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Polyester-urea coatings were synthesized from corn oil with the help of a series of reactions in three different compositions by varying the amount of urea. Out of all the synthesized compositions, the best composition was optimized based on various parameters. The optimized composition was used as a matrix and graphene oxide (GO) was incorporated in three ratios, for the formulation of corn oil-based CPEUr@GO nanocomposites. Fourier transform infrared spectroscopy was used to confirm all the reactions. The physico-mechanical properties of CPEU[r.sub.2] coating were found to be the best among all the compositions. Therefore, CPEU[r.sub.2] was selected as a matrix for the inclusion of GO nanosheets to prepare CPEU[r.sub.2]@GO nanocomposites. Thermogravimetric analysis results showed that incorporation of GO enhanced the thermal stability of CPEU[r.sub.2] up to 325[degrees] C. The anticorrosive studies revealed the high impedance value of 6.5 * [10.sup.5] [ohm].[cm.sup.2] in case of CPEU[r.sub.2]@G[O.sub.0.5]. Furthermore, it can be concluded that the inclusion of 0.5 wt% GO proved to be the optimized amount to produce sustainable CPEU[r.sub.2] coatings with good performance. These CPEUr@GO nanocomposite coatings can be used for various protective purposes owing to their excellent physico-mechanical thermal as well as anticorrosive performance. Highlights * Corn oil-based polyester-urea, CPEUr, coatings were synthesized in three different compositions. * The best composition was used as a matrix for the formulation of CPEUr@GO nanocomposites. * Graphene oxide of 0.5 wt% was found to be the optimum quantity required to modify CPEUr matrix. * Thermal stability, mechanical durability as well as corrosion resistance performances were enhanced. * The environment friendly approach is suitable for the development of corrosion protective coatings. KEYWORDS corn oil, graphene oxide, nanocomposites, polyurea, 1 | INTRODUCTION Polyurea (PUr) coating represents a recent advancement in the field of coating technology, within the realm of urethane coatings chemistry. (1) PUr coatings exhibit notable mechanical strength [...]

The rapid use of additive manufacturing (AM) in electronic industry identifies the need of flexible electrically conductive materials suitable for 3D printing. Challenges like buckling of flexible filament and complexity in addition of conductive fillers makes pellet-based extrusion the most suitable alternative for part printing. In the present work, graphite powder is combined with ethylene vinyl acetate (EVA) to print flexible electrically conductive parts. EVA graphite composite with filler loading up to 30% has been investigated for its electrical conductivity and part printability. The composite made was found electrically conductive and suitable for part printing. The parts were printed on a CNC milling machine by using a retrofitted material extrusion tool with nozzle of 0.4 mm diameter and temperature range of 130-140[degrees] C. Parts were printed on a detchable heating bed placed on the milling machine setup. Samples of EVA with graphite filler by weight of 5%, 10%, 20%, and 30% were printed and were checked for electrical conductivity. When the filler content was increased from 10% to 20%, the electrical resistance of the composite was reduced by 62.6%. The presence and uniform dispersion of graphite flakes in the polymer matrix of EVA were guaranteed by the rheological and morphological characterization of the composite. Applications of 3D printable flexible electrically conductive parts lies in numerous domains including biosensors, wearable health monitoring devices, capacitors, field effective transistors, light emitting diodes, solar cells, and electronic displays. Highlights * CNC milling machine-assisted 3D printing is used for part printing. * Graphite powder is combined with EVA pellets. * Pellet-based extrusion is used to print flexible parts. * 3D printability of parts with resistivity 32.64 [ohm]-cm was achieved. KEYWORDS additive manufacturing (AM), ethylene vinyl acetate (EVA), extrusion, flexible electrically conductive polymers, graphite powder, 1 | INTRODUCTION The fundamental advantage of polymer-based additive manufacturing (AM) is rapid fabrication of parts having complicated geometries. Low weight, low cost, nontoxic nature, and workability make polymer a [...]

