Solid Filler Research Articles

Sustainable PET Waste Recycling: Labels from PET Water Bottles Used as a Catalyst for the Chemical Recycling of the Same Bottles.

We report using a waste material, poly(ethylene terephthalate) (PET) water bottle labels, for the chemical recycling of the same PET water bottles. The solid fillers used for the manufacturing of the packaging labels were recovered by thermolysis in an electrical furnace at 600, 800, and 1000 °C with 13.5, 12.0, and 10.4 wt % recovery. Characterization of the solid residue showed the presence of calcium carbonate, calcium oxide, and titanium dioxide, which are typical fillers used for packaging film manufacturing, such as water bottle labels. These solid residues were then used as a catalyst for PET depolymerization by glycolysis, in which the catalyst recovered from bottle labels and shredded PET reacted in the presence of excess ethylene glycol at 200 °C. The reaction mixtures were analyzed for PET conversion and the yield of the bis(2-hydroxyethyl)terephthalate (BHET) monomer as the final product of the glycolysis reaction to determine the efficiency of the catalyst. Our results show that the catalyst prepared at 800 °C (Cat-800) has the best performance and provides a 100% PET conversion with a 95.8% BHET yield with a 1.0 wt % loading in 1.5 h. The catalyst from the PET water bottle labels is nontoxic, readily available, cost-effective, environmentally friendly, and can be used as a model for the self-sufficient chemical recycling of PET via glycolysis.

Digital light processing and electromagnetic wave absorption performance tuning of SiOC/SiO2 ceramics

SiOC ceramics have been applied to the fabrication of electromagnetic wave (EMW) absorbing metastructures by stereolithography and demonstrate excellent absorptivity due to the designability of the macrostructure. However, the pyrolysis of photosensitive polysiloxane preceramics may result in macroscopic cracking due to high mass loss and shrinkage. These factors can restrict the structural design flexibility. Combining high residual preceramics with appropriate solid phase fillers is one potential solution. In this study, two preceramics with high residual rates were physically blended with photosensitizing resins in various proportions. This was carried out with the objective of preparing photosensitized preceramics that have high ceramic yields and tunable dielectric properties in the final SiOC ceramics. Then, SiO2 fillers were incorporated into the photosensitive preceramics for the first time to reduce pyrolytic shrinkage and used to match the impedance matching properties of SiOC ceramics in order to enhance EMW absorption performance. The SiOC/SiO2 ceramics achieved a minimum reflection loss of −28.10 dB with a thickness of 1.90 mm. Additionally, the sample demonstrated an effective absorption bandwidth of 6.38 GHz at a thickness of 2.30 mm. The SiOC/SiO2 ceramics have potential applications in the rapid preparation of all-dielectric electromagnetic metamaterials, which exhibit the simplicity of the raw material preparation process and the wide effective absorption bandwidth with a high ceramics yield.

Study on Mechanical Properties and Failure Mechanisms of Highly Filled Hydroxy-Terminated Polybutadiene Propellant under Different Tensile Loading Conditions.

To study the mechanical properties of highly filled hydroxy-terminated polybutadiene (HTPB) propellant with 90 wt% solid fillers, the stress-strain curves of the propellant under different temperatures (-50 to 70 °C) and strain rates (0.000476 to 0.119048 s-1) were obtained by uniaxial tensile test. Moreover, to obtain the glass transition temperature and understand the effect of low temperatures on the mechanical properties of the propellant, DMA experiments were carried out. On this basis, the mechanical response laws of the propellant were analyzed, and the master curves of mechanical properties were established. Furthermore, the fracture features of the propellant under typical loading conditions were obtained by SEM, and the corresponding failure mechanisms were analyzed. The results show that the maximum strength decreases with increasing temperature, while the maximum elongation increases with increasing temperature at the same strain rate. The maximum tensile strength increases with increasing strain rate, while the maximum elongation decreases with increasing strain rate at the same temperature. The maximum tensile strength is lowest with a value of 0.35 MPa when the temperature is 343.15 K and the strain rate is 0.000476 s-1, at which time the maximum elongation reaches the highest with a value of 44%. In terms of failure mechanisms, the propellant shows no particle fracture, and the failure modes of the propellant are mainly matrix tearing and dewetting.

