Improved Wear-Resistant Performance of Epoxy Resin Composites Using Ceramic Particles

This work investigated the effects of using a new fabrication technique to prepare polymer composite on the wear-resistant performance of epoxy resin composites under dry friction conditions. Polymer composite samples with different weight contents of silicon carbide (SiC) particles were manufactured. This paper addresses the wear behavior of the obtained samples. With the suggested technique, the samples were prepared from epoxy/silicon carbide particles using a layer of thin kraft paper to prevent the sedimentation of the ceramic particles and to control the weight content of ceramic in the polymer. Kraft paper was used as a layer in the polymer composite. The hardness, wear resistance, and water absorption capacity of the produced epoxy composite samples prepared using the kraft paper technique were evaluated. The morphology of epoxy composite samples showed a significant improvement in the ceramic distribution and enhancement of interface bonding between ceramic and the polymer. The hardness values of the developed polymer composites were enhanced by up to 42.8%, which was obtained at 18 wt.% SiC particles. Increasing the ceramic content in the epoxy also led to the enhancement of wear resistance compared with pure epoxy. The results of the microstructure study also showed that the kraft paper layers helped in maintaining the distribution of the ceramic particles according to the previously specified content in each layer in the sample. Wear tests showed that the wear rate of the polymer composite decreased with the increase in the ceramic content. This study provides a new recycling method for using old kraft paper in polymer composite manufacturing to improve the distribution of ceramic particles in the polymer matrix.

Reinforcement of Protective Coatings Based on Powder Paints with Alumina Nanofibers

The paper deals with the production and study of nanocomposite powder paints based on alumina nanofibers. For nanodispersed fillers, the nature of the surface states on the filler particles is important. The problem of introducing nanomaterials into a polymer matrix cannot provide an effective solution without matching the surface states of the nanomaterial filler and the polymer matrix for the resulting composite materials. The consistency of the surface states of the nanomaterial filler and the polymer matrix determines the quality of transfer of the necessary properties to the resulting polymer composite. In order to increase the affinity of alumina nanofibers with a matrix of powder paint, the nanofibers were treated with 3-glycidyloxypropyltrimethoxysilane (GLYMO) in toluene. It is shown in the work that the addition of alumina nanofibers leads to a hardening of the coating, an increase in its elasticity, and an increase in corrosion resistance. Finishing of alumina nanofibers in a solution of silane in toluene leads to its functionalization, which is sufficient for the distribution of nanofibers in the polymer matrix of the paint and improvement of its operational properties.

Photophysical Details and O2-Sensing Analysis of a Eu(III) Complex in Polymer Composite Nanofibers Prepared by Electrospinning

An as-synthesized Eu(III) complex, denoted as Eu(N-DPNQ)(TTD)3, was prepared and characterized, and the antenna mechanism between these ligands and central metal emitter was studied. Here DPNQ means 10-ethyl-10H-indolo [2′,3':5,6]pyrazino[2,3-f][1,10]phenanthroline and TTD is 4,4,4-trifluoro-1-(thiophen-2-yl)butane-1,3-dione. We find that Eu(N-DPNQ)(TTD)3 emission intensity dependents on oxygen concentration, and O2-sensing skill of Eu(N-DPNQ)(TTD)3 in polymer composite nanofibers of poly (vinylpyrrolidone) (PVP) prepared by electrospinning is investigated. Results reveal that the emission quenching of Eu(N-DPNQ)(TTD)3 is caused by the ground state (triplet) oxygen quenching on antenna ligands triplet state. The Eu(N-DPNQ)(TTD)3 doped composite nanofiber with a loading level of 6 wt% exhibits the best result with sensitivity of 2.43 and response time of 10 s, along with linear response.