International Journal of Polymer Analysis and Characterization最新文献

Influence of concentration of introduction the different industrial organic additives into the epoxy resin on wetting contact angle is studied experimentally. Epoxy resin ED-20 is modified with small concentrations of polydimethyl siloxane, OH-polymer silicone rubber, monoglycidyl ether of butyl cellosolve (Laproxide 301B), tris(2-chloroethyl) phosphate. The importance of these studies is related to the need to improve the adhesive properties of repair compounds based on epoxy resin, which are associated with the value of the contact angle. The contact angle of the resin drop is measured for glass, metal, asbestos cement, and concrete surfaces. The effect of the mass fraction of additives on the contact angle is more pronounced on smooth surfaces of dense materials, and less pronounced on rough surfaces of porous materials. It is observed that all dependences of contact angle on the mass fraction of additives in the range of 0.5–2% wt are linear. The linear equation $\theta =s\cdot c+{\theta }_0$ describing the contact angle θ dependence on the mass fraction c of additives, which sufficiently fitting the experimental data with calculated coefficients s and θ₀, is found.

We have developed conductive, lightweight, and porous composite of polyvinylidene difluoride by blending with synthesized conjugated terpolymer and graphene for conductive polymer composite applications. The new conjugated terpolymer designated as PEPy-TP is synthesized from 3,4-ethylenedioxythiophene, 1-pyrenecarboxzaldehyde, and heptaldehyde through friedel craft reaction. The synthesized terpolymer PEPy-TP have been blended with polyvinylidene difluoride and graphene nanosheets to form porous composite and has been characterized using XRD, TGA, TG-DSC, DTA, DTG, SEM, EDX, and Dielectric spectroscopy. The porous composite is comprised of varying weight percentages of (1, 3, and 5%) of GNS and 10 wt% PEPy-TP in PVDF. The thermal studies on the porous composites indicated that the decomposition occurred at a temperature around 270 and 470 °C corresponds to the PEPy-TP and PVDF/PEPy-TP/GNS (1, 3, and 5%), respectively. The EDX spectrum of neat PEPy-TP polymer and their porous composites of PVDF/PEPy-TP/GNS (1, 3, and 5%) result clearly shows the presence of all elements, such as C, O, S, and F with an atomic weight percentage also. The PVDF/PEPy-TP/5% GNS porous composites having a tremendous electrical conductivity and the dielectric constant value is 56 at 1 MHz and their conductivity of this polymer porous composites value is determined to be 4.9 × 10⁻⁶ S/cm at 100 kHz, respectively.

This paper aimed at the problem of uneven heating of ultra-high molecular weight polyethylene (UHMWPE) bearing in the process of UHMWPE was made into water-lubricated bearing, and have used ICEPAK software to study the temperature distribution of the UHMWPE during hot pressing. Research indicated that hot pressing UHMWPE was an unsteady heat transfer in the process of heating and holding. Air convection had little effect on the overall process. During processing, the slow heating method to process smaller UHMWPE water-lubricated bearing could effectively reduce the temperature difference. It made the inner heating of UHMWPE uniform and equated to the temperature of the shaft sleeve. This research can provide data support for temperature control and process optimization for the UHMWPE-based water-lubricated bearing hot pressing process.

The improvement of adsorbent materials with specific characteristics is very important in different environmental applications such as the removal of undesirable elements (wastewater treatment) or separation of elements or radionuclides and remediation of organic pollutants from their solutions. Herein, a cross-linked poly(acrylic acid-dimethyl aminoethyl methacrylate) was prepared by a copolymerization technique in the existence of N, Ǹ-methylene bis-acrylamide as a cross-linked agent using gamma irradiation (γ-rays) to induce the polymeric reaction at a minimum radiation dose of 30kGy. The optimization of polymer preparation was done using different parameters such as radiation dose, cross-linker amount, and monomer ratios. The batch mode was applied for the investigation of copper removal from their aqueous solutions using the synthesized polymer. Besides, the theoretical models were checked for experimental data to describe the nature of the adsorption process. Also, the confirmation of adsorption was evaluated using SEM, EDX, XRD, and FTIR to explain the adsorption processes. Furthermore, desorption prepared polymer was tested and the results exhibited that the HNO₃ is the best desorption agent. The reusability of the synthesized polymer also was examined for six cycles and the results confirmed that there is no remarkable change in the uptake of polymer.