro-CT) and traditional 2D linear assessments. It delves into the crucial role of filler content on shrinkage and the degree of conversion in dental resin composites, providing valuable insights for the field. Five experimental dental composite materials were prepared with increasing filler contents (55–75 wt%) and analysed using either 3D micro-CT for volumetric shrinkage or a custom-designed linometer for 2D linear shrinkage. The degree of conversion was assessed using Optical Photothermal Infrared (O-PTIR) and Fourier-Transform Infrared (FTIR) spectroscopy. Light transmittance through a 2-mm layer was evaluated using a NIST-calibrated spectrometer. Scanning Electron Microscopy (SEM) and Energy-Dispersive X-ray Spectroscopy (EDX) examined surface morphology and elemental distribution. Correlation between the investigated parameters was determined using Spearman correlation analyses. The study found significant differences in polymerisation-related properties among different filler content categories, with volumetric shrinkage consistently demonstrating higher mean values than linear shrinkage across most groups. Volumetric shrinkage decreased with increasing curing depth, showing no direct correlation between filler content and shrinkage levels at different curing depths. The results highlighted a strong negative correlation between filler content and degree of conversion, volumetric and linear shrinkage, as well as maximum shrinkage rate. Light transmittance showed a moderate correlation with the filler content and a weak correlation with other tested parameters. This study underscores the importance of considering both volumetric and linear shrinkage in the design and analysis of dental composite materials. The findings advocate optimising filler content to minimise shrinkage and enhance material performance. Integrating micro-CT and O-PTIR techniques offers novel insights into dental composites' polymerisation behaviour, providing a foundation for future research to develop materials with improved clinical outcomes. • 3D micro-CT and O-PTIR spectroscopy provide novel insights into dental composite polymerisation. • Filler content significantly influences polymerisation shrinkage and degree of conversion. • Volumetric shrinkage was consistently higher than linear shrinkage in most experimental groups. • Increasing filler content reduced shrinkage and improved material performance. • Integration of micro-CT and O-PTIR techniques advances understanding of dental composites. [ABSTRACT FROM AUTHOR]

Polymeric encapsulation or packaging materials have gained great significance on efficacy and reliability of light-emitting diodes (LEDs). In one of the four-wheeler applications, headlamp illumination issue was observed due to failure of LED polymeric coating during the running condition. In the present work, a set of characterization techniques were employed to identify the root causes of LED failure caused by the delamination of polymeric encapsulation coating and provided the possible remedies. For root cause analysis and further failure prevention, field failure LEDs and defect-free LEDs were analyzed. The LED coating was scratched from field failure and defect-free LEDs surface, and set of characterization methods have been employed for chemical, thermal, mechanical, and morphological analysis. The filler loading and their dispersion played major role in delamination of the polydimethylsiloxane (PDMS) coating. From the set of experiments, it was observed that the delamination of the coatings was caused by the higher filler content and their random dispersion. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were used to analyze the thermal characteristics of LED coatings. Scanning electron microscopy (SEM) and polarized optical microscopy (POM) were used to explore the morphological analysis of LED coatings. SEM and TGA analysis confirmed the presence of titanium dioxide (TiO2) filler and concentration in the PDMS coating. The concentrations and dispersions of titanium dioxides principally showed the major influence on defected and defect-free LED coatings. [ABSTRACT FROM AUTHOR]

The application of natural material excavates from wood source in composite production has increased taking the merit of low cost, readily available and light weight. The objective of this study was to evaluate the effects of particle size and filler content on the mechanical properties of avocado wood flour-low density polyethylene composite (AWF-LDPE) modified with NaOH/CH3C00H using Response Surface Methodology. The influence of process parameters (size and weight of avocado wood flour (AWF)) on the properties (elongation, flexural strength, flexural modulus and impact strength) of the produced composite was evaluated. The AWF was injected at the size of particles from 20-100 mesh (850-150 µm) and flour content of 5-25 % wt into low-density polyethylene (LDPE) matrix to produce the composite of AWF-LDPE by the process of the injection molding machine. The optimization for the process parameters and mechanical properties of the composites was done using central composite design (CCD) of response surface methodology. The optimum condition for the factors and the properties of the composite were forecast with regression models of CCD. The ultimate process conditions for the process variables were 100 mesh size and 25 % wood flour content, while the properties were 4.8768 % elongation, 41.2921 MPa flexural strength, 0.6614 GPa flexural modulus and 83.384 KJ/m2 impact strength. The coefficient of determinations (R2 ) was close to unity with the maximum error of 0.09139 %. The values obtained from the AWF-LDPE composite at optimum condition indicated that it is recommended for suitable material for particle board in interior part of appliances and automobile application. [ABSTRACT FROM AUTHOR]