A coda wave interferometry to characterize and evaluate the powder debonding damage of solid propellant: Experimental investigation and discrete element simulation

The debonding of solid filler powder and binder matrix is the main form of damage for composite solid propellant. This study proposes a coda wave interference (CWI) analysis method to quantitatively characterize and evaluate the internal powder debonding damage of composite solid propellant by experiment and discrete element simulation. In order to verify the validity of numerical simulation, the discrete element method (DEM) samples to simulate the powder debonding damage of solid propellant are established, and the DEM simulation and micro-CT scanning experiment are carried out. The micro-experimental and DEM results prove the efficiency and accuracy of DEM samples in modeling the damage behaviors of solid propellant specimens. Furthermore, in order to quantitatively characterize and evaluate powder debonding damage of solid propellant, using CWI method to analyze the damage states of solid propellants in the experiment and DEM simulation of tension. Two coda evaluation parameters based on different damage states are proposed, and the relationship curves of coda evaluation parameters and tensile strain are obtained. Though the analysis of the curve results of experiment and DEM simulation, the validity of CWI is demonstrated. The coda evaluation parameters can quantitatively identify and judge the accumulation process of initial damage, the appearance of micro holes and the failure point of propellant.

A stretchable, environmentally tolerant, and photoactive liquid metal/MXene hydrogel for high performance temperature monitoring, human motion detection and self-powered application

Conductive gels have received extensive attention in flexible electronics due to their diverse characteristics. The requirement for versatility and incompatibility of the conductive fillers with the hydrogel matrix remain a challenge for hydrogels. Herein, the cellulose nanofiber stabilized liquid metal droplets are utilized to initiate the polymerization and simultaneously serve as solid conductive fillers to construct the polyacrylamide/MXene/glycerol hydrogel with eligible stretchability (1000%) and high environmental adaptability (−25 to 80 °C) for multifunctional sensing. The hydrogel is utilized as a flexible electrode to construct the triboelectric nanogenerator for mechanical energy harvesting and conversion as well as self-powered sensing. Importantly, as a versatile sensor, it combines temperature sensing and deformation sensing with a wide range of stimulus responses and exceptional sensing performance. The flexible temperature and strain sensors are realized with superior thermosensitivity and strain sensitivity. In addition, the hydrogel exhibits favorable photothermal antibacterial ability. This work opens new avenues for the preparation of photothermal, conductive, stress and thermal sensitive hydrogels for multimodal sensors, sketching a promising future for them in flexible and wearable electronics.

A Multiscale Hollow Spherical LATP Active Filler Improves Conductivity and Mechanical Strength in Composite Solid Electrolytes

The performance of composite solid electrolytes (CSEs) composed of poly(ethylene oxide) and ceramic oxide-type solid electrolyte fillers has been shown to be highly dependent on the available surface area of filler inside of the composite. This is due to the formation of new transport pathways in the polymer-ceramic interphase, a region some tens of nanometers between the bulk polymer and ceramic surface. The small volume of this interphase relative to the size of traditional particles presents a design problem: Using micron-scale filler particles, a nm-thick interphase can never occupy a meaningful volume fraction of the composite. Thus, nanoparticles are often used in CSEs. However, the inevitable agglomeration of nanoparticles prevents a continuous interphase from forming even in the best dispersion conditions. Therefore, efforts to explore and exploit this synergistic transport mechanism have so far relied on careful, slow, and expensive methods designed to yield a continuous polymer-ceramic interphase between electrodes, e.g., cast nanowires, infiltrated 3D-structures, or templating.In this work we report a ceramic solid electrolyte, Li1.3Al0.3Ti1.7(PO4)3 or LATP, with a multiscale hollow spherical microstructure, designed to maximize the available continuous interphase volume in the composite. The hollow spherical structure is achieved by synthesizing LATP particles onto 10-15 μm carbon spheres, then subsequently pyrolyzing the carbon to achieve micron-scale hollow spheres composed of nano-scale LATP particles. This structure effectively prevents the bulk agglomeration of individual LATP particles, while still allowing for long, continuous interphase pathways. Importantly, the non-directionality of the filler means that the manufacture of the films remains simple.The hollow spherical microstructure of the filler had significantly enhanced the room temperature conductivity of the composite solid electrolyte, to 1.64 x 10-4 S/cm – the highest reported for an LATP-containing CSE with micron-scale filler particles. The mechanical properties, thermal stability, and electrochemical stability of the composite solid electrolyte were also significantly enhanced. This approach is a promising method to exploiting the synergistic transport in composite solid electrolytes while maintaining their excellent manufacturability.

Evaluating and quantifying the variations and sensitivity in asphalt-filler interaction indices

The interaction within an asphalt-filler blend is usually defined by its volume filling and interfacial reciprocation tendencies. This interplay between a reinforcing solid filler within liquid asphalt thus ends up dictating the blend's transition point from a “diluted region” to a “concentrated region”, and the glass transitioning state of the asphalt itself. While prior studies focused on distinguishing asphalt-filler interactions based on composite reinforcement models, describing the definitive behaviour of its suffusing phase reciprocation has proved elusive. Hence, this study aims at redefining asphalt-filler interaction by evaluating and quantifying the varying distinctions in each established mastic composite model. Asphalt mastics composed of three distinct fillers of dolomite powder (DP), lime kiln dust (LKD), and ordinary Portland cement (OPC), along with a conventional PEN 60/70 binder, were blended together at 0.4, 0.8, and 1.2 filler to binder ratios (F/B) based on the Superpave mix dust to binder specification. The OPC mastic was regarded as the control mastic sample for all tests performed. A temperature sweep test was conducted on all prepared mastic test samples using dynamic shear rheometer equipment at varying temperatures of 46 °C, 52 °C, 58 °C, 64 °C, 70 °C, 76 °C, and 82 °C, for a controlled strain value of 5%, and an angular velocity of 10 rad/s. Asphalt-filler interaction was further analysed using evaluation index coefficients based on rheological performances, i.e., ΔG*, L-A-δ, K-B-δ, K-B-G*, and KE respectively. Variations in the evaluation coefficients obtained were also determined via statistical normality tests of skewness and kurtosis. Results obtained indicated a strong asphalt-filler interaction response for coefficients ΔG*, L-A-δ, K-B-G*, and KE, while K-B-δ exhibited inconsistent interaction responses. Similarly, the normality test results also inferred that ΔG*, L-A-δ, K-B-G*, and KE portrayed better skewness values compared to K-B-δ.

Multiscale microstructural consideration of enhanced shear strength in TiAl intermetallic/K4169 alloy composite joints prepared by vacuum brazing with (Ti, Zr)-Ni-based amorphous filler metal

TiAl intermetallic could be used to replace Ni-based alloy in assemblies to generate excellent specific strength. A (Ti,Zr)-Ni-based amorphous filler metal Ti21.25Zr25Ni25Cu18.75 (at.%) was designed using a cluster-plus-glue-atom model to successfully vacuum braze K4169 and TiAl bimetallic assemblies. At various brazing temperatures and holding time, the quantitative relationships between lattice distortion, grain boundary, dislocation density, and hardness, elastic modulus, shear strength of the joints were investigated. Meanwhile, the fracture mechanism of the joints was revealed. The brazed seam mainly consisted of solid diffusion reaction layers (Zones I and III) and filler metal residue zone (Zone II). When the brazing temperature increased to 1030 °C, grain refinement occurred in the brazed seam. Zone I was primarily composed of (Ni)ss[0-11]+TiNi[011]/(Cr,Fe,Ni)ss[0-11]/(Ti,Zr)Ni[0-1-1]+(Cr,Fe,Ni)ss[0-11]. The (Ti,Zr)(Ni,Cu)[001] and (Ti,Zr)(Ni,Cu)[101] intermetallic compound-based solid solutions were formed in Zone II. And the lattice distortion of (Ti,Zr)(Ni,Cu)[101] and (Ti,Zr)(Ni,Cu)[001] was 32.05% and 14.82%, respectively. As a result, the proportion of low angle grain boundaries (LAGBs) and deformed grains in Zone II rose to 38.6% and 38.7%. In Zones I and III, the proportion of LAGBs reduced to 8% and 3.4%, respectively. As the holding time increased, the long-range diffusion of Al in Zone II caused the (Ti,Zr)(Ni,Cu)[001] with cubic structure to transform into (Ti,Zr)(Ni,Cu,Al)[00-1] with hexagonal crystal system structure, where the lattice distortion was 4.42% and 10.49% for a and c. At 1030 °C/10 min, the average geometrically necessary dislocation densities (GNDs) in Zones I, II and III were 9.87 × 1014 m−2, 8.55 × 1014 m−2 and 11.4 × 1014 m−2, respectively. Therefore, the shear strength of joints reached 322 MPa due to the lattice distortion, dislocation strengthening and fine grain strengthening. Meanwhile, the plastic and brittle hard phases were generated in Zone II and displayed a mechanical interlocking structure that contributed to the performance of the joint. Both (Ti,Zr)(Ni,Cu)[001] and (Ti,Zr)(Ni,Cu)[101] in Zone II formed along different low-index cleavage planes during transgranular fracture. The cracks initiated in this region extended to the interface between Zones I and II and exhibited bimodal grain characteristics.

Removal of Solid Filler Particles from Composite with Polymer Matrix as a Factor of Abrasive Wear

Removal of Solid Filler Particles from Composite with Polymer Matrix as a Factor of Abrasive Wear

Corrosion Behavior and Simulation Analysis of Silicate Adhesive under High Temperature and Abrasion-Acid Environment

For studying the corrosion behavior and simulation analysis of silicate adhesive under high temperature and abrasion-acid environment, the corrosion behavior of silicate adhesive was tested with mechanical compression, scanning electron microscopic and X-ray diffraction (XRD), and analyzed under high temperature with finite element modeling. The results showed: under high temperatures and the abrasion-acid environment, the solid filler in the adhesive network structure will be exposed with the effect of particle wear. This will lead to a corrosion reaction between some fillers and hydrochloric acid, making dissolution loss. Large hollow holes will be formed at the loss part with the deepening of corrosion, the internal interconnection will occur, and the compression fracture curve characteristics of porous materials will appear, which will greatly reduce the compression strength of the materials. In special environments (temperature 200°C, flow rate 2m/s, and 31% concentration acid solution), hydrochloric acid corrosion is the control factor of silicate adhesive degradation.

Synthesis of multifunctional additives for solid propellants: Structure, properties and mechanism

To simplify the composite propellant formulation and address the current issue of the single-functionality present in existing additives, the multi-cyano, amine-based polybutadiene (AEHTPB-CN) was prepared based on AEHTPB by adopting appropriate synthesis strategies. By replacing 10% of HTPB binder in the propellant formulation, it can effectively enhance the interfacial bond strength between the propellant binder matrix and solid fillers (AP (ammonium perchlorate) and RDX (cyclotrimethylene-trinitramine)), the mechanical properties of the HTPB/AP/RDX/Al propellant were superior to blank control propellant with an improvement of 35.4% in tensile strength, 62.0% enhancement in elongation at break, and reduce the propellant burn rate by 10.7% with any energy loss. The function mechanism of AEHTPB-CN was systematically elucidated through experiments and computer simulation techniques. The results show that the tertiary amine group in AEHTPB-CN can react with AP to form ammonium ionic bonds, and the hydroxyl and cyano groups can form hydrogen bonding interactions with AP, which enables AEHTPB-CN to be firmly adsorbed on the AP surface through chemical and physical interactions. For RDX, the interfacial bonding effect of AEHTPB-CN is attributed to their ability to form C–H⋅⋅⋅NC weak hydrogen bonding interaction between the cyano group and RDX methylene group.

High-Strength Double-Network Conductive Hydrogels Based on Polyvinyl Alcohol and Polymerizable Deep Eutectic Solvent.

Conductive hydrogels feature the flexibility of soft materials plus conductive properties providing functionality for effectively sticking to the epidermis and detecting human activity signals. Their stable electrical conductivity also effectively avoids the problem of uneven distribution of solid conductive fillers inside traditional conductive hydrogels. However, the simultaneous integration of high mechanical strength, stretchability, and transparency through a simple and green fabrication method remains a great challenge. Herein, a polymerizable deep eutectic solvent (PDES) composed of choline chloride and acrylic acid was added to a biocompatible PVA matrix. The double-network hydrogels were then simply prepared by thermal polymerization and one freeze-thaw method. The introduction of the PDES significantly improved the tensile properties (1.1 MPa), ionic conductivity (2.1 S/m), and optical transparency (90%) of the PVA hydrogels. When the gel sensor was fixed to human skin, real-time monitoring of a variety of human activities could be implemented with accuracy and durability. Such a simple preparation method performed by combining a deep eutectic solvent with traditional hydrogels offers a new avenue to construct multifunctional conductive hydrogel sensors with excellent performance.

Fabrication of Multiphase Liquid Metal Composites Containing Gas and Solid Fillers: From Pastes to Foams

Gallium-based liquid metals (LMs) are suitable for many potential applications due to their unique combination of metallic and liquid properties. However, due to their high surface tension and low viscosity, LMs are challenging to apply to substrates in useful shapes, such as dots, wires, and films. These issues are mitigated by mixing the LMs in air with other materials, such as mixing with solid particles to form LM solid pastes or mixing with gases to form LM foams. Underlying these deceivingly simple mixing processes are complex and highly intertwined microscale mechanisms. Air microbubbles are inevitably incorporated while making LM pastes, making them partly foams. On the other hand, for foaming of the LM to occur, a critical volume content of solid particles must be internalized first. Consequently, both LM pastes and foams are multiphase composites containing solid and fluid microcomponents. Here, we systematically study the impact of the mixing procedure, solid particle size, and volume fraction (SiO2) on the air content of the multiphase LM composites. We demonstrate that decreasing the particle size and increasing their volume fraction substantially decrease the composite density (i.e., increases air entrapment). The foaming process can also be enhanced with the use of high-speed mechanical mixing, although leading to the formation of a more disordered internal structure. In contrast, manual mixing with larger microparticles can promote the formation of more paste-like composites with minimal air content. We explain the microscopic mechanisms underlying these trends by correlating macroscopic measurements with cross-sectional electron microscopy of the internal structure.

Manufacture and rheological behavior of all recycled PET/PP microfibrillar blends

AbstractFor several years, new plastic bottles made from opaque polyethylene terephtalate (PET) have been on the market. When their waste is mixed to those of recycled clear PET, the obtained material cannot be recycled anymore due to a loss of properties. Moreover, because of an important grade variety, the large number of additives used and poor homogeneity, the processing and recycling of opaque PET appears as a challenge. The way chosen to revalue this recycled opaque PET (r‐OPET) is its microfibrillation in a recycled polypropylene (rPP) matrix. The effects of the concentration of r‐OPET were studied by rheology, supported by scanning electron microscope images and related to the morphology of the mixture. It was demonstrated that (20/80)w r‐OPET/rPP blend was the best ratio to favor microfibrillation, as it offers the appropriate amount of solid filler to obtain a sea‐island morphology.Thereafter, the influence of the temperature of microfibrillation is presented. The thermomechanical curve of the (20/80)w r‐OPET/rPP blend suggests that microfibrillation should be more effective around the Tg of r‐OPET. The optimum temperature was found, where an improvement of rheological and mechanical properties is observed. A Cross model with yield stress is proposed to describe the rheological behavior of this material.

COMPOSITE MIXTURES BASED ON SYNTHETIC POLYMERS AND FILLERS AND EQUIPMENT FOR 3D PRINTING WITH THEM

The article states that the use of composite materials instead of traditional materials allows you to significantly reduce the weight of the product, while not changing the strength characteristics of this material. It was determined that polymer composite materials based on metal powders, high-strength organic (aramid) and carbon fiber fillers with a polymer matrix are promising for use as structural materials. Fillers are used to improve the operational properties of the composite material (strength, stiffness, heat resistance), give them various specific properties and reduce the cost. The classification of polymer composite materials by matrix and filler is presented. It is noted that the greatest variety of properties can be obtained using solid fillers of different nature (metals, ceramics, polymers) and structures. It has been established that both the type of filler and the shape and size of the particles are important when forming certain properties of polymer composite materials. It was determined that composite materials are used in additive technologies, in particular in 3D printing. Examples of the production of composite filaments by various companies, including various types of fillers, are given. The developed technology of printing with a mixture of polymer connector and filler using a 3D printer, which includes certain stages, is presented. Polymer materials and solid fillers of various nature were selected as the matrix for experimental research and their properties were described. The classification of equipment for forced mixing of materials is described. The developed extruder that prints with granules or composite mixtures of polymer materials and the 3D printer on which it is installed are presented. Composite mixtures for conducting experimental studies are given. The parameters of the printed samples to be examined are specified.

Preparation of Amphiphilic Solid Phase Extraction Material and Its Application in Aqueous Steroid Hormones Extraction

The steroid hormones have attracted increasing attentions in aquatic environment because of their endocrine disrupting effects at trace concentrations. In this work, amphiphilic solid phase extraction material of divinylbenzene-N-vinyl-2-pyrrolidinone polymer microsphere was synthesized by free radical polymerization. The adsorption of 4 steroid hormones in aqueous solution by prepared amphiphilic microsphere was determined by high-performance liquid chromatography-tandem mass spectrometry method. When methyl cellulose and sodium dodecyl sulfonate were used as dispersants, 2,2’-azobis(2-methylpropionitrile) was used as initiator, the amphiphilic microsphere was successfully prepared at 80 °C for 6 h. The amphiphilic microsphere has high specific surface area of 774 m2 g−1 with uniform particle size, which is comparable to the commercial solid phase extraction fillers. The amphiphilic microsphere has been successfully applied to the enrichment and detection of 4 steroid hormones (17α-hydroxyprogesterone, metandienone, norethindrone and boldenone) in natural water. The recoveries of 4 steroid hormones ranged from 83.7 % to 114 %, and the limit of detection were in the range of 0.70–13.5 ng L−1.

Experimental and numerical study on the thermocline behavior of packed-bed storage tank with sensible fillers

Packed-bed thermocline tank with sensible fillers is a cost-effective option for thermal energy storage (TES). In real charging and discharging, the thermocline stability is disturbed and thermocline expansion occurs due to various factors, leading to the decreased global performances of storage tank. The purpose of this work is to experimentally and numerically study the impact of inlet configuration and insulation on the thermocline expansion in a lab-scale tank under various operating parameters. Firstly, a DC-3P model considering the wall effect and heat loss is developed and validated by experimental results, capable of precisely predicting the performance of storage tank under the tested conditions. Especially, the temperature difference between the fluid and solid filler center is detected both in experiments and in modeling, indicating the existence of temperature gradient inside large solid particles. Results also show that the injecting flow causes the radial temperature non-uniformity and thermocline expansion at the near-entrance region of the tank, but its effect on the global performance of the storage tank is rather limited. Good insulation of the tank could reduce the thermocline thickness by about 20%, and increase the energy efficiency and the capacity ratio by 5–7% and 3–5%, respectively.

Evaluating the effect of solid lubricant inclusion on the friction and wear properties of Laser Sintered Polyamide-12 components

The processing of Polyamide-12 (PA12) by Laser Sintering is one of the most well-established Additive Manufacturing (AM) processes for producing functional components for end-use applications. However, its further adoption within industry remains hindered by an incomplete understanding of resultant part quality and the impact this has on component wear. The scope of this research was to investigate the dry sliding behaviour of Laser Sintered Polyamide-12, as well as evaluate whether the inclusion of solid lubricant fillers effect the friction and wear properties of parts produced. Polytetrafluoroethylene (PTFE), Graphite and Molybdenum disulphide (MoS2) were added to Polyamide-12 powder in 1 : 100 mass ratios, respectively, to create three different polymeric composites. Mechanical blending and Laser Sintering then ensued; the latter was performed using identical processing parameters throughout. Tribological performance was evaluated by ball-on-flat uni-directional wear testing. Tensile testing was also carried out to help elucidate what wear mechanisms were active during sliding, as well as identify whether solid lubricant inclusion impacted mechanical performance. Results showed that in all instances solid lubricant inclusion significantly influenced the friction and wear properties of resultant composites, without compromising their mechanical performance when compared with neat-PA12. More specifically, it was demonstrated that the individual additions of PTFE and MoS2 could reduce the coefficient of friction and specific wear rate of Laser Sintered PA12 components by as much as 50% and 78%, respectively.

Study of a complex of functional properties of phenolic composites using a dispersed fibrous filler

The article presents the results of studies of basic physical, mechanical, tribological and electrotechnical properties of composite thermosetting polymeric materials having optimal composition based on solid resin phenol formaldehyde resins and dispersed fibrous filler obtained by mechanical recycling of cellulose fibrous waste products of pulp and paper industry. Physical and mechanical properties (density, tensile and bending strengths, impact strength, degree of absorption for moisture and mineral oil), tribological indicators (wear intensity and stability, friction coefficients in the contact zone of a friction pair under various staticdynamic and thermal loads), electrical characteristics (volume resistivity, electrical strength) and a brief analysis of structural changes in the studied phenolic composites, as well as recommendations for their use as technical products for machine-building and general electrical purposes are presented.

Oral Region Myomodulation and Skin Rejuvenation With Polydioxanone Threads and Hyaluronic Acid Filler: Cross-Filler Technique

The facial aging process is progressive, and rejuvenation of the oral region is challenging, as the skin alterations also reflect the changes in the fat, muscles, ligaments, and bone. Therefore, the procedures for improving this region must be combined to optimize the result. The use of polydioxanone (PDO) threads has been increasing in cosmetic dermatology in the last few years. Different types of threads, barbed, molded, non-barbed, straight, screwed, filler, etc., are available in the market bringing new options for treatment. Here, we want to present a new technique using a particular type of PDO thread, called solid filler thread, which was developed to fill folds in the face, replacing hyaluronic acid (HA) gel in some cases. Based on its purpose, it could also act as HA filler for myomodulation with the advantage of not promoting volume next to modiolus. In our technique, we associated HA filler gel in the areas where volume was desired, such as lips and mental area. We will report some cases to illustrate our technique and show the improvement in static and dynamic wrinkles, restructuring the oral region.