Through in situ Generation of Iodine Monochloride. -A simple process for the synthesis of iodoarenes proceeds via in situ generation of ICl. The 4-iodo-2-nitro aniline (IIc) is successfully employed for the synthesis of 3,3',4,4'-tetraaminobiphenyl, an important monomer for polymers used in fuel cells. -(EMMANUVEL, L.; SHUKLA, R. K.; SUDALAI*, A.; GURUNATH, S.; SIVARAM, S.; Tetrahedron Lett. 47 (2006) 28, 4793-4796; Natl. Chem. Lab., Pune 411 008, India; Eng.) -Mais 43-069
PurposeTo prepare modified epoxy resins from resorcinol, cresol and phenol for improved adhesion and chemical resistance. To evaluate the properties of such modified epoxy resins.Design/methodology/approachEpoxy novolac resins (ENRs) were synthesised by condensing epichlorohydrin with novolacs based on different types of substituted phenols for improving adhesion and chemical resistance. Various compositions were made by incorporating different proportions of polyamide resin. The chemical and adhesive strengths of the conventional epoxy and the modified epoxy resins were characterised.FindingsThe modified ENR using substituted phenols showed significant enhancement of chemical and adhesive strengths over the conventional DGEBA resin. The modified ENR had an increased number of glycidyl groups (thus increased functionality) of resin, which was responsible for improved chemical and adhesive strengths over the conventional DGEBA resin.Research limitations/implicationsThe EPN resins used in the present context was synthesised from phenol, resorcinol and cresol and cured by polyamide resin of different amine values. Besides, it could be synthesised from phenolphthalein p‐aminophenol and p‐ter‐butylcatachol, etc.Practical implicationsThe method developed provided a simple and practical solution to improving the adhesive and chemical resistance of cured epoxy phenol novolac resins.Originality/valueThe method for enhanced adhesive and chemical resistance of cured epoxy was novel and could find numerous applications in surface coating and adhesive.
Friction stir welding is an emerging solid state joining process which is used to join metals and alloys having low weldability. In this research work experimental analysis has been performed on FSW for AA 6061 and MgZ31B A. Effect of FSW parameters like tool rpm, tool transverse speed and tool pin profile are investigated. A vertical milling head is used to produce FSW joints. Hot work tool steel (H13) is used as a tool material and total 3 number of tools are manufactured namely as cylindrical pin, tapered pin and square pin. Tool transverse feed of 10, 15 and 20 mm/min and tool rotational speed of 800, 1000 and 1200 rpm are taken for the study. A full factorial method is used for three numbers of parameters and their three levels and total 27 numbers of experiments are conducted keeping all other parameters constant. As a response weld tensile strength of joints are tested according to ASME-IX. Response surface method (RSM) and Analysis of variance (ANOVA) is adopted for the statistical analysis. Chi square method is used for the validation purpose and a strong match has been found between predicted and actual value of weld tensile strength of joints. As a conclusion it has been derived that feed of 15 mm/min, tool rotational speed of 1200 rpm and tapered pin profile gives better weld strength for the given experimental conditions. Furthermore research can be carried out on Bobbin type tool, numerical analysis and multi pass of FSW tool.
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