In the injection molding process, weld line regions occur when a molten polymer flow front is first separated and then rejoined. The position, length, and angle of weld lines are dependent on the gate location, injection speed, injection pressure, mold temperature, and, especially, the direction and degree of the polymer melt velocity in the mold-filling process. However, the wall surface velocity of the thermoset melt in the mold-filling process is not zero, which is not found for thermoplastic injection molding. The main reason leading to this difference is the slip phenomenon in the filling phase between the thermoset melt and the wall surface, which is directly affected by the filler content. In this study, commercial thermoset phenolic injection molding compounds with different amounts of filler were employed to investigate not only the mechanism of weld line formation and development behind an obstacle in the injection molding process but also the flow disturbance of the thermoset melt in the spiral flow part. In addition, the effect of the wall slip phenomenon on the flow disturbance characterization and the mechanism of weld lines of selected thermoset materials was carefully considered in this research. Furthermore, the generated material data sheet with the optimal developed reactive viscosity and curing kinetics model was imported into a commercial injection molding tool to predict the weld line formation as well as the mold-filling behavior of selected thermoset injection molding compounds, such as the flow length, cavity pressure profile, temperature distribution, and viscosity variation. The results obtained in this paper provide important academic knowledge about the flow disturbance behavior as well as its influence on the mechanism of weld line formation in the process of thermoset injection molding. Furthermore, the simulated results were compared with the experimental results, which helps provide an overview of the ability of computer simulation in the field of the reactive injection molding process. [ABSTRACT FROM AUTHOR]

This study investigated the tensile properties and thermal behavior of virgin and hot press molded HDPE composites filled with different particle size and content of used beverage cartons which were the Tetra Pak® cartons. The mechanical properties of the composites were positively influenced by particle size of the used beverage carton, such that the smallest particle size gave the highest tensile strength and tensile modulus. The tensile strength of the specimens decreased with increasing filler content (40 to 70 wt%), while the tensile modulus rose. Furthermore, the filler size and its content affected the thermal behavior of the specimens. Calorimetry analysis of composite specimens showed that melting temperature and enthalpy values of virgin HDPE and recycled-HDPE decreased with increasing Tetra Pak® content. In all composite groups produced by adding Tetra Pak®, the degree of crystallinity decreased as a function of Tetra Pak® addition compared to the pure HDPE. Increasing particle size adversely affected the crystallization degree, which decreased with increasing particle size while the HDPE maintained its crystalline form. As for the recycled-HDPE composites, the degree of crystallization was reduced by increasing the Tetra Pak® content, but this was still noticeably higher than that of the HDPE.

Waste paper, the use of which is increasing day by day as a raw material, has a heterogeneous structure as it contains non-fiber material from different sources. It is desired to have a homogeneous product when recycled. Within the scope of this study, the SEM images of the raw materials determined according to EN 643 standard and the products made with the recycling of these raw materials were examined, ash content, fines content and ash on sieve were stated and the results obtained by determining filler content (removed) and fiber fines (removed) were discussed. While the samples with the highest ash content were H3 and U3, the lowest samples were H6 and U9. It was determined that the samples with the highest fines content were H2 and U1, while the lowest samples were H4 and U2. While the samples with the highest ash on sieve were H3 and U3, the samples with the least were determined as H2 and U9. The filler content was highest in H1 and U3 samples, while the lowest was in H6 and U9 samples. The samples with the most fiber fines were found as H2 and U9, and the least as H1 and U3 samples. [ABSTRACT FROM AUTHOR]

