Acrylic Fibers Research Articles

Structure-property relationship of carbonized needlepunched nonwovens for electromagnetic interference shielding and ohmic heating applications

The structure-property relationship of acrylic and Kevlar fibre derived activated carbon fabrics was investigated for electromagnetic interference shielding and joule heating applications. The single stage carbonization and physical activation of acrylic and Kevlar needlepunched nonwoven fabric was carried out under the modified atmosphere of charcoal layer and nitrogen gas to have gradual reaction with atmospheric air. The effect of 800 °C, 900 °C and 1000 °C carbonization temperature on structural and functional properties was studied. The acrylic-derived activated carbon fabric was found to provide higher carbon yield, less dusting tendency, better mechanical and electrical properties; however poor flexibility and shrinkage properties as compared to Kevlar derived activated carbon fabrics. The formation of more micropores, higher graphitic structure, higher degree of crystallinity, and large surface area was observed in case of both the activated carbon fabrics with rise in carbonization temperature. Furthermore, the activated carbon fabrics derived at 1000 °C exhibited greater electromagnetic interference shielding in high as well as low frequency regions. Lastly, the ohmic heating of carbonized Kevlar fabric showed rapid heating, high electric heating efficiency and faster cooling performance but at increased voltage of 5 V than 3 V of carbonized acrylic fabric.

Microplastics in Ship Sewage and Solutions to Limit Their Spread: A Case Study

The case study presented in the paper is the first in the field to find microplastic (MP) particles in both grey water (GW) and post-treatment sewage (TS) samples, which can also be legally discharged into specially protected areas. Compiling a data set of 50 water samples collected from the GW and TS samples of 5 transport ships involved in the case study, we show that the mean number of separated microparticles in the GW samples n = 72 particles per litre, and in the TS samples n = 51 particles per litre. Of the 614 separated particles, the most common were fibres n = 285 (46.4%), followed by other (various) hard particles n = 226 (36.8%) and soft particles n = 104 (16.8%). Attenuated total reflectance Fourier transform infrared spectroscopy (ATR FT-IR) identification was mainly in the form polyethylene (PE), polypropylene (PP) (solid particles and films), polyesters, polyamides, and acrylic fibres. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) analysis revealed ecotoxic chemical elements on the surface of these particles. Our results show that the sewage treatment facilities installed on ships need to be improved, and we developed a solution for this. The findings of the case study certainly deserve further attention and serve as an impetus for research on the improvement of ship wastewater treatment facilities.

Metric entropy and digital image correlation in deformation dynamics analysis of fibre glass reinforced composite under uniaxial tension

This paper proposes a combined method for the mechanical properties assessment of composite materials based on the analysis of the internal dynamics of raw data from uniaxial tensile tests. Determination of the Kolmogorov-Sinai (K-S) metric entropy from the recorded data enables to find the tensile strength of materials. The correctness of the methodology proposed was verified by the full filed DIC measurements. Therefore, the main aim of this research was to apply independent measurement tools in the analysis of the non-linear dynamics supported by their mutual validation. The experimental program carried out on the glass fibre-based thermoplastic Elium acrylic composite and E752 Carbon Fiber Reinforced Epoxy (CFRE) composite confirmed the high suitability of the presented methodology in ultimate tensile stress identification, and thus, its great applicability potential in many aspects of the contemporary engineering.

Synergistic electronic and geometric effects of Au/CeO2 catalyst for oxidative esterification of methacrolein

AbstractMethyl methacrylate (MMA) is an important monomer for the production of acrylic plastics and polymer dispersions. In this study, we demonstrate a strategy to synergize the electronic and geometric effects of the Au/CeO2 catalyst, achieving three orders of magnitude improvement in reaction rate for the oxidative esterification of methacrolein to MMA. The electronic properties of Au in terms of the valence electron population of 5d states are decoupled from the redox ability and acid–base properties of catalyst support as the main cause for the significant increase in the specific activity of the active site. Moreover, the Au edge site is identified as the main active site for this reaction, whose number reaches the maximum for the 1.6 nm‐sized Au particles. Hence, the synergism between the electronic (lower valence electron population of 5d states) and geometric (more edge active sites) promotions of the Au‐10/CeO2 catalyst contributes to the highest catalytic activity.

