Dr.Gigimol M.G is a Research Guide (Chemistry) of M.G University. Now working as Assistant professor in Chemistry at Alphonsa College Pala, Kerala, India. Dr.Dhanya K.R is a Post doctoral Fellow at M.G University, Kottayam, Kerala.
Water is the most precious natural resource that exists on our planet. Water pollution affects human health and life. The resources of water on earth are limited and are reducing every year. It is a well-known fact that clean water is absolutely essential for healthy living. In modern countries, untreated sewage, poorly treated sewage, or overflow from under-capacity sewage treatment facilities can send disease-bearing water into rivers and oceans. Many textile industries use dyes to colour their products. These dyes tend to be disposed in industrial waste water and possess several life threatening problems. Malachite Green is a toxic chemical which can lead to many diseases including carcinogenicity. The chemical was classified a Class II Health Hazard because it is found to be toxic to human cells and might cause liver tumor formation. To avoid the dangerous accumulation of dyes in the aquatic system, removal of waste materials is necessary. Amongst the numerous techniques of dye removal, adsorption is a useful tool for protecting the environment.. TTEGDA-crosslinked N-vinyl pyrrolidone-acrylic acid is the adsorbent used. Varying conditions like effect of temperature, nature and degree of crosslinking, amounts of polymer and concentration of dye solution have been studied. Weight of dye bound increases when the concentration of the dye increases. Weight of dye bound also varies with varying crosslink density. Characterization of the dye and dye bound polymeric hydrogel was carried out by IR, UV and SEM. From the results, it was clearly found that TTEGDA-crosslinked NVP-AA is an efficient adsorbent for the removal of Malachite Green from water
Over the last decade, chemical industries seek to develop new building bricks to produce biopolymers using sustainable carbon sources. Lignin is one of the most available and cheapest by-products in biorefineries where it is currently burnt to produce energy1. Polyurethanes are a family of polymers mainly used as foams or elastomers. They are usually made from isocyanate monomers which are toxic. This study proposes the synthesis of new polyurethanes made of ferulic acid derived from lignin. A macrobisphenol is firstly synthesized from ferulic acid by a chemo-enzymatic process2,3,4. It is then turned into a bisepoxide monomer5. After a carbonation step, the resulting biscarbonate is cured with a diamine. Two Non-Isocyanate Poly Urethanes (NIPU) were synthesised: one with an aliphatic diamine (1,10 diaminodecane) and the other with a cyclic diamine (isophoronediamine)6. They are hereafter called BDF-DA10 and BDF-IPDA. BDF-DA10 and BDF-IPDA were mixed together at a 1:1 ratio, in a single-screw extrusion process at 70°C and 25 rpm. The resulting material (NIPU-mix) was quite brittle at ambient temperature and became very ductile above its glass transition temperature (25 °C). A Confocal Raman Imaging experiment confirmed a good mixing of the two NIPU by following the dispersion of the cyclic diamine in the final material. Fluorescence spectroscopy revealed differences of fluorescent properties between BDF, BDF-DA10 and BDF-IPDA. Investigations were led to determine the influence of the chemical bonds and that of the spatial configuration of polymeric chains on the fluorescence.