Filler In Poly Research Articles

Synthesis of Substituted Octacalcium Phosphate for Filling Composite Implants Based on Polymer Hydrogels Produced by Stereolithographic 3D Printing

Based on theoretical and experimental analysis of ionic equilibria in buffer solutions, we have found conditions for octacalcium phosphate (OCP), Ca8(HPO4)2(PO4)4 ∙ 5H2O, synthesis. Succinate-substituted OCP, Ca8(HPO4)2–хSucx(PO4)4 ∙ 5H2O, with x = 0.8–0.9 has been synthesized at pH 5.5 and t = 60°C in 3 h via α-TCP hydrolysis in a 0.25 M succinic buffer solution. The synthesis product is more stable to thermolysis than is pure OCP: the apatite-like product is stable up to 630°C. The succinate@OCP powder has been used as a filler for poly(ethylene glycol)diacrylate-based hydrogel in producing a composite implant by stereolithographic 3D printing.

UV-Absorbing Gallic Acid Derivatives as Functional Reinforcing Fillers in Poly(Vinyl Chloride) Films

The poly(vinyl chloride) PVC was photostabilized by gallic acid derivatives (0.5% by weight). The photodecomposition rate constant was reduced significantly in the existence of gallic acid derivatives along with PVC (blank). R1 compound was found to be the most effective stabilizer in photostabilization of PVC. The photodecomposition rate constant for PVC films containing R1 was found to be 1×〖10〗^(-4) compared to 8×〖10〗^(-4) sec-1 for PVC films in the absence of any additives. Different mechanisms of photostability for PVC films that involve gallic acid derivatives have been proposed.

Biomechanical and Acoustic Energy Harvesting from TiO2 Nanoparticle Modulated PVDF Nanofiber Made High Performance Nanogenerator

An integrated platform made with a piezoelectric nanogenerator (NG) is designed to convert daily human activities and acoustic vibration into useable electrical energy. The titanium dioxide (TiO2) nanoparticles (NPs) are playing a significant role as external fillers in poly(vinylidene fluoride) (PVDF) electrospun nanofiber that improves the overall performance of the NG. It effectively enhanced the piezoelectric β-phase content (16% higher F (β)) and mechanical (148% increment of tensile strength) properties of composite PVDF nanofiber. The superior integration of NG has been demonstrated to generate electricity from a human gait. The acoustic sensitivity and energy conversion efficiency are found to be 26 V Pa–1 and 61%, respectively, which are superior in comparison to the reported results. By scavenging the mechanical energy, NG is capable of charging up a 1 μF capacitor; for example, ∼20 V is within 50 s that ensures its ability to power up commercial LED tape and a LCD screen. Thus, in this work, a ...

Lignin and holocellulose from pecan nutshell as reinforcing fillers in poly (lactic acid) biocomposites

Lignocellulose from agro-food biowaste represents a valuable source of cost-effective structural fillers for wholly renewable polymer composites. In this work, pecan (Carya illinoinensis) nutshell (NS) fiber and its structural components, holocellulose (HC) and acid insoluble lignin (AIL), were isolated, characterized and used as reinforcing fillers to manufacture poly(lactic acid) (PLA) based biocomposites. Thermal, morphological and mechanical properties of the prepared materials were analyzed. NS and HC acted as heterogeneous nucleating agents, potentially able to control PLA physical aging. Moreover, they significantly enhanced the viscoelastic response of PLA, mainly restricting the melt molecular mobility due to hydrodynamic effects and the formation of a three-dimensional particulate network. Flexural tests demonstrated that HC induced a 25% increase in modulus compared to the plain polymer. AIL, conversely, conferred higher ductility to the PLA matrix producing an increase in stress and strain at break of 55% and 65%, respectively. Finally, all the biocomposites showed lower resilience with respect to plain PLA due to the lack of chemical adhesion between filler and matrix. These results emphasize the potential of NS as a source of reinforcing filler in polymer-based biocomposites.

Synergistic effect of nano-ceria dispersion on improvement of Li+ ion conductivity in polymer nanocomposite electrolytes

In the present work, we report a polymer-nanocomposite electrolyte (PNCE) system by dispersing CeO2 nano-powders as fillers in Poly(ethylene)oxide-LiClO4 matrix. The ceria powders known for their redox and catalytic activity have strongly influenced the structural properties of the PNCEs. XRD and thermal analysis results suggest structural modification in PNCEs that leads to improved ionic conductivity. The maximum conductivity of ∼3.0 × 10−5 S cm−1 is observed for 1–2 wt% and 10 wt% nano-CeO2 dispersed PNCEs. The d.c. conductivity and hopping frequency are thermally activated. The activation energy of d.c. conductivity (Ea) and ion hopping (Em) are well correlated, suggesting that PNCEs with smaller interaction energy between Li+ ions and PEO offer better ionic conductivity.

