An Aqueous Cleaning Solution for Removing Oil and Grease from Steel Components

An Aqueous Cleaning Solution for Removing Oil and Grease from Steel Component

Preparation and characterization of heat-resistant interpenetrating polymer network (IPN)

Interpenetrating polymer network (IPN) is a novel type of polymer hybrids, which possess physicochemical properties suitable for high performance coatings. Heat-resistant IPN have been prepared from immiscible resins, epoxy and silicones using a cross-linking agent and a catalyst. The products were analyzed by GPC, FT-IR, TG, DTA and SEM studies. The heat resistance property and corrosion behaviour of the IPNs were also determined. It was different from those of the individual resins. Silicone microdomains could be seen uniformly distributed in epoxy regions. Corrosion resistance property of the IPNs was evaluated by salt spray and impedance measurements. The IPNs withstood longer durations in the salt spray chamber

Physico-chemical properties of ceramic pigments for high-temperature application

Heat resistant coatings are required primarily for stacks, exhaust pipes, reactors, space crafts and similar equipments that are permanently or occasionally exposed to elevated temperatures. High-temperature coatings are generally based on silicone resin with ceramic and metallic pigments. In this study, iron oxide, cobalt oxide (thermo chromic compound) and aluminum oxide are used for the preparation of four new types of coloured pigments. The thermal resistant characteristics of these ceramic pigments were studied by differential thermal analysis, thermo gravimetric analysis and differential scanning calorimetric analysis. These ceramic pigments are found to be thermally stable up to 400 ◦C

Performance of black pigments incorporated in interpenetrating polymer network (IPN)

Interpenetrating polymer network (IPN) in which two different resins (epoxy and silicone) are not miscible as such with each other is made to do so by using cross-linking agents and catalyst. IPN possess good improved mechanical, chemical, heat and corrosion resistant properties than individual resins. Incorporation of black pigments like graphite, silicon carbide, carbon black and acetylene black has enhanced these properties because of their shape, size, acid and salt solution resistance, conducting nature and heat stability property. Flake structured graphite and hexagonal structured silicon carbide pigments in IPN protect the mild steel structures from corrosive and high temperature atmosphere for longer duration than the other pigments

Preparation and characterization of thermally stable epoxy-titanate coatings

Epoxy-polyamide coatings are used to protect metallic substrates in corrosive atmosphere. Thermal stability of the coating can be improved by the addition of inorganic cross-linking agent. Epoxy resin is incorporated with small percentage of silicone resin and cured with two types of hardeners such as polyamide and butyl titanate. The physical properties, heat resistance properties and electrochemical impedance behaviour of these coatings on steel in 0.5M NaCl solution have been studied. The result implies that the heat resistant character of the titanate-cured coating is increased from 260 to 370 ◦C. The impedance study has shown that the coating resistance exerted by both the systems is in the range of 105 �cm2 after 6 days of immersion in 0.5M NaCl. FTIR and Raman spectroscopy analysis confirm the presence of titanate linkage in the cured polymer coating. Thermal stability data indicate that the epoxy silicone resin cured with titanate hardener possesses higher thermal stability than that cured by polyamide hardener

Polypyrrole as a protective pigment in organic coatings

This study deals with the preparation and dla.racteriution of polypyrrole (PPy) using ferric chloride and ammonium dichromate as oxidants and also with the addition ofa common surfactant in aqueous solution. The combination of oxidant and surfactant in the preparation of PPy has shown that there is an enhancement in conductivity and also in the yield of the PPy. The deprotonated PPy exhibits a better stability with decreasing conductivity. Fourier tr.Insform infrared spectroscopy (FfIR) cOllfinned that the surfaetantradical sulphoxide got incorporated into-the Ppy as a dopantand also the presence ofchromate radical was indicated by the appearance of peak at 459 em _1. Thermo GravimetriC Analysis (TGA) indicates that the weight losses for PPy-Ci and PPy-CrO. are 97% and 35-50% at 1000·e. respectively. X-ray diffraction (XRD) studies also give an idea about the size and shape of the polymer. The corrosion resistance property ofPPy-incorporated coatings on mild steel substrate in sodium hloride solution indicate that the PPy-rO'./epoxy-polyamide coating gives maximum duration ofprotection compared with other systems

Non-phosgene route for the synthesis of methyl phenyl carbamate using ordered AISBA-15 catalyst

Methyl phenyl carbamate (MPC) has been synthesized under liquid phase conditions from dimethyl carbonate and aniline by using mesoporous AlSBA-15 catalyst. The catalyst with different Si/Al ratio was synthesized by isomorphous substitution of aluminium into the framework of siliceous SBA-15. The structural integrity of the catalyst system was diagnosed with the help of various characterization techniques such as X-ray diffraction, surface analysis, and the acidity measurement has been done by TPD using ammonia as probe molecule. AlSBA-15 (Si/Al = 10) exhibited highest catalytic activity in the synthesis of MPC under the reaction conditions studied. The effect of parameters such as molar ratio of reactants, catalyst concentration, reaction temperature and time on the conversion of aniline was investigated. The results demonstrated that an aniline conversion of 99% and MPC selectivity of 71% were achieved when the reaction was carried out at 100 °C, DMC to aniline mole ratio of 10 with 5% of catalyst (wt% of total reaction mixture) for 3 h

Highly Stable Passive Wireless Sensor for Protease Activity Based on Fatty Acid-Coupled Gelatin Composite Films.

Proteases are often used as biomarkers of many pathologies as well as of microbial contamination and infection. Therefore, extensive efforts are devoted to the development of protease sensors. Some applications would benefit from wireless monitoring of proteolytic activity at minimal cost, e.g., sensors embedded in care products like wound dressings and diapers to track wound and urinary infections. Passive (batteryless) and chipless transponders stand out among wireless sensing technologies when low cost is a requirement. Here, we developed and extensively characterized a composite material that is biodegradable but still highly stable in aqueous media, whose proteolytic degradation could be used in these wireless transponders as a transduction mechanism of proteolytic activity. This composite material consisted of a cross-linked gelatin network with incorporated caprylic acid. The digestion of the composite when exposed to proteases results in a change of its resistivity, a quantity that can be wirelessly monitored by coupling the composite to an inductor-capacitor resonator, i.e., an antenna. We experimentally proved this wireless sensor concept by monitoring the presence of a variety of proteases in aqueous media. Moreover, we also showed that detection time follows a relationship with protease concentration, which enables quantification possibilities for practical applications