(1) Background: This study evaluates the effect of a conventional/low-voltage light-curing protocol (LV protocol) (10 s with 1340 mW/cm2) and high-voltage light-curing protocol (HV protocol) (3 s with 3440 mW/cm2) on the microhardness (MH) of dental resin-based composites (RBCs). Five resin composites were tested: conventional Evetric (EVT), Tetric Prime (TP), Tetric Evo Flow (TEF), bulk-fill Tetric Power Fill (PFL), and Tetric Power Flow (PFW). (2) Materials and Methods: Two tested composites (PFW and PFL) were designed for high-intensity light curing. The samples were made in the laboratory in specially designed cylindrical molds; diameter = 6 mm and height = 2 or 4 mm, depending on the type of composite. Initial MH was measured on the top and bottom surfaces of composite specimens 24 h after light curing using a digital microhardness tester (QNESS 60 M EVO, ATM Qness GmbH, Mammelzen, Germany). The correlation between the filler content (wt%, vol%) and the MH of the RBCs was tested. For the calculation of depth-dependent curing effectiveness, the bottom/top ratio for initial MH was used. (3) Conclusions: MH of RBCs is more dependent on material composition than on light-curing protocol. Filler wt% has a greater influence on MH values compared to filler vol%. The bottom/top ratio showed values over 80% for bulk composites, while for conventional sculptable composites, borderline or suboptimal values were measured for both curing protocols. [ABSTRACT FROM AUTHOR]

This study investigated the tensile properties and thermal behavior of virgin and hot press molded HDPE composites filled with different particle size and content of used beverage cartons which were the Tetra Pak® cartons. The mechanical properties of the composites were positively influenced by particle size of the used beverage carton, such that the smallest particle size gave the highest tensile strength and tensile modulus. The tensile strength of the specimens decreased with increasing filler content (40 to 70 wt%), while the tensile modulus rose. Furthermore, the filler size and its content affected the thermal behavior of the specimens. Calorimetry analysis of composite specimens showed that melting temperature and enthalpy values of virgin HDPE and recycled-HDPE decreased with increasing Tetra Pak® content. In all composite groups produced by adding Tetra Pak®, the degree of crystallinity decreased as a function of Tetra Pak® addition compared to the pure HDPE. Increasing particle size adversely affected the crystallization degree, which decreased with increasing particle size while the HDPE maintained its crystalline form. As for the recycled-HDPE composites, the degree of crystallization was reduced by increasing the Tetra Pak® content, but this was still noticeably higher than that of the HDPE. [ABSTRACT FROM AUTHOR]

A completely opposite injection molding filling behavior of thermosets and thermoplastics by an effective and useful method developed by the authors was found. Specifically, for the thermoset injection molding, there is a strong slip between the thermoset melt and wall surface, which is not found for the injection molding of thermoplastic materials. In addition, the variables, such as the filler content, the mold temperature, the injection speed, and the surface roughness that could lead to or influence the slip phenomenon of thermoset injection molding compounds, were also investigated. Furthermore, microscopy was conducted to verify the correlation between the mold wall slip and fiber orientation. The results obtained in this paper open challenges in the field of the calculation, analysis, and simulation of mold filling behavior of highly glass fiber-reinforced thermoset resins in the injection molding process with consideration of wall slip boundary conditions. [ABSTRACT FROM AUTHOR]

Summary: The purpose of this research was to evaluate the influences of filler type and its content on the performance of a water‐based intumescent fire‐retardant coating. Three fillers (vermiculite, celite, and aluminum hydroxide) were added to the intumescent paint formulation. The thermal and fire protective properties were studied with thermogravimetric analysis (TGA), torch test, electrical furnace, scanning electron microscopy (SEM), and Fourier transform infrared analysis (FTIR). The results showed that adding fillers into coatings up to 3% could improve the intumescent coating's behavior and increase its endurance against flames. Of the three fillers used, vermiculite showed a better performance in the torch test, attributed to its chemical and physical structure. Vermiculite has low thermal conductivity and is considered an appropriate filler for heat‐insulation. The final back‐plate temperatures in the torch test for the vermiculite‐containing samples were around 100°C–150°C lower than that of other samples. Moreover, vermiculite's addition improved the coating's expansion by 10% compared with the control sample's. The vermiculite sample's char layer morphology showed a uniform cell size distribution, indicating structural robustness. The coating samples successfully transformed polypropylene flammability from highly flammable to V0 level in the UL 94 vertical burning test standard. The results showed that vermiculite could improve intumescent paint's fire resistance and be used as an enhancer in intumescent coating formulations. [ABSTRACT FROM AUTHOR]