Multi-walled carbon nanotubes (MWCNTs) were synthesized by a microwave method. MWCNTs had filamentous shapes (10 [micro]m) and were intertwined in bundles (40-60 nm diameter). The rapid oxidation of MWCNTs with a loss of 90% of weight was observed from 530 to 630[degrees]C. 2% Residue was present at 630[degrees]C, which gradually decreased to 1.2% at 1000[degrees]C. In a silicone elastomer, increased thermal conductivity at a concentration of 8% MWCNTs was observed. The highest thermal conductivity of the nano-modified elastomer was 0.48 W/m[degrees]C with 8.0 wt% MWCNTs. The highest electrical conductivity was 2.4 * [10.sup.-5] S [cm.sup.-1] at 8.0 wt% MWCNTs. Both the thermal and electrical conductivities showed percolation behavior with the percolation thresholds at 6 and 5 wt%, respectively. The MWCNTs synthesized by microwave method gave a good power economy in comparison to MWCNTs obtained by chemical vapor deposition (CVD) on NiMg catalyst. Microwave-synthesized MWCNTs showed high stability at a potential of 250 V in an electrical resistance heater application due to the presence of Fe on the surface of MWCNTs. The developed heater can effectively operate at 220 V, which enables the use of the tubes in household appliances, such as heat fans, irons, and washing machines. Highlights * Synthesis of MWCNTs by microwave plasma treatment of ferrocene and graphite. * Characterization of MWCNTs by different techniques. * Concentration dependence of electro- and thermal conductivity of MWCNTs in elastomers. * Electro-physical parameters studies of elastomers modified with MWCNTs. * Heat generation studies in elastomeric matrix with MWCNTs. KEYWORDS ferrocene and graphite, heat dissipation, heaters, MWCNTs, thermal and electrical conductivities, 1 | INTRODUCTION The use of carbon nanotubes is very important in the production of functional materials. (1-3) The developed materials are being used in various applications including biomedicine, (4) [...]

In this work, expandable graphite (EG) was introduced to the composite of polypropylene/magnesium hydroxide (PP/MH) by melt compounding, fire performance, thermal degradation behavior, and acid resistance of the PP/MH/EG composites were investigated. The results demonstrate that the flame retardant efficiency of MH is very low by itself and there is a noticeable synergism between MH and EG in PP. The addition of proper EG can enhance flame retardancy, smoke suppression, and acid resistance of the PP/MH composite significantly at the same time. Replacing 8.7 wt% MH with 8.7 wt% EG reduces the filling grade needed for V-0 from 63 wt% MH to 56.5 wt% MH/EG mixture. The presence of EG on the composite surface hinders acid erosion of MH. There is no chemical reaction between MH and EG. Continuous intumescent char can be produced on the composite surface upon combustion, which is responsible for the much-improved flame retardancy and smoke suppression, regardless of the presence of MH on the surface area. KEYWORDS acid resistance, expandable graphite, flame retardancy, magnesium hydroxide, polypropylene, smoke suppression, 1 | INTRODUCTION As one of the most important thermoplastic polymers, polypropylene (PP) is widely used in many fields, such as plastics pipes, packaging, building materials, household appliances, and the [...]

A new Al.sup.3+ carbon paste ion selective electrode based on N,N'-bis(salicylidene)-1,3-propanediamine (SB-Salpr) was prepared for the quantification of trace Aluminum. The proposed sensor has significant selectivity and sensitivity toward Al.sup.3+ ions in the presence of a wide range of cations including alkaline, alkaline earth, intermediate and heavy metal ions. The use of multi-walled carbon nanotubes (MWCNTs) and nanosilica in the composition of carbon paste sensors caused improvements in their characteristics; these materials have suitable conductivity and can help in conducting signals through the carbon paste sensors. The electrode consisted of 3% of MWCNTs, 0.5% of nanosilica, 25% of paraffin oil, 66.5% of graphite powder and 5% of SB-Salpr ligand. The sensor shows a Nernstian response to Al.sup.3+ ions with a Nernstian gradient of 20.2 ± 0.1 in the concentration range of 1.0 x 10.sup.-6 to 1.0 x 10.sup.-2 M with the detection limit of 2.1 x 10.sup.-7 M. The sensor response is independent of pH in the range of 24 and possesses the advantages of fast response time less than 5 s. According to the obtained results, Al.sup.3+ nanocomposite carbon paste sensor exhibited good selectivity in the presence of a few metal ions. The sensor was effectively used as an indicator electrode in the potentiometric titration of Al.sup.3+ ions with ethylenediaminetetraacetic acid., Author(s): Razieh Sanavi Khoshnood [sup.1], Setareh Akbari [sup.1], Toktam Mashayekhi Chenarbou [sup.2] Author Affiliations: (1) grid.411768.d, 0000 0004 1756 1744, Department of Chemistry, Mashhad Branch, Islamic Azad University, , Mashhad, [...]