Physical and Chemical Regularities of Phosphorus and Beryllium Recovery by the Sorbents Based on Acrylic Fiber Impregnated by Iron Hydroxide (III)

The paper investigates the physicochemical regularities (kinetics and isotherm) of phosphorus and beryllium recovery by sorbents based on polyacrylonitrile (PAN) fiber and Fe(OH)3 obtained by various methods: PAN or pre-hydrolyzed PAN with precipitation of FeCl3 with ammonia, using ready-made or electrochemically generated Na2FeO4, pre-hydrolyzed PAN treated with an alkaline solution of Na2FeO4, as well as their comparison with granular aluminum oxide. The Langmuir, Freudlich and Dubinin–Radushkevich models show high performance of materials for sorption of stable P and Be used as tracers for the release of 7Be, 32P, and 33P from seawater. The obtained kinetic data are processed using kinetic models of intraparticle diffusion and the pseudo-first-order, pseudo-second-order, and Elovich models. Optimal conditions for obtaining sorbents are established, namely, the effect of NaOH concentration at the stages of preparation on the properties of sorbents based on the PAN fiber and Fe(OH)3 obtained by various methods.

Segregation of effect between granules and flocs in PN/A system treating acrylic fiber wastewater: Performance and mechanism.

Nitrogen removal of petrochemical wastewater through partial nitritation/anammox (PN/A) is appealing, but its feasibility and stability under toxic inhibition remain unclear. This study started a PN/A granular sludge system in a membrane bioreactor and fed it with diluted acrylic fiber wastewater. During long-term operation, the nitritation and anammox performance remained stable at a 30% volume ratio, and declined with increasing volume ratio, resulting in deteriorated nitrogen removal. Meanwhile, the short-term inhibition batch tests further showed that ammonia oxidation bacteria (AOB) in the flocs were suppressed while anammox bacteria (AnAOB) in the granules were not affected. Further analysis indicated suppression of AnAOB over the long-term operation, which was mainly caused by the disintegration of granules as demonstrated by sludge morphology. This selective inhibition is associated with variational sludge morphology, and the distribution of functional bacteria plays an important role in the feasibility and stability of PN/A treating acrylic fiber wastewater. As above, this study demonstrated the feasibility of PN/A for acrylic fiber wastewater treatment, but wastewater dilution or pre-treatment is still required for efficient nitrogen removal.

High-resolution fiber imaging for pulsed power experiments.

This work presents a novel approach for imaging the visible emissions from plasmas in pulsed power experiments using high-resolution plastic optical fibers. The diagnostic consists of a 2mm diameter core commercial cable constructed of 13000 individual acrylic fibers. The fibers are fused together to create a single high-resolution bundle. Different designs were investigated to cover a wide range of resolutions and fields of view (3-700 µm and 0.05-45mm, respectively). The system was tested on the 1-MA Mykonos accelerator at Sandia National Laboratories and successfully imaged visible emission from a hybrid x-pinch target. Diagnostic development and preliminary results are presented.

Mechanical Performance and Durability of Date Palm Fibers Repair Mortar

Background: Concrete is the most widely used material in the world after water. However, concrete could be damaged under aggressive environments and many concrete structures require repair and frequent maintenance. Readymade mortars with and without synthetic fibers such as polypropylene and acrylic are often used as repair mortars. The partial replacement of cement by supplementary cementitious materials and the use of alternative fibers such as natural and agro-waste fibers could reduce the environmental impact of readymade mortars. Methods: This paper presents a comparative study between the performance of laboratory made and ready-made repair mortars. The laboratory repair mortars were based on date palm fibers and local mineral additions (slag and natural pozzolan). The volume ratio of date palm fibers addition was 0.75% and mineral additions content were fixed at 15% as cement replacement. Compressive strength, flexural strength, shrinkage and the bond strength by slant shear test and tensile strength of concrete by the pull-off method were investigated. The durability of the mortar was evaluated by water capillary absorption. Results: The results indicated that the addition of natural fibers and the substitution of cement by 15% of mineral additions improves the flexural strength but reduces the compressive strength of the fiber-reinforced repair mortar. The lowest values of total shrinkage, water capillary absorption and sorptivity were observed for repair mortars based on acrylic fibers compared to repair mortars with natural vegetables fibers. Conclusion: The mechanical and durability performances of laboratory made repair mortars were comparable to those of readymade mortars.