Green biocomposites based on poly (3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) reinforced with Agave Americana fibers (AAF) were elaborated by melt compounding at various fiber content ratios, that is, 10, 20, and 30 wt.%. Morphology before and after tensile testing, rheological, viscoelastic, mechanical, and thermal properties of the biocomposite samples were investigated with respect to the AAF content. Tensile and DMA data showed a significant increase in both Young's modulus and storage modulus of PHBHHx biocomposites with the AAF content, however, more relevant at 30 wt.%. However, a slight decrease in tensile strength and strain at break was observed, while thermal stability remained almost unchanged whatever the AAF content. The study highlighted the reinforcement effect of AAF in PHBHHx biocomposite materials, in particular at filler content of 30 wt. %. Graphical Abstract [ABSTRACT FROM AUTHOR]

Herein, we describe the latex compounding preparation of activated calcium silicate (ACS)/styrene‐butadiene rubber (SBR) composites aiming to improve filler dispersibility. The effects of ACS particle size and filler content on the vulcanization, static mechanical properties, and thermal stability of composite materials were evaluated. FT‐IR analyses showed that the rubber macromolecules were chemically adsorbed on the surface of the ACS particles, while SEM and TEM indicated that the ACS particles were uniformly distributed in the composites, and agglomeration occurred only at high filler content levels. ACS particle size reductions accelerated composite vulcanization, whereas increasing filler content had the opposite effect. ACS particles strengthened the mechanical properties of prepared composites, with marked increases in tensile strength and tear strength as ACS particle size decreased and filler content rose, reaching maximal values of 15.37 MPa (increased by 932%) and 45.91 kN/m (increased by 425%), respectively, at an ACS average particle size of 1 μm and 90 phr loading. ACS particle integration also enhanced composite thermal stability. These data indicate that ACS enhances rubber composites owing to the incorporation of well‐dispersed ACS particles into the rubber matrix, strong interactions between ACS particles and rubber molecules, and the thermal barrier effects of these particles. [ABSTRACT FROM AUTHOR]

This work reports on the effect of the particle size of almond shell powder (ASP) filler on starch-based biodegradable polymer. Different size ranges of particles were studied: < 0.05 mm, 0.05–0.08 mm, 0.08–0.125 mm and 0.125–0.250 mm in biocomposites with 30 wt% ASP. Additionally, biocomposites with 5 wt%, 10 wt% and 20 wt% of filler were prepared with ASP of 0.08–0.125 mm particle size. Biocomposites were manufactured by extrusion-compounding, and test samples were produced by injection moulding with the aim to study mechanical and thermal properties. The possibility of implementing the developed biocomposites in traditional industries, such as toys or packaging was evaluated, as biodegradable materials have gained great industrial interest in recent years owing to the coming legislative requirements and/or due to customer demands. The addition of the ASP on the polymeric matrix increases the stiffness of the polymer and reduces the deformation at break, the impact strength and the thermal stability. On the other hand, the final natural aesthetics provided by the filler is highly appreciated by the manufacturers and consumers (Blasco in Consumer attitudes and toy trends for eco-babies and bio-parenting, Nuremberg, 2020; Baeza in Childcare trends 43–45, 2020). The results of the study showed that, the filler content had a more significant effect than the particle size on the mechanical properties of the biocomposites. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate a novel approach for measuring the polymerization shrinkage of dental resin composites – measurement of sample depth variation. This new method was compared with two testing methodologies used for assessing the polymerization shrinkage (buoyancy and strain gauge methods). Eleven commercial resin composites were investigated (EverX Posterior; EverX Flow Bulk & Dentin; G-aenial Anterior, Posterior, A'chord & Universal Injectable; Filtek One Bulk Fill & Universal Restorative; SDR + Flow and Aura Bulk Fill). In addition, filler content (wt. %), flexural modulus, and the degree of conversion were evaluated. Shrinkage values, obtained by the buoyancy method, are greater than shrinkage evaluated by the strain gauge. There are significant differences in polymerization shrinkage among the tested resin composite materials. There is a strong correlation between the newly proposed method of shrinkage measurement and the buoyancy method (r2 = 0.8; p < 0.01). There is no correlation between volumetric shrinkage measurement (depth changes and buoyancy method) and linear strain measurement. Volumetric filler amount correlates with shrinkage values evaluated by all three methods. The degree of conversion for the tested resin composites ranges from 36 % to 52 %. There are some differences (around 10 %) between the filler content (wt. %) measured by the ashing-in-air method and the data given by the manufacturers. The highest flexural modulus is 14.8 GPa and the lowest 6.6 GPa. New formulations may introduce unknown relationships between the fundamental properties of dental resin composites. [Display omitted] • Depth change measurements can be used to evaluate the shrinkage of resin composites. • Depth change measurements and buoyancy method are strongly correlated. • There is no correlation between linear and volumetric shrinkage. • Strong correlations are observed between filler amount (vol%) and shrinkage values. • Degree of conversion correlates with linear shrinkage. [ABSTRACT FROM AUTHOR]