UV-Absorbing Cellulose Nanocrystals as Functional Reinforcing Fillers in Poly(vinyl chloride) Films

Ultraviolet (UV)-responsive poly(cinnamoyloxy ethyl methacrylate) (PCEM) was grafted on cellulose nanocrystals (CNCs) via the surface-initiated atom transfer radical polymerization technique. The resultant PCEM-grafted CNCs (PCEM-g-CNCs) exhibit high UV absorption properties and undergo cross-linking when subjected to UV radiation. When the PCEM-g-CNC nanohybrids were incorporated into poly(vinyl chloride) (PVC) matrix, transparent nanocomposite films with UV-blocking characteristics were obtained. Comparison of the optical and mechanical properties of the films before and after UV irradiation confirmed that the PCEM-g-CNCs are excellent thermal and UV stabilizers for PVC. In addition, the tensile properties of the PVC film were increased significantly and further enhanced after UV irradiation.

Silver-Decorated Boron Nitride Nanosheets as an Effective Hybrid Filler in PMMA for High-Thermal-Conductivity Electronic Substrates.

High-thermal-conductivity and low-dielectric-loss polymer nanocomposites have gained tremendous attention in microelectronics technology. Against this background, the present study deals with the development of a high-thermal-conductivity, low-dielectric-constant, and low-loss polymer nanocomposite based on silver nanoparticle (AgNP)-decorated boron nitride nanosheets (BNNSs) as the filler in poly(methyl methacrylate) (PMMA) matrix. The nanocomposites were prepared through a facile solution-blending process. Elemental mapping of the prepared nanocomposite indicates the uniform distribution of filler particle in PMMA matrix. An impressive high-thermal conductivity (TC) enhancement of around 363% was achieved for nanocomposite of 0.35 Vf of hybrid filler (1.48 W/m K) compared to pristine PMMA (0.32 W/m K). The addition of AgNP reduces the thermal contact resistance (Rc) by bridging individual BNNS, thereby improving thermal transport. Measured TC values were fitted with a theoretical model that showed good agreement. Dielectric measurements performed at radiofrequencies and microwave frequencies revealed that the nanocomposites show a low dielectric constant (<5), low loss (10–2), and very low alternating current conductivity (10–7 S/cm). The results suggest that silver-decorated BNNS is a promising hybrid filler for effective thermal management.

Utilization of Polyaniline (PAni) as Conductive Filler on Poly (Ethylene Oxide) / Poly (Vinyl Chloride) Films: Effects of Naphthalene as Surface Modifier on Electrical Conductivity

The aim of the study was to utilize polyaniline (PAni) as conductive filler in poly (ethylene oxide) / poly (vinyl chloride) (PEO/PVC) films. Naphthalene was used as surface modifier to increase the properties of PEO/PVC/PAni films. The electrical conductivity of PEO/PVC/PAni film improved with higher loading of PAni until it reached the percolation threshold at 10 wt%. Moreover, the conductivity of the films also improved with the addition of naphthalene compared to the films without naphthalene. These enhancements were due to the improved interfacial bonding between PEO/PVC blend and PAni, which were supported by scanning electron microscopy (SEM) analysis. In addition, no new chemical bonding was created with the incorporation of naphthalene as proved by the FTIR analysis.

Magnetoelectric investigations on poly (vinylidene fluoride)/CoFe2O4 flexible electrospun membranes

Flexible and free standing magnetoelectric polymer nanocomposite electrospun membranes, which exhibit both ferroelectric and magnetic orderings simultaneously, are fabricated. CoFe2O4 nanoparticles of different weight percentages are embedded as fillers in poly (vinylidene fluoride) (PVDF) matrix. The percentage of electroactive β phase is analysed using XRD and FTIR studies. Investigations on the effect of filler on the structural, functional, morphological properties are discussed. CoFe2O4 content in PVDF plays a main role in controlling the α and β phase conformations and makes significant effect on the ferroelectric and ferromagnetic properties of PVDF/CoFe2O4 membranes. The domain switching behaviour of these ferroelectric membranes is confirmed through DC-EFM studies. In addition to the coexistence of ferroelectric and ferromagnetic orderings, the cross coupling between them have been proved.

