Characteristics of Coaxial Dielectric Barrier Discharge at an Atmospheric Pressure with a Swirling Gas Argon/Oxygen Mixture for the Surface Modification of Polyester Fiber Cord

Abstract A newly developed coaxial dielectric barrier discharge reactor with a length of 1000 mm at an atmospheric pressure was used for plasma treatment of polyester fiber cord in a roll-to-roll manner. In this reactor, swirling mixture gases of oxygen of about 1% and argon with a flow rate of 1.5 L/rain to 2.7 L/min ensured the gas usage sparing, discharge uniformity and efficient fiber surface modification. The water contact angle and surface morphology of the treated fiber were measured. The results show that the surface oxygenation is mainly responsible for the wettability improvement of the fiber cord when passing through the plasma zone at a linear speed of 3 m/min to 8 m/rain. The specimens of modified-polyester fiber reinforced rubber composite were also prepared for the interracial shear strength tests. Furthermore, the effect of adding oxygen into argon discharge on the fiber surface oxidation was correlated with optical emission spectroscopy. Finally, the effect of adding oxygen into argon discharge on the kinetic processes of the active species generation were also analyzed.

Decorative Wood Fiber/High-Density Polyethylene Composite with Canvas or Polyester Fabric

Wood-plastic composite is an environmentally friendly material,due to its use of recycled thermoplastics and plant fibers.However,its surface lacks attractive aesthetic qualities.In this paper,a method of decorating wood fiber/high-density polyethylene(WF/HDPE)without adding adhesive was explored.Canvas or polyester fabrics were selected as the surface decoration materials.The influence of hot-pressing temperature and WF/HDPE ratio on the adhesion was studied.The surface bonding strength,water resistance,and surface color were evaluated,and observation within the infrared spectrum and under scanning electron microscopy was used to analyze the bonding process.The results showed that the fabric and WF/HDPE substrate could be closely laminated together depending on the HDPE layer accumulated on the WF/HDPE surface.The molten HDPE matrix penetrates canvas more easily than polyester fabric,and the canvasveneered composite shows a greater bonding strength than does the polyester fabric-veneered composite.A higher proportion of the thermoplastic component in the substrate improved the bonding.When the hot-pressing temperature exceeded 160°C,the fabric-veneered WF/HDPE panels had greater water resistance,although the canvas fabric changed more obviously in terms of fiber shape and color,compared with the polyester fabric.For the canvas fabric,140°C–160°C was a suitable hot-pressing temperature,whereas 160°C–180°C was more suitable for polyester fabric.The proportion of the thermoplastic component in the composite should be not less than 30%to achieve adequate bonding strength.

Preparation of Core/Shell Electrically Conductive Fibers by Efficient Coating Carbon Nanotubes on Polyester

Conducting fibers with improved properties and functionalities are needed for diverse applications.Here we report the fabrica-tion of core/shell conductive Dacron fibers by dip-coating method through originating from multi-walled carbon nanotubes(MWCNTs)coated on polyester fibers.The annealing process was conducted to enhance interaction between the conductive shell and polyester core as well as within the MWCNTs network.The properties of two kinds of MWCNTs dispersions and the electrical properties of conductive fibers were studied,respectively.The results show that both MWCNTs-polyurethane resin(MWCNTs-WPU)dispersion and MWCNTs-acrylic resin(MWCNTs-PAA)dispersion present a typical characteristic of pseudo-plastic fluid and an excellent wetting ability to polyester fibers.The ultimate tensile stress and elongation at break for the MWCNTs-PAA coated fiber are 261 MPa and 25.43%.The ultimate tensile stress and the elongation at break are both increasing with the increasing of MWCNTs contents,due to the strong interface bonding ability between the conduc-tive shell and polyester core and strengthen the MWCNTs network.The electrical resistance of the obtained fibers can be controlled in the range from 732 to 30Ω/cm by changing MWCNTs content,dipping times and annealing temperature.It was found that it is able to light a LED.All results suggest that the conductive fibers embody a good synergy effect of carbon nanotubes and polymers.Therefore,the fabricated conductive fibers have a widely prospect for being applied in the field of flexible electronics.