Circular adsorptive utilization of benzalkonium chloride via construction of ionic microenvironment in dopamine quinone-functionalized acrylic fiber surface

A novel dopamine quinone-functionalized acrylic fiber (PANdpqF) was successfully synthesized, which adsorbed the disinfectant dodecyl dimethyl benzyl ammonium chloride (DDBAC) to in-situ construct a highly efficient catalyst (DDBAC@PANdpqF) for the cyclization of CO2 with epoxide. The successful preparation of PANdpqF was proved by 13C Cross Polarization-Magic Angle Spinning nuclear magnetic resonance, X-ray photoelectron spectroscopy, Fourier transform infrared, and scanning electron microscopy. High adsorption capacity of DDBAC on PANdpqF has been demonstrated by ultraviolet analysis, and the theoretical maximum adsorption capacity was calculated as 666.67 mg/g. Based on comprehensive analysis, the corresponding adsorption mechanism is proposed in which chloride ion of DDBAC is added to o-quinone moiety through Michael addition, followed by the formation of phenoxy and quaternary ammonium ion pair. DDBAC@PANdpqF was well applicable to catalyze the cyclization of CO2, and the yield could reach 93.7% even with a low catalyst loading. The possible cooperatively catalytic mechanism was proposed correspondingly, in which phenolic hydroxyl helps to activate CO2 and epoxide, phenoxy anion attacks CO2 as a nucleophile, and quaternary ammonium cation stabilizes the anionic intermediates. Overall, the functionalized acrylic fiber adsorbed environmentally harmful disinfectant DDBAC to furnish a highly active catalyst for the transformation of greenhouse gas CO2 into useful carbonates, which provides a new method for advanced environmental pollution control.

Exploration of the Fluorescence Property of Acrylic Fibers Dyed with the Residues Extract of Juglans regia Barks

This study aims to check the fluorescence property of acrylic fabrics dyed with Juglans regia bark extract. Fluorescence measurements have been developed on the aqueous extract and acrylic samples. The extraction process was assisted by a microwave with the following conditions: a concentration of 5 g·L−1, a power of 850, a pH of 5 and an extraction duration of 4 min. Afterwards, the dyeing quality was assessed by measuring the color strength (K/S) and the photoluminescence intensity (PL) of acrylic fibers dyed at 350 W for 3 min, with the extract already prepared. The effect of certain factors (pH, power, concentration and duration of dyeing) on the dyeing process was also investigated. Subsequently, this process was optimized thanks to the surface response method in order to maximize the photoluminescence intensity of dyed acrylic fibers. Best dyeing properties were achieved at 500 W, pH 2 for 4 min. The results showed good washing fastness and acceptable light fastness.

Fenton Process for Treating Acrylic Manufacturing Wastewater: Parameter Optimization, Performance Evaluation, Degradation Mechanism

Acrylic manufacturing wastewater is characterized by high toxicity, poor biodegradability, high chemical oxygen demand (COD) and ammonia nitrogen. Herein, we exploited traditional Fenton technology to treat acrylic fiber manufacturing wastewater. The impacts of key operating variables including the initial concentration of H2O2 (CH2O2), the initial concentration of Fe2+ (DFe2+), and solution pH (pH) on the COD removal rate (RCOD) were explored and the treatment process was optimized by Response Surface Methodology (RSM). The results indicated that the optimum parameters are determined as pH 3.0, 7.44 mmol/L of Fe2+ and 60.90 mmol/L of H2O2 during Fenton process. For the actual acrylic manufacturing wastewater treatment shows that the removal rates for COD, TOC, NH4+-N and TN are 61.45%~66.51%, 67.82%~70.99%, 55.67%~60.97% and 56.45%~61.03%, respectively. It can meet the textile dyeing and finishing industry water pollutant discharge standard (GB4287-2012). During the Fenton reaction, the effective degradation and removal of organic matter is mainly achieved by HO• oxidation, supplemented by flocculation and sedimentation of Fe3+ complexes. This study will provide useful implications in the process parameters for the practical application of Fenton method in acrylic acid production wastewater.

A rapid method for determining low concentrations of 210Pb in drinking water using MnO2 fibers

A rapid method for determining low activity concentrations of 210Pb in drinking water was developed and tested. The method consists of a few stages for sample preparation that involve passing 12 L of water through a column with acrylic fibers implanted with MnO2 (used to adsorb 210Pb). The MnO2 fibers are oven-dried, compressed and measured by a broad-energy germanium detector used to quantify 210Pb via its characteristic 46.5 keV γ-ray. The time taken for sample preparation is approximately 4 h and recovery factors for lead in tap water of 87 ± 3% were achieved. After a measurement duration of 4 h, the minimum detectable activity concentration reaches 0.02 Bq/L for 210Pb, being well below the respective limit for drinking water in Israel (0.2 Bq/L) as well as the value recommended by the World Health Organization (0.1 Bq/L). Furthermore, a measurement duration of 48 h provides a minimum detectable activity concentration of ∼0.006 Bq/L, which is similar in magnitude to other, well-established methods that rely on lengthy and rather complex procedures. Thus, the combination of MnO2 fibers and gamma-ray spectrometry may be attractive for routine use by analytical laboratories that monitor radioactivity in drinking water.