Characterization of poly(lactic acid) biocomposites filled with chestnut shell waste

The aim of this study was to determine thermal and mechanical properties and applicability of ground chestnut shell waste as a filler for poly(lactic acid) composites. The used amount of filler was ranging from 2.5 to 30 wt%. Spectroscopic analysis of composites and its ingredients was conducted by means of FT-IR method. The mechanical and thermal properties of the composites were determined in the course of static tensile test, Dynstat impact strength test, DMTA analysis, and DSC method. The fractured surface morphology of biocomposites was evaluated by SEM analysis. Incorporation of the filler influenced the overall mechanical properties of the composites characterized by high stiffness and lowered impact resistance. Fabricated composites with different amounts of non-reactive natural waste filler exhibited acceptable mechanical and thermal properties. Therefore, these composites can be used as eco-friendly, biodegradable materials for low-demanding applications.

Polymer-based nanocomposites employing Bi2S3@SiO2 nanorods for high dielectric performance: Understanding the role of interfacial polarization in semiconductor-insulator core-shell nanostructure

Advanced polymer-based dielectric composites are core materials in the electronics and power systems. Construction of core-shell architectures has been proved as a powerful strategy to dramatically enhance the dielectric and energy storage performances. Herein, core-shell structured amorphous SiO2 encapsulating Bi2S3 nanorods with varying shell thickness were employed as the fillers in poly(vinylidene fluoride) (PVDF) matrix, affording a Bi2S3@SiO2/PVDF nanocomposite. The dielectric behaviors of Bi2S3@SiO2/PVDF composites with varying SiO2 shell thickness as a function of filler loading in comparison with Bi2S3/PVDF were studied. Bi2S3@SiO2 core-shell structure dramatically suppressed the dielectric loss (<0.04) and decrease in conductivity yet maintaining high dielectric constant. Furthermore, adjusting Bi2S3@SiO2-PVDF interface by controlling the SiO2 shell thickness results in changing dielectric behaviors. The effects of SiO2 shell and the arising Bi2S3@SiO2 interface on the dielectric and electric properties were investigated via interfacial charge calculation based on Maxwell-Wagner-Sillars model. The role of semiconductor-insulator interfacial polarization in determining the dielectric behaviors of the composites were understood. Due to the greatly reduced dielectric loss, Bi2S3@SiO2/PVDF nanocomposites can withstand high electric field and the study on energy storage capacity and efficiency was realized in the polymer-based composite with conductive filler. This study demonstrates the robust effect of core-shell architecture in suppressing dielectric loss yet maintaining the high dielectric constant of the polymer-based composites, providing a promising route to achieve high-performance dielectrics.

A study of cryostructuring of polymer systems. 45. Effect of porosity of dispersed filler on physicochemical characteristics of composite poly(vinyl alcohol) cryogels

Composite cryogels simulating the properties of waterproof screens of hydraulic structures, such as protruding dykes and dams, have been obtained by a cryogenic treatment (freezing at –10…–30°C followed by incubation in the frozen state for 12 h and defrosting at a rate of 0.03°C/min) of suspensions of calcium-carbonate-containing (marble or coquina) or cellulose-containing (microcrystalline cellulose or sawdust) particles in aqueous poly(vinyl alcohol) solutions. Viscometric examinations of initial suspensions have shown that adhesion contacts arise between filler particles, as well as discrete and continuous phases, already at the stage of suspension preparation, thereby affecting the properties of resulting cryogels. This is most pronounced when high-porosity sawdust is used as a filler. It has been shown that all the dispersed materials used in the work are “active” fillers for poly(vinyl alcohol) cryogels, these fillers increasing the rigidity of the formed composites. Therewith, porous particles, into which the polymer solution can penetrate, are more efficient. The dependence of the composite rigidity on the temperature of the cryogenic treatment has, as a rule, a bell-shaped pattern with a maximum in the region of –20°C. Being tested for water permeability, the obtained model composite cryogels have exhibited pronounced antifiltration properties (the filtration coefficient is ≤(1–2) × 10–9 cm/s), thus indicating that such materials are promising for solving problems relevant to the protection of fascine hydraulic structures from erosion with snow water.