In this study, BisGMA and TEGDMA as monomers were used to fabricate dental composites. Camphorquinone was used for photopolymerization using LED light curing unit. To prepare filled resin based dental composites, different wt. % (5, 10, 15, and 20) of nanosilica were used. Unfilled and filled samples were prepared to test for volumetric wear. To access the effect of filler content, normal load, sliding velocity and number of cycles using L25 orthogonal array, wear tests were performed on pin-on-disc apparatus using different levels of process parameters. Using Taguchi methodology and ANOVA, volumetric wear is analyzed, and it is revealed that the filler content is the most significant parameter which affects volumetric wear of nanosilica filled dental composites. [ABSTRACT FROM AUTHOR]

Mastic, a compound consisting of an asphalt binder and a mineral filler, is an important ingredient in asphalt mixtures, as it is responsible for critical adhesion and viscoelasticity. The rheological properties of mastic are strongly correlated with the rutting potential of asphalt pavement. To explore the impact of filler on the rheological response, three types of asphalt binders and eight types of filler contents were used to fabricate the mastic samples. A modified version of multiple stress creep recovery (MSCR) test selected in this study was regarded as a superior protocol by which to test the rutting potential of asphalt binder and mastic. Based on the rheological behaviour, the 1.0 mm parallel plate gap height was recommended for use in the dynamic shear rheometer (DSR) to evaluate mastic in the MSCR test. The test yielded excellent results with regard to modifier contents, filler contents and stress levels. The regression analysis proved that percent recovery (%R) was a better index for estimating the rheological ability of mastic. Based on the results for %R, the linear viscoelastic region of modified mastic could be expanded by increasing the filler content, while neat mastic demonstrated poor recovery under high stress regardless of filler content. Based on the rheological response, the recommended filler contents were 100%, 120% and 50% for the mastics with 4.0% SBS-modified binder, 3.5% SBS-modified binder and neat binder, respectively. [ABSTRACT FROM AUTHOR]

We study a tensile property test was conducted to investigate the mechanical behavior of nylon-6 and its composites. The wear conduct of Nylon-6 loaded up with nanometer measured boron nitride (BN) composites has been explored for changing filler content, normal load, sliding distance and speed with three levels of every parameter according to Taguchi’s design of experiment. A pin-on-disk compose erosion and wear test (ASTM G99) was utilized to assess wear conduct of Nylon-6/BN polymer composites. The significant commitments of this work are the decline of extreme quality with expanding substance of boron nitride in the composites and the normal load converted to 71.54% of variety in the wear rate. To improve the mechanical properties of Nylon-6/BN composites will enhance the application of pure comparative the pure Nylon-6.

Polymer matrix composites with embedded ferroelectric and/or piezoelectric particles, constitute a novel and interesting class of engineering materials. The incorporation of ferroelectric and/or piezoelectric particles within a polymer matrix is expected to add functionality to the resulting composite, due to the variation of polarisation of the ceramic particles with temperature. In this work, an elastomeric matrix such as polydimethylsiloxane and BaTiO(3) nano and microparticles were used for the fabrication of composites at various concentrations and sizes of the reinforcing phase. Morphological and structural characteristics were investigated via scanning electron microscopy images and X-ray diffraction patterns. The dielectric behaviour of all fabricated specimens was investigated via broadband dielectric spectroscopy, in a wide frequency (10^−1 Hz–10 MHz) and temperature (30–200°C) range. In the dielectric spectra, two relaxation processes were detected, namely cold crystallisation and interfacial polarisation. Values of dielectric permittivity enhance with filler content, and particles’ size, while diminishes significantly with frequency. Finally, the ability of the prepared systems to store energy was examined by calculating their energy density. The higher energy-storing efficiency is exhibited by the micro-BaTiO(3) reinforced composites, while functional behaviour is induced via the thermally activated structural changes of ferroelectric particles.

