Dual functional epoxy resins were synthesized by solution polycondensation of 2,6-bis(4-hydroxy-3-methoxy benzylidene)cyclohexanone and 2,5-bis(4-hydroxy-3-methoxy benzylidene)cyclopentanone with epichlorohydrin. The synthesized epoxy resins were characterized systematically for their structure by UV, Fourier transform infrared (FTIR), 1 H NMR, and 13 C NMR spectroscopic techniques. Thermal characterization of synthesized epoxy resins was carried out by thermogravimetric analysis, and differential scanning calorimetry (DSC) under nitrogen atmosphere. The self extinguishing property of synthesized oligomers was studied by determining limiting oxygen index (LOI) values using Van Krevelen's equation. X-ray analysis showed that the epoxy resins containing cyclopentanone have higher degree of crystallinity. The photoreactive property of the synthesized epoxy resins in solution and film states was investigated by UV-Vis spectroscopy.The photocross-linking proceeds through the dimerization of olefinic chromophore present in the main chain of the oligomer via 2p þ 2p cycloaddition reaction. The influence of photoacid generator on the rate of photocross-linking of epoxy resin was studied by FTIR. UV irradiation of the epoxy resin in presence of photoacid generator produces aromatic sulfonium cation radicals and aromatic radicals which initiate the cationic ring-opening polymerization of oxirane ring. The photoreactivity studies of the oligomers by FTIR and DSC indicated the presence of dual functionality in the synthesized epoxy resins.
The effect of enzyme treatments with consecutive softening by the use of silicone – polyurethane on low stress mechanical properties and hand values of jute/cotton union fabric have been studied on the Kawabata evaluation system (KES). The results indicate that the enzyme treated, silicone – polyurethane finished fabric has significant (p<0.05) improvement in tensile resilience, fabric extensibility, compressional resistance and friction co efficient, whereas fabric thickness, linearity of tensile, surface roughness, bending and shear rigidity and their hysteresis are reduced compared to the untreated fabric. Under the Kawabata system, the Koshi (stiffness) value of the finished fabric is decreased by 1-9%. Numeri (smoothness) and Fukurami (fullness and softness) values are increased by 11-20% and 3-4% respectively compared to the untreated fabric. The variation in primary hand values are significant (p<0.05). The total hand value (THV) is also increased by 6% and 44% for the case of 40/60 and 50/50 jute/cotton union fabrics, respectively. This study confirms the possible usage of jute/cotton fabric in the apparel segment.
Natural dyes, which have been pushed to the background by synthetic colours over the past sixty years, have suddenly resurfaced as a source of consumer interest. This is because of the familiarity with potential dangers during the innovation of engineered colors which include utilization of petrochemical-based unrefined components and the brutal substance responses for their combination. The production of engineered colors is energy concentrated with unfriendly effect on climate adding to its contamination. A considerable lot of these colors, particularly the azo-based ones, are viewed as cancer-causing. A brief examination of natural colourants derived from plant sources, their sequence, and the component ingredients responsible for diverse shadings is provided in this foundation, its exercises and impact of various mordants on the tone is talked about. Various classes of mordants utilized for obsession of regular colouration on materials substrated, its instrument and plant sources are likewise examined.
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