Improved mechanical and wear resistance properties of silicon carbide/poly (vinyl alcohol) composites by silane coupling agents

In this work, the surface coated silicon carbide (SiC) obtained by dispersing it in silane coupling agent/ethanol solutions of different concentrations was used as a filler in poly (vinyl alcohol)(PVA) and the composites of (PVA)/SiC were prepared by melt process. The structure and properties of PVA/SiC composites were studied by Fourier‐transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), scanning electron microscopy (SEM), mechanical and wear resistance tests in detail. The silane coupling agent was hydrolyzed under acidic conditions, and as a result, large number of hydroxyl and amino groups were generated, which could form hydrogen bonds with hydroxyl groups of the PVA molecular chains, this effect subsequently improved the interactions between the filler and matrix. The surface modified SiC particles dispersed well in PVA matrix resulting a good compatibility with the matrix. For the PVA/SiC composites with the same content of SiC filler, both tensile strength and elongation at break improved with the increase of silane coupling agent concentration. In addition, a good improvement in the wear resistance of the PVA/SiC composites was also achieved compared with the neat PVA/SiC composite. POLYM. COMPOS., 39:3849–3857, 2018. © 2017 Society of Plastics Engineers

Dielectric and mechanical properties of poly(butylene succinate) thin film composites incorporated with barium strontium titanate powder

ABSTRACTHigh dielectric constant barium strontium titanate (Ba0.7Sr0.3TiO3 or BST) powder was prepared by sol-gel method for using as a filler in poly(butylene succinate) (PBS) composite with 0–3 connectivity system. Moreover, thermal and dielectric properties of poly(butylene succinate) integrated with BST powder were studied. The results showed the success of improving thermal stability and dielectric constant of poly(butylene-succinate) by increasing amount of BST powder. Therefore, the prepared PBS-BST composite thin films with good dielectric properties, flexibility, and processability could be applicable for the thin film capacitor for high-frequency electronic devices.

Layered double hydroxides as fillers in poly(l-lactide) nanocomposites, obtained by in situ bulk polymerization

In this study in situ bulk polymerization of L-lactide filled with layered double hydroxides (LDH) was investigated. Four different LDHs intercalated with two different organic anions (salicylate and sebacate) were synthesized and characterized. After characterization, these synthetic layered compounds were used as fillers in poly(L-lactide) (PLLA) nanocomposites with two different fillers’s loadings (1 wt% and 2 wt%). PLLA and PLLA nanocomposites were evaluated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), ultraviolet and visible spectroscopy, thermogravimetric analysis (TGA), dynamical mechanical analysis (DMA), flexural testing and differential scanning calorimetry (DSC). The results demonstrated that, compared to PLLA, the nanocomposite containing 1 wt% of Zn/Al salicylate transmitted less UVA and UVB light, while keeping a similar transparency in the visible region. Thermogravimetric analysis revealed that the nanocomposite with 1 wt% of Zn/Al salicylate exhibited the highest thermal stability. In general the flexural and dynamical mechanical properties were reduced in compassion to neat PLLA. DSC results, demonstrated that, compared to PLLA, all the nanocomposites exhibited lower glass transition temperature and melting temperature values.

Improving the degradation behavior and in vitro biological property of nano-hydroxyapatite surface- grafted with the assist of citric acid

To obtain ideal nano-hydroxyapatite(n-HA) filler for poly(lactide-co-glycolide) (PLGA), a new surface-grafting with the assist of citric acid for nano-hydroxyapatite (n-HA) was designed, and the effect of n-HA surface-grafted with or without citric acid on in vitro degradation behavior and cells viability was studied by the experiments of soaking in simulated body fluid (SBF) and incubating with human osteoblast-like cells (MG-63). The change of pH value, tensile strength reduction, the surface deposits, cells attachment and proliferation of samples during the soaking and incubation were investigated by means of pH meter, electromechanical universal tester, scanning electron microscope (SEM) coupled with energy-dispersive spectro-scopy (EDS), fluorescence microscope and MTT method. The results showed that the introduction of citric acid not only delayed the strength reduction during the degradation by inhibiting the detachment of n-HA from PLGA, but also endowed it better cell attachment and proliferation, suggesting that the n-HA surface-grafted with the assist of citric acid was an important bioactive ceramic fillers for PLGA used as bone materials.