Thermo-physiological Comfort Performance of Recycled Plain Knitted Fabrics Produced from Acrylic Waste Fiber with the Effects of Incorporated Covered and PBT Elastic Yarns

Thermo-physiological Comfort Performance of Recycled Plain Knitted Fabrics Produced from Acrylic Waste Fiber with the Effects of Incorporated Covered and PBT Elastic Yarns

Flexural strength of heat polymerized acrylic resin repaired with different reinforcing materials

Purpose: Heat cure methyl methacrylate has been the denture base material of choice for the fabrication of conventional complete dentures and transitional removable partial dentures. One of the factors that cause fracture is considered to be low resistance to impact, flexural or fatigue. However, dentures repaired with auto-polymerizing acrylic resin alone often experience a re-fracture at the repaired site. This study aimed to evaluate flexural strength of heat polymerized acrylic resin repaired with different reinforcing materials.
 Methods: 48 samples were prepared and divided into four groups. 12 samples were considered as controls, and 36 were divided into 3 experimental groups. The samples were sectioned into two halves from the middle, and were then repaired with rapid repair material, and reinforcing material. Each group was divided into 4 subgroups: unreinforced, reinforced with metal wire, metal mesh, and glass fiber. All specimens were subjected to a 3-point bending test, and the flexural strength was calculated. Results: all the reinforcement groups namely Stainless steel wire, metal mesh and glass fiber improves flexural strength of heat cured acrylic resin samples and glass fiber reinforced samples had the greatest flexural strength when compared with all other groups.

The Sorbents Based on Acrylic Fiber Impregnated by Iron Hydroxide (III): Production Methods, Properties, Application in Oceanographic Research

Sorbents based on Fe(OH)3 and aluminum oxide are widely used in oceanology for the recovery of cosmogenic radionuclides 7Be, 32Si, 32P, and 33P from the seawater. It is also possible to use them for the recovery of the natural radionuclides 210Pb, 234Th. A comparative study of the sorbents based on Fe(OH)3 and acrylic fiber obtained through various impregnation methods was carried out, and their comparison with granulated aluminum oxide. The possibility of extracting trace amounts of phosphorus and beryllium under laboratory and field conditions with these sorbents was studied. The sorption of 7Be, 210Pb, and 234Th on the natural content by the two-column method was investigated. It is shown that fiber samples obtained by oxidation with sodium ferrate and the “classical” method have the highest sorption characteristics.

COMPARATIVE EVALUATION OF ADHESIVE ABILITY OF MICROORGANISMS TO THERMOPLASTIC AND ACRYLIC BASE POLYMERS FOR REMOVABLE DENTAL PROSTHESES POLISHED WITH DIFFERENT PASTES

The ability of microorganisms to penetrate into the thickness of the material directly depends on the surface quality and structure of the material. In order to counteract the adhesion and colonization of microorganisms, it is essential to obtain the smoothest possible surface of the prosthetic structure with low values of roughness and free surface energy. Non-compliance with the technique of manufacturing removable orthopedic structures with the formation of roughness, pores, and lack of proper care for the prosthesis promotes the adhesion of microorganisms and their penetration into the base of the dental prosthesis.
 The aim of the study. Comparative evaluation of the adhesion of test microorganisms (Staphylococcus aureus АТCC 6538, Escherichia coli ATCC 25922, Candida albicans АТСС 10231, Enterococcus faecalis IMB В-7497) on the surfaces of samples of acrylic and thermoplastic polymers treated with different polishing pastes.
 Materials and methods. Four types of samples are used in the study to assess the adhesive ability of microorganisms from thermoplastic material "Vertex ™ ThermoSens" and polymethylacrylate copolymer "Villacryl H Plus" which are treated with polishing paste — "Blue Shine." As well as from the thermoplastic material "Vertex ™ ThermoSens," from polymethylacrylate copolymer "Villacryl H Plus" which are treated with universal polishing paste "Vertex ™ ThermoGloss."
 A suspension of test strains was prepared according to the optical turbidity standard at the rate of 1x109 CFU / cm3 to determine the adhesive ability of polymer samples from daily crops grown on TCA (for bacteria) for 24 hours and 48 hours for Candida albicans grown on Saburo agar. The test samples were then placed in sterile containers; 10 ml of test culture suspension was added to each of them and cultured at 37°C with appropriate test strains of microorganisms. The adhesion of microorganisms to samples of base polymeric materials treated with various polishing pastes was evaluated.
 Results. An in vitro study shows that thermoplastic materials, in contrast to the acrylic plastics used in the experiment, have less ability to colonize the pathogenic microflora on their surface. Each base material, depending on the physicochemical parameters, has a distinctive qualitative and quantitative profile of adhesion of microbial flora. The obtained data allow to conclude that samples of polymeric materials for prosthesis bases differ significantly in the degree of adhesion of bacteria and fungi of the genus Candida, which depends on the surface structure of the material, polishing method, choice of polishing pastes, which accordingly determines differences in colonization resistance to the formation of microbial biofilms when using the polymer in clinical conditions.
 Conclusions. Consequently, the study results are important for critical evaluation of the quality of polishing thermoplastic and acrylic materials for the bases of removable dentures in terms of contamination on their surface of pathogenic microorganisms. The degree of contamination of acrylic and thermoplastic polymeric materials used for the manufacture of removable dentures will depend not only on their structural integrity and timing but also on the body's reaction to them, the development of inflammation, and allergic reactions.