Car tires, sealing caulk and high-voltage cable insulators are prime examples of commercially available and widely used composites of polymers containing nanostructured particles. In fact, myriads of applications can be realized but the usefulness of such nanocomposites depends heavily on composition, morphology, concentration and dispersion homogeneity of the nanoparticle filler in the polymer matrix. Optimizing these characteristics while ensuring economically feasible fabrication, determines the extent to which new products integrate nanocomposites. This review discusses challenges and manufacturing options of polymer nanocomposites and, in particular, which and how much nanoparticle fillers improve electrical/thermal conductivity, dielectric permittivity, gas permeability, magnetization and mechanical stability by critically reviewing and classifying over 280 peer-reviewed articles. Lastly, the economic, environmental and health implications associated with these materials are highlighted.

Calcium carbonate (CaCO3) is an important filler, widely used rubber industries, particularly in natural rubber latex dipped such as gloves. The main advantages are cost reduction and product improvement. With the development of technology in superfine filler production, the use of CaCO3 as a non-reinforcing filler has gained much attention as it could help to improve natural rubber (NR) product properties. In this study, mixed clones of natural rubber field latex (MCFL) were prepared before further processing into mixed clones' natural rubber latex concentrate (MCLC). The properties of MCLC were evaluated before compounds with CaCO3 and other rubber chemicals. The MCLC films were prepared from the MCLC added with CaCO3 varied from 10 to 40 parts per hundred rubber (pphr) and rubber chemicals. The total protein contents for unaged and aged latex films before and after acetone extraction was determined, respectively, according to total nitrogen (N) and extractable protein (EP) contents. The content of CaCO3 in MCLC films at different loadings was characterised by a Thermogravimetric analyser (TGA). Meanwhile, mechanical properties such as tensile and tear strengths were also determined. It was found that the total protein contents for the unaged MCLC films at different filler loadings were higher as compared to the aged samples. It is also proposed that the chemicals' interference for MCLC films have occurred from 25 pphr until 40 pphr filler loadings. The tensile strength of MCLC films decreased as the filler loading increased. However, the tear strength of MCLC films increased as the filler loading increased. [ABSTRACT FROM AUTHOR]

FSSW is a solid state joining method gained its significance as an alternate welding technique in the in electrical, electronic and automobile industries that used FSW welding. FSSW can be used to welding dissimilar joints of material with variation in metallurgical and mechanical characteristics. In this paper, dissimilar welding joints of aluminum alloys (5052) and pure copper (10100) with a thickness of 1.67 mm were welded by FSSW. The variation of rotational speed, dwell time and filler content have been used. The welding joints has been examined by tensile shear test. The scanning electron microscope SEM and X-ray diffraction are used to investigate the hook and intermixing layer characteristics. It was found the best welding condition is (1400 rpm) and (30 sec) which the joint is possess the tensile shear force (3340 N). Adding ZnO filler led to increase the thickness of the copper hook, and expanding the stir zone (weld width bond). Joints with V2-ZnO have highest thickness of intermixing layer (IM), length of weld width bond and best tensile shear force (4300 N). [ABSTRACT FROM AUTHOR]

Poly(lactic acid)/bacterial cellulose nanocomposites were prepared by solvent casting. Aiming to reduce the incompatibility between polar bacterial cellulose (BC) and the nonpolar poly(lactic acid) (PLA) matrix which induces filler aggregation and poor reinforcement dispersion, BC was acetylated by the use of a non-conventional route catalyzed by citric acid. The derivatized BC (AcBC) was incorporated into de PLA matrix at varying filler loadings, and optical, morphological, structural, thermal, tensile and barrier (water vapor) properties of PLA/AcBC in comparison with PLA/BC were evaluated. Noticeable changes in the nanocomposite properties were ascribed to the success of the route proposed to surface hydrophobize BC, which significantly improved its dispersibility within the PLA matrix and the matrix-filler interaction. By the way, the variation of filler loading allowed attaining remarkable increases in the nanocomposite films stiffness without significant reductions in tensile strength and water vapor permeability. [ABSTRACT FROM AUTHOR]