Modification of Eucalyptus and Spruce organosolv lignins with fatty acids to use as filler in PLA

Spruce (softwood) and Eucalyptus (hardwood) woods were used as raw material for lignin extraction by organosolv process. Chemical, structural and thermal characterizations of the extracted lignin samples have been performed using HPLC, GPC, FT-IR, 31P NMR, 13C NMR, DSC and TGA. Both lignins showed high purity, being Spruce lignin (OS) which presented the highest Klason lignin content (93%) and lowest sugar (0.5%) and sulphur (0.04%) content. Extracted lignin samples were chemically modified with dodecanoyl chloride fatty acid, in order to modify its thermal properties as glass transition temperature (Tg). The noticeable increase in the molecular weight and sharp decrease of Tg can be appreciated. Esterified lignins were used as filler in poly(lactic acid) (PLA) films elaborated by solvent casting in different concentrations (1, 5, 10, 25 and 50%). Mechanical, thermal and water barrier properties of prepared films were investigated. The results showed that the addition of both modified lignins contributed to greater ductility and lower stiffness, providing plasticity to PLA.

Structure of alumina-silica nanoparticles grafted with alkylphosphonic acids in poly(ethylacrylate) nanocomposites

Alumina-coated silica nanoparticles (NPs) grafted with phosphonic acids of different hydrophobicity were used as filler in poly(ethylacrylate) nanocomposites. Phosphonic acids bearing short alkyl chains or a diethylene glycol group have been grafted at densities up to 3.2 P/nm2 on NPs (20 nm) dispersed in water. Nanocomposites at particle fractions up to 10 vol% have been formulated by casting from the colloidal mixtures of modified NPs and nanolatex in water. The dispersion of the NPs in the polymer matrix has been studied by TEM combined with small-angle scattering, evidencing aggregation of NPs. TEM shows micrometer-scale inhomogeneities depending on the surface/polymer matrix compatibility. For the local interparticle correlations, a quantitative analysis of the intensity based on the mapping onto the effective structure factor of polydisperse hard spheres is developed. This mapping allows the model-free determination of the internal volume fraction of aggregates, termed compacity κ, to between 10% and 30%, compatible with the TEM analysis. κ is found to increase for the higher particle volume fractions, to decrease with grafting density, and to be mostly independent of the nature and mass of the graft. Preliminary evidence for an improved compatibility of grafted with respect to bare NPs is found, as opposed to their aqueous precursor suspensions where some pre-aggregation is induced by grafting.

Ultrafine fly ash as a reinforcing filler in poly(lactic acid) matrix

ABSTRACTFly ash, inexpensive and not eco‐friendly material, is the residue from the coal burning in thermal power stations. If ways can be found to use it, it will facilitate applications for the ash materials and simultaneously reduce the pollution. In this study, silane‐grafted ultrafine fly ash (S‐UFA) was used as a reinforcing filler in poly(lactic acid) (PLA) to prepare a series of PLA/S‐UFA composites. The tensile strength of PLA/S‐UFA composites increases with the increase of S‐UFA content when less than 20 wt %; after a loading fraction greater than 30 wt %, the tensile strength of the composites decreases with the increasing S‐UFA weight fraction. The morphology of PLA/S‐UFA composites was observed by scanning electron microscope (SEM). X‐ray diffraction (XRD) analysis was applied to investigate the crystal structure of S‐UFA and the composites. The thermal properties of these composites were studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The TGA results showed that the thermal stability of PLA/S‐UFA composites slightly decreased with the increasing S‐UFA loading fraction. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43716.

Preparation of dopamine-functionalized multi-wall carbon nanotube/poly(amide-imide) composites and their thermal and mechanical properties

Covalent functionalization of MWCNT-COOH with dopamine was conducted by microwave irradiation and the dopamine-functionalized MWCNTs (MWCNT-Dop) were used as fillers in poly(amide-imide) (PAI) to improve its thermal and mechanical properties. Results indicate that the MWCNT-Dop is dispersed in PAI very well, which is ascribed to a good interfacial interaction between the MWCNT-Dop and PAI by hydrogen bonding. The temperatures at which 10 wt% weight loss occurs, and the limiting oxygen indices increase from 398 to 483 oC and 35.5% to 41.5%, respectively, as the MWCNT-Dop content increases from 0 to 15 wt%. The tensile strength and Young's modulus also increase from 79.4 to 120.3 MPa and 2.0 to 3.3 GPa, respectively, as the MWCNT-Dop content increases from 0 to 15 wt%.