Comparative analysis of the structure of coals of different stages of metamorphism according to 13C NMR data

In this paper, the method of cross-polarization with magic angle rotation and decoupling from protons (CPMAS) 13C NMR spectroscopy obtained quantitative data on the distribution of carbon over structural fragments and calculated the degree of aromaticity (fa) of some coal samples from various Siberian deposits of a wide range of metamorphism. All the coals used in the work were characterized by standard methods (proxymate and ultimate analysis). The optimal parameters of the pulse program for recording the spectra of coals have been determined. To obtain quantitative data, the spectra were simulated. The spectrum model included from 9 to 13 components, depending on the stage of coal metamorphism. The dependences of the degree of aromaticity and the sum of oxygen-containing functional groups on the stage of coal metamorphism were constructed. The results obtained show that the structure of coals regularly changes depending on the stage of their metamorphism. The revealed relationships of the structure and properties of coals, together with the parameters of their reactivity, can ensure the safe behavior of coals in the processes of mining and processing, as well as in determining possible ways of using the studied coal samples as a valuable chemical raw material.

Cutin from Solanum Myriacanthum Dunal and Solanum Aculeatissimum Jacq. as a Potential Raw Material for Biopolymers

Plant cuticles have attracted attention because they can be used to produce hydrophobic films as models for novel biopolymers. Usually, cuticles are obtained from agroresidual waste. To find new renewable natural sources to design green and commercially available bioplastics, fruits of S. aculeatissimum and S. myriacanthum were analyzed. These fruits are not used for human or animal consumption, mainly because the fruit is composed of seeds. Fruit peels were object of enzymatic and chemical methods to get thick cutins in good yields (approximately 77% from dry weight), and they were studied by solid-state resonance techniques (CPMAS 13C NMR), attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), atomic force microscopy (AFM) and direct injection electrospray ionization mass spectrometry (DIESI-MS) analytical methods. The main component of S. aculeatissimum cutin is 10,16-dihydroxypalmitic acid (10,16-DHPA, 69.84%), while S. myriacanthum cutin besides of 10,16-DHPA (44.02%); another two C18 monomers: 9,10,18-trihydroxy-octadecanoic acid (24.03%) and 18-hydroxy-9S,10R-epoxy-octadecanoic acid (9.36%) are present. The hydrolyzed cutins were used to produce films demonstrating that both cutins could be a potential raw material for different biopolymers.

Quaternized triethanolamine-sebacoyl moieties in highly branched polymer architecture as a host for the entrapment of acid dyes in aqueous solutions

This paper reports the synthesis of a hyperbranched polymer by a cost-effective one-step copolymerization of A3 and B2 monomers, namely, triethanolamine and sebacoyl chloride, respectively, followed by methylation of tertiary amine groups. The structure of the hyperbranched polymer QTEAS as an efficient material for the removal of acid dyes was demonstrated by Fourier transform infrared spectroscopy (FTIR), cross polarization magic angle spinning (CPMAS) 13C NMR, thermogravimetric analysis (TGA), powder X-ray diffraction (DRX) and scanning electron microscopy (SEM). The removal of indigo carmine (IC) and Evans blue (EB) was expected to be driven by the electrostatic attraction between positively charged quaternary ammonium groups within the hyperbranched polymer and the negatively charged dyes. The removal process was found to be closely connected to the total number of sulfonate groups on the surface of the dyes. Nonetheless, the ionic strength does not affect the dyes' removal efficiency by the hyperbranched polymer. The sorption capacities at saturation of the monolayer qmax were determined to be 213.22 mg g−1 and 214.13 mg g−1, for IC and EB, respectively, thus showing the greater affinity of QTEAS sorbent for both dyes. Despite its extended molecular structure, EB is removed with the same effectiveness as IC. Finally, the great efficiency of the highly branched polymer for dye removal from colored wastewater was clearly demonstrated.