Objective: To investigate the effect of filler content on microtensile bond strength (µ-TBS) in Class I cavities. Methods and Materials: Experimental composites with filler contents of 80%, 76%, 70%, 60%, and 50% by weight were used. Polymerization shrinkage was measured with Acuvol, and a three-point flexural test was performed to determine flexural properties. For evaluation of µ-TBS, 25 extracted human molars were randomly divided into five groups and Class I cavities were prepared. After filling with one of the experimental composites and curing for 40 seconds, teeth were serially sectioned perpendicular to the cavity floor. Stick-shaped samples were tested with a microtensile tester. Statistical analysis was conducted using ANOVA and Pearson correlation tests. Results: Significant correlations were found between filler content and polymerization shrinkage (r = -0.973, P< .05) and the filler content and Young modulus (r = 0.891, P< .05). Different filler contents in the experimental composites had no significant effect on µ-TBS or flexural strength. Conclusion: In a Class I cavity model, this in vitro study showed that the filler content did not influence the flexural strength of experimental composite resins and had no effect on the microtensile bond strength between composite resin and dentin. [ABSTRACT FROM AUTHOR]

Nanoparticles of MnO2 with different shapes (needle-like α-MnO2 and spherical δ-MnO2) were proposed as promising fillers for electrorheological fluids (ERFs). A thorough study of the dielectric properties of α-MnO2 and δ-MnO2 suspensions in silicone oil enabled estimation of the values of their dielectric permittivity and dielectric relaxation times. The study of MnO2-filled materials with various filler contents, and under various electric field strengths, in shear and uniaxial tensile and compressive stress regimes, revealed that needle-like α-MnO2 nanoparticles, in comparison with spherical δ-MnO2 particles, lead to better mechanical properties of the fluids. The most intriguing property of MnO2-based electrorheological fluids is their high electrorheological response at low filler content: ERF containing only 4.5 vol.% of α-MnO2 in silicone oil demonstrated a 18 kPa tensile strength in a 5 kV electric field. [ABSTRACT FROM AUTHOR]

Epoxy nano passivated aluminium composites with optimised size and filler contents were fabricated. Variation in contact angle and surface roughness is insignificant with increasing filler into nanocomposites but it showed a drastic reduction on corona ageing. Water droplet initiated corona inception voltage (CIV) is high under the negative DC voltage followed with positive DC and AC voltages. The bandwidth of ultra‐high frequency signal generated due to water droplet initiated corona discharge lies in the range of 0.5–1.2 GHz. Surface potential measurements have shown that the decay in the potential was fast initially, and it became slower and sluggish subsequently. The trap energy density versus trap depth plot exhibits shallow traps and deep traps at around 0.8 and 0.87 eV, respectively. Permittivity, conductivity and loss factor have increased with an increase in the filler content in nanocomposites. The bulk resistance and capacitance of samples were determined for obtaining the equivalent parallel RC circuit model. Incorporation of nanofillers increases the glass transition temperature and reduces the tan δ with increasing frequencies as evident from dynamic mechanical analysis studies. A direct correlation is observed between the plasma temperature measured through laser‐induced breakdown spectroscopy spectra and hardness of the material. [ABSTRACT FROM AUTHOR]

Studying of paper carriers of information has become increasingly important in forensic practice. This is caused by growing number of bogus or in other manner fraudulently alternated documents. An identification of individual paper sheets and studying their differences are the parts of forensic analysis of multiple sheets documents. This paper focuses on the possibilities of processing of mathematical and statistical data obtained by measurements of FT-IR spectral characteristics of individual paper sheets in a studied document. The spectral data were used to create data matrix which contains values of absorbance and interval of wavenumber. The method of differentiation is based on the comparison of maximum absorbance values within the range of wavenumbers from 1562 to 1215 cm−1. This spectrum range is specific in occurrence of absorption bands that belong to calcium carbonate CaCO3—an element of paper added into it in relatively high amounts in the form of filler which content or percentage occurrence may be different considering to the paper producer or production technology. Based on the above-said, the paper sheets originating from different producers or from various production technology units can be differentiated one from another using a robust statistical analysis. [ABSTRACT FROM AUTHOR]

