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This study examined the effects of matrix (PVA and Si) on the properties of TEMPO-treated nanocomposites preparing from different pulp sources (Kraft and NaBH treated Kraft). Chemical characterization and crystallization were determined via FT-IR, thermal stability via TGA and morphological alterations via SEM. UTM and DTMA were used to measure the Young's and storage moduli. The real and imaginary parts of permittivity and electric modulus were evaluated using an impedance analyzer. After interaction, prominent vibrations and alteration of crystallinity were seen. Storage and Young's moduli decreased after Si and PVA interaction. The Si-TOCN films showed higher permittivity properties and all of the films followed a similar trend of significantly dropping ε' and ε'' values at high frequency. The PVA-TOCN films had mechanical advantages at room temperature compared to the Si-TOCN films. However, the Si-TOCN films had better thermomechanical properties at high temperatures. NaBH revealed favorable effects on mechanical properties of the films. [ABSTRACT FROM AUTHOR]

Industrial applications of microfibrillated cellulose (MFC) and nanofibrillated cellulose (NFC) have been in use for some time; however, there is a need to improve the production steps and at the same time to obtain better quality products. NFC and MFC were generated from $$\hbox {NaBH}_{4}$$ -modified kraft pulp, produced from a red gum tree plant ( Eucalyptus camaldulensis). The generated NFC and MFC were characterized by high-performance liquid chromatography, Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA) and $$^{13}\hbox {C}$$ -nuclear magnetic resonance (NMR). Morphological and viscoelastic properties were investigated by scanning electron microscopy and rheometry, respectively. The storage moduli of biofilms produced from NFC and MFC were investigated by dynamic mechanical thermal analysis (DMTA). Both exhibited mostly identical FTIR spectra. When the spectra were compared with those of $$\hbox {NaBH}_{4}$$ -modified kraft pulp, minor shifts were observed due to crystallinity. In NMR spectra, disordered cellulose structures were observed for both NFC and MFC, and these findings were also confirmed by differential scanning calorimetry. Rheology studies revealed that the lowest viscosity was observed with MFC. TGA results showed that NFC degraded earlier compared with $$\hbox {NaBH}_{4}$$ -modified kraft pulp. DMTA exhibited that NFC films had about six times higher storage modulus compared with MFC. [ABSTRACT FROM AUTHOR]

The free-radical copolymerization of 2-methyl- N-1,3-thiazole-2-ylacrylamide monomer (TMA) with glycidyl methacrylate (GMA) was carried out in 1,4-dioxane at 65 ± 1 °C using azobisisobutironitril (AIBN) as an initiator. The copolymers were characterized by FTIR, 13C-NMR and 1H-NMR spectroscopic methods. The copolymer compositions were determined by elemental analysis. The weight-average and number-average molecular weights of the copolymers were obtained by gel permeation chromatography (GPC). The polydispersity indices of the polymers, determined with gel permeation chromatography, suggested a strong tendency for chain termination by disproportionation. Thermal properties of the polymers were also studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The monomer reactivity ratios were calculated according to the general copolymerization equation using Kelen–Tudos and Fineman–Ross linearization methods. The reactivity ratios indicated a tendency toward for alternation. The thermal decomposition activation energies of the polymers were evaluated by Ozawa method. The antibacterial and antifungal effects of the copolymers were also investigated on various bacteria and fungi. All the products showed moderate activity against different strains of bacteria and fungi. [ABSTRACT FROM AUTHOR]