Curing studies of unsaturated polyester resin used in FRP products

31-39Fiber reinforced plastics (FRP) products being strong and light in weight, find extensive applications in automobiles, marine, structural and household components. Unsaturated polyester (UP) resin is a principle binder material used in FRP products. Curing of UP resin is a key for successful FRP processing. Gel time (tgel) and peak exothermic temperature (θpeak) are critical measures of curing of resin. tgel indicates commencement of polymer cross-linking (setting) while θpeak controls shrinkage and cracking of polymer. This paper aims to predict the tgel and θpeak during cure of UP resin. The weight percent of methyl ethyl ketone peroxide (MEKP) as catalyst, cobalt octoate (Coct) as an accelerator, calcium carbonate (CaCO3) as filler and glass fibers as reinforcements are used as process variables. The variations in tgel and θpeak are approximated by regression equations. Strong interactions are found between the process variables. The process optimization is made to achieve a desired combination of tgel and θpeak within the regime of experimentation. Confirmatory experiments are performed to validate the predicted results

Anaerobic co-digestion of food waste and septage – A waste to energy project in Nashik city

The samples for food waste (FW) and septage were collected from six localities of Nashik city. Physical and chemical characterizations of the wastes were carried out. A Biomethanation potential (BMP) assay was developed to determine the ultimate biodegradability and associated methane yield during the anaerobic methanogenic fermentation of organic substrates. BMP assays of individual substrate, FW and septage were carried out by taking into account the volatile solids/total solids (VS/TS) ratio of each while keeping the inoculum’s VS constant. BMP of FW and septage mixture was carried out in different ratios (1:1, 1.5:1, 2:1, 1:1.5 and 1:2) to find the optimum mixing ratio for maximum biogas production. The average methane yield for different locality FW was found to be 503±17.6 ml/g VS and for septage it was 56 ±10.8 ml/g VS. Based on the above results, the total biogas yield and total methane yield for 10 tons of FW would be 2178 m3/d and 1306 m3/d respectively. The total biogas yield and total methane yield for 20 m3 of septage would be 65m3/d and 39m3/d respectively. From our co-digestion studies we also conclude that the mixture of FW to septage at 1:2 ratio gives 2896 m3/day of biogas. The role of septage is to provide essential trace elements that are required for methanogens

Biocompatible agarose-chitosan coated silver nanoparticle composite for soft tissue engineering applications

<p>With increasing gap in the demand and supply of vital organs for transplantation there is a pressing need to bridge the gap with substitutes. One way to make substitutes is by tissue engineering which involves combining several types of synthetic or biomaterials, cells and growth factors cross-linked together to synthesize a functional scaffold for repair or replacement of non-functional organs. Nanoparticle based composites are gaining importance in tissue engineering due to their ability to enhance cell attachment and proliferation. The current study focuses on synthesizing agarose composites embedded with chitosan-coated silver nanoparticles using glutaraldehyde as the cross-linker. The synthesis of chitosan coated silver nanoparticles within the scaffold was confirmed with UV-visible spectroscopy. Physical and chemical characterization of the synthesized nanoparticles were done by XRD, FTIR, TGA and SEM. DMA showed higher mechanical strength of the scaffolds. The scaffolds showed degradation of ∼37% within a span of four weeks. The higher physical support provided by the synthesized scaffolds was shown by <i>in-vitro</i> cell viability assay. Broad spectrum anti-bacterial activity and superior hemocompatibility further showed the advantage it offered for growing cells. Thus a biopolymer based nanocomposite was synthesized, with intended widespread use as scaffold for engineering of soft tissues due to its enhanced biocompatibility and greater surface area for cell growth.</p