In this study, blends of poly (caprolactone) (PCL) with different content of coir fibre (CF) (2, 2.5 and 5 wt%) were fabricated by solvent casting technique to obtain a biodegradable composite. The PCL/CF composites obtained have been characterised using the X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and Electrodynamic fatigue testing machines. According to XRD patterns, the intensity of the peak in the pure PCL spectrum was found to decrease by the addition of coir fibre which then disappears when the CF content is 5 wt% is indicating that coir fibre inhibited the diffusion and deposition of PCL molecules. The FTIR absorption spectra for the PCL/CF blends showed that there was no new peak to represent the chemical interaction between the functional groups of coir fibre and poly (caprolactone). The SEM micrographs of the composites indicate inadequate wetting of coir fibre as filler content increases due to poor dispersion and interfacial adhesion. The tensile strength of the composites samples was found to increase with an increase in the fibre content up to 2.5 wt% on addition of coir fibre but with a reduction from 16.79 N/mm2 for the neat polymer to 5.08 N/mm2 for the blend with 5 wt% coir fibre (a 69.74% decrease). The addition of coir fibre reduces the elongation at break of the composites, whereas the Young modulus value of composites goes on increasing up to 182 N/mm2 for coir fibres volume fraction of 2.5 wt%. The behaviour of samples with high fibre content could be explained by insufficient fibre wetting and poor interfacial adhesion with no coupling agent in addition to the low aspect ratio of the coir particles. [ABSTRACT FROM AUTHOR]

Poly-L-lactide (PLLA) and hydroxyapatite/poly-L-lactide (HAp/PLLA) are two widely used biomaterials for three-dimensional scaffolds, drug release matrices and implantable medical devices for reparation of bone tissue; diversity in the initial preparation and filler content has a significant influence on different properties such as morphology and crystallinity, thus playing a considerable role in most of these applications. For this reason, PLLA and HAp/PLLA samples with a large difference in crystallinity (from below 20% to over 70%) and filler content (up to 86 wt% of HAp nanoparticles with an average diameter of 80 nm) were prepared and consequent dissimilarities in morphology, crystallinity and thermal properties were investigated by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), wide angle X-ray diffraction (WAXD) measurements and Fourier transform infrared (FTIR) spectroscopy. Special attention was devoted to analyzing data obtained from thermal measurements. A three-phase model was employed in order to describe the heat capacity step decline in the nanocomposite; the evolution in different polymer fractions, the crystalline fraction and the mobile and rigid amorphous fractions, with filler content was determined. [ABSTRACT FROM AUTHOR]

The blending effect (BE) plays an important role in esthetics of the composite resin. The objective of this study was to determine the extents to which filler size and content affect the BE. Three types of fillers (0.7, 1.0, and 1.5 µm) were mixed at weight contents of 60, 70, 75, and 80%. This study simulated clinical class 3 or 4 cavities and quantitatively measured the color diffusion of the objects next to the cavities based on the CIELab color space. For each filler size, there was a trend of increasing BE as the filler content was increased. The translucency parameter (TP) exhibited the opposite trend of decreasing (p<0.05) with increases in filler content. The filler size did not affect the BE, and the different filler sizes produced statistically non-significant results in this study. Increases in filler content elevated the opacity of the composite resin and significantly influenced the BE. [ABSTRACT FROM AUTHOR]

Paper production requires large amounts of cellulosic fiber, whereas the world’s forested lands and croplands have a finite capacity to supply such resources. To deal with likely future pressure on forest resources, as well as to hold down costs of materials, publications examined in the preparation of this review suggest that the paper industry will need to implement several concurrent strategies. In particular, the industry can be expected to view recycling as a central part of its activities. Basis weights of various paper-based products can be expected to decrease over the coming decades, and more of the fiber content will be replaced with fillers such as calcium carbonate. Such trends will place intense demands upon chemical-based strategies to enhance the bonding within paper and paperboard. Based on the literature, further progress in reducing the amount of new forest resources used to meet a given set of paper product requirements will require a combined approach, taking into account various fiber attributes, nanostructures, novel concepts in bond formation, and advances in the unit operations of papermaking.