Laboratory Evaluation of Fiber-Modified Asphalt Mixtures Incorporating Steel Slag Aggregates

Vigorous and continued efforts by researchers and engineers have contributed towards maintaining environmental sustainability through the utilization of waste materials in civil engineering applications as an alternative to natural sources.In this study,granite aggregates in asphaltic mixes were replaced by electric arc furnace(EAF)steel slag aggregates with different proportions to identify the best combination in terms of superior performance.Asphalt mixtures showing the best performance were further reinforced with polyvinyl alcohol(PVA),acrylic,and polyester fibers at the dosages of 0.05%,0.15%,and 0.3%by weight of the aggregates.The performance tests of this study were resilient modulus,moisture susceptibility,and indirect tensile fatigue cracking test.The findings of this study revealed that the asphalt mixtures containing coarse steel slag aggregate exhibited the best performance in comparison with the other substitutions.Moreover,the reinforced asphalt mixtures with synthetic fibers at the content of 0.05%exhibited an almost comparable performance to the unreinforced asphalt mixtures.Modifying the asphalt mixtures with PVA,acrylic,and polyester fibers at the proportion of 0.15%have improved the fatigue cracking resistance by 41.13%,29.87%,and 18.97%,respectively.Also,the fiber-modified asphalt mixtures with PVA,acrylic,and polyester have enhanced the fatigue cracking resistance by about 57%,44%,and 39%,respectively.The results of the resilient modulus demonstrated that as the fiber content increase,the resilient modulus of the reinforced asphalt mixtures decreases.Therefore,introducing synthetic fibers at the content of 0.3%has slightly decreased the resilient modulus in comparison with unreinforced mixtures.On the other hand,the results of the mechanisticempirical pavement design showed that the reinforced asphalt mixes with a high content of synthetic fibers have shown lower service life than the control mixes due to the low resilient modulus.On the contrary,based on the laboratory results,the asphalt mixes incorporating PVA,acrylic,and polyester fibers at the proportion of 0.15%have shown the potential to reduce the thickness of the asphalt layer by about 14.9%,11.80%,and 8.70%,respectively.

Analysis of the Composition and Physical and Mechanical Properties of Raw Materials for Thermal Insulation Fabrics

In this article, winter clothes, bedding, pillows, mattresses are produced in the Republic of Uzbekistan and used in the export products of foreign countries in domestic market shopping centers;existing nonwoven fabric samples were used as toys, children’s clothing as a heat retainer, a space-filler was selected on the basis of marketing survey analysis. Chemical bonding, processing technology, methods, linear density, thickness, air permeability, hygroscopicity, heat storage and heat transfer properties of the samples were analyzed experimentally based on the preparation methods, the fiber content was compared with the standard technology. The advantages and disadvantages of the samples were studied and recommendations for use in sewing according to consumer requirements were given.

Fabrication and Properties of Graphene Oxide/Sulfonated Polyethersulfone Layer-by-layer Assembled Polyester Fiber Composite Proton Exchange Membranes

Using the hydrogen-bonding interaction between graphene oxide（GO） and sulfonated polyethersulfone （SPES）, we constructed the multilayer structure of GO and SPES on the polyester tiber mats via layer-by-layer self-assembly. In each self-assembled layer, sulfonic acid groups are arranged along the a^s of fiber, which provides the long-range proton transmission channels, promoting the rapidly proton conduction. The performances of the composite membranes based on SPES and multilayer assembled polyester fiber mats were studied. The results show that the proton conductivity of composite membranes increases with the increasing assembly layers. At the same time, the mechanical properties and methanol-resistance of the composite membranes were obviously improved.

Bioreduction of nitrate in groundwater using a pilot-scale hydrogen-based membrane biofilm reactor

A long-term pilot-scale H_(2)-based membrane biofilm reactor(MBfR)was tested for removal of nitrate from actual groundwater.A key feature of this secondgeneration pilot MBfR is that it employed lower cost polyester hollow fibers and still achieved high loading rate.The steady-state maximum nitrate surface loading at which the effluent nitrate and nitrite concentrations were below the Maximum Contaminant Level(MCL)was at least 5.9 g·N·(m^(2)·d)^(–1),which corresponds to a maximum volumetric loading of at least 7.7 kg·N·(m^(3)·d)^(–1).The steady-state maximum nitrate surface area loading was higher than the highest nitrate surface loading reported in the firstgeneration MBfRs using composite fibers(2.6 g·N·(m^(2)·d)^(–1)).This work also evaluated the H_(2)-utilization efficiency in MBfR.The measured H_(2)supply rate was only slightly higher than the stoichiometric H_(2)-utilization rate.Thus,H_(2)utilization was controlled by diffusion and was close to 100%efficiency,as long as biofilm accumulated on the polyester-fiber surface and the fibers had no leaks.