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Photocatalytic degradation of the carbamate insecticide methomyl and its commercial product Lannate-90 in aqueous suspension of TiO2 and ZnO using an Osram ultra-vitalux' lamp (315-400 nm) was investigated. The objective of the investigation was to study and compare the rates of photochemical degradation of the pure active compound and its formulated product in order to find out the impact of inert ingredients on degradation processes. The photochemical degradation of pure methomyl was found to be slower than the degradation of its commercial product Lannate-90. Photodegradation was investigated by UV-Vis spectrometry and HPLC, while mineralization was monitored using IC and TOC analyses. Light absorption capabilities of catalysts were characterized by ultraviolet-visible diffuse reflectance spectroscopy method, while the stability of catalysts was studied by infrared analyses. Degradation products of methomyl and its formulated product were identified by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) results and tentative photodegradation pathways were proposed.

Urea‐formaldehyde resin (F/U ratio of 0.8)/thermally activated montmorillonite (UF/ΔTK10) nanocomposite was synthesized. The hydrolytical, thermal, and UV radiation stability of UF/ΔTK10 nanocomposites are determined. UF hybrid nanocomposites have been irradiated with UV light with a wavelength of 254 nm and 366 nm, and after that, their radiation stability was evaluated. The free formaldehyde (FA) percentage in all prepared samples was determined. The