Nancy Quaranta obtained her Ph.D. in Chemistry at the National University of South (UNS-Argentina). She is a researcher of the Scientific Research Commission of Buenos Aires Province. She is the head of Environmental Studies Group and Materials Program Coordinator at the National Technological University. Her current research fields are materials and environmental sciences. She is author of numerous publications and presentations at intern ational congresses. In the last years, her work has been oriented to the study and valorisation of industrial wastes, in particular residual biomasses of the agroindustry
Olive stones is a waste that had been widely used as biofuel in diverse industries and as heating in homes, hotels and municipal facilities. The crushed olive pit is also used as an adsorbent after being converted to active carbon by increasing its specific surface area. This material, in the form of powder or granular, has various applications as a\r\n \r\n\r\n300\r\n\r\n200\r\n\r\n100\r\n\r\n0\r\n\r\n-100\r\n \r\n\r\n\r\n\r\n324\r\n\r\n343\r\n \r\n\r\n484\r\n \r\n\r\n\r\nolive stone\r\n30\r\n\r\n20\r\n\r\n10\r\n\r\n0 \r\nfilter for water treatment in chemical and pharmaceutical\r\nindustries. In recent years, this residual material has been used as an adsorbent without pretreatment or with a series of pretreatments for the removal of metal ions in industrial waste water. The objective of these investigations is the physicochemical and environmental characterization of this residual material and the feasibility analysis of its use as a pore former in ceramic matrices. This material has been characterized with the following techniques: scanning electron microscopy with semi quantitative chemical analysis (SEM-EDS), differential thermal and thermogravimetric analysis (DTA-TGA), X ray diffraction (XRD), ecotoxicity, among others. Figure 1 shows the microscopic appearance of the broken stones by SEM. DTA- TGA analysis of this material is shown in Figure 2. It can be seen some exothermic peaks corresponding to the combustion of hemicellulose, cellulose and lignin phases. This organic material is burned in a wide temperature range, between 250°C and 550°C. This is important to ensure that when this material is incorporated into clay mixtures as pore former, the sintering process takes place without crack formation in the brick. XRD analysis presents some peaks corresponding to semi crystalline cellulose at\r\n21.8, 31.7, 34.5 and 45.3 degrees. The ecotoxicity essay demonstrates that this type of waste can influence the development of sensitive species, when it is deposited on land without control. Therefore, special care must be taken during the stocking of this material when it is used as raw material of other processes, for example in construction industry.\r\n
Tengiz Kantaria has his expertise in the preparation and characterization of nanoparticles on the basis of amino acid based biodegradable poly(ester amide)s (MS thesis, 2015). Currently as a PhD student he is engaged in the synthesis and characterization of new biodegradable polymers (polyesters, polyamides, and poly(ester amide)s) via Cu(I) catalyzed alkyne–azide 1,3-cycloaddition click reaction.
Thanks to mild reaction conditions, functional group tolerance and quantitative yields click reactions are extensively used for the synthesis of a variety of polymer constructs including functionalized polymers and biopolymers, block copolymers, cyclic polymers, etc., “Click chemistry” (CC) is a rapidly growing field of research. Surprisingly, there are only few papers on the application of CC in step-growth polymerization (SGP) as a chain propagation reaction, and, to our best knowledge, there are no examples of the synthesis of biodegradable polymers such as aliphatic polyesters (PEs), polyamides and poly(ester amide)s via CC.\r\nThe present study is the first attempt of the synthesis of new biodegradable “clicking” polyesters on the basis of non-toxic building blocks such as fatty diols and dicarboxylic acids using click chemistry-based SGP. Among a variety of click reactions we have selected copper(I) catalyzed alkyne–azide 1,3-cyclo¬addition reaction due to availability of starting reagents for obtaining suitable monomers leading to the formation of 1,2,3-triazole cycles. It is expected that the insertion of 1,2,3-triazole groups in the PEs backbone can, firstly, improve their thermal characteristics; secondly, a weak basicity of 1,2,3-triazole cycle can catalytically influence their non-specific hydrolysis (biodegradation), and, finally, the possibility of quaternization of 1,2,3-triazole cycles using halo-alkyls opens a way to positively charged systems - either water soluble polymers or cross-linked hydrogels both promising for various biomedical applications. \r\nSynthesis of the new PEs has been carried out on the basis of di-propargyl esters of dicarboxylic acids and di-(bromoacetic acid)-alkylene diesters in the presence of sodium azide via tricomponent in situ click reaction (Scheme 1).\r\nOptimal reaction parameters (catalyst, solvent, solution concentration, reaction temperature, etc.) for the new click SGP have been established and the resulting PEs have been characterized by FTIR, NMR, GPC, visco¬simetry and DSC.\r\n