Development of a digital fabrication device for the manufacture of removable dentures

BACKGROUND: Digital technologies such as those used to manufacture complete removable dentures have become widely popular in the field of dentistry. The fabrication of an accurate, monolithic removable denture where the teeth and base are made using subtractive or additive technologies is crucial.
 AIM: The aim of the current study was to develop a device that permits manufacture of removable dentures using digital technologies.
 MATERIAL AND METHODS: The article describes modern methods of manufacturing complete removable dentures.
 RESULTS: With the help of digital technologies, it was possible to obtain a monolithic prosthesis made of plastic, eliminating inaccuracies in the positioning of teeth during placement in the basis of the prosthesis, as well as to connect the basis of the prosthesis and teeth using acrylic plastic. Additionally, a brief description of the basic tools and materials necessary for this technique have also been provided.
 CONCLUSION: The advantages of digitally manufacturing complete removable dentures include high accuracy, absence of overbite, high speed, and minimal shrinkage. These benefits allow us to conclude that the use of digital protocols for the manufacture of complete removable dentures is essential in order to achieve favorable treatment outcomes that meet the expectations of the doctor and the needs of the patient.

On the issue of hygienic maintenance of post-resection maxillary obturator prostheses (literature review)

Based on literature data, this article reviews a range of problems associated with hygienic care after obturation prostheses and the oral cavity after combined treatment of malignant neoplasms. At the present time, replacing prosthetic care after maxillary resection due to malignant neoplasms using obturator prostheses is the main method for rehabilitation of oncological patients. Such methods as dental prosthetic care based on dental implants and removable dentures for elimination of partial and complete edentulism is impossible in such conditions. A defect in the maxilla, an oronasal fistula, post-operative and post-radiation jaw contracture as well as hyposalivation, impair the hygiene of the oral cavity. Acrylic plastics used for production of obturator prostheses have such substantial flaws leading to development of inflammation and progression of atrophy in the supporting tissues of the basal seat. This reduces short-term and long-term efficacy of orthopaedic dental rehabilitation procedures after replacing dental prosthetics. A conclusion has been drawn on the necessity of development and practical introduction of a special complex of dental hygienic procedures — professional and individual — adapted for oncological patients that would be implemented within the framework of dynamic dispensary observation in the setting of a dental polyclinic.

Mode-dependent dye absorption in phthalocyanine-doped acrylic optical fiber

Phthalocyanine has attractive features as a dopant for plastic optical fibers. Its planar molecular structure and red absorption band are suitable for the design of fiber-optic strain sensors that use the dynamic orientation of dye induced by the deformation of the host matrix. The guidelines to achieve a phthalocyanine-doped fiber with a ruled dispersing manner were investigated. A synthesized fiber using phthalocyanine decorated with tertiary butyl groups showed mode-dependent absorption, which suggested gradual dye distribution in the core radial direction.

Sequestering Rare Earth Elements and Precious Metals from Seawater Using a Highly Efficient Polymer Adsorbent Derived from Acrylic Fiber

An amidoxime and carboxylate containing polymer adsorbent derived from acrylic fiber has shown extremely high efficiencies for extracting critical materials and precious metals from seawater. Among 50 extractable elements, the lanthanides, cobalt, and palladium were ranked near the top with KD values in the order of 107, about an order of magnitude higher than that of uranium. The KD value of the lanthanides increased linearly with the atomic number indicating charge density is a factor controlling trivalent lanthanide extractability in seawater. The data given in this report provides crucial information regarding the strategies of ocean mining of critical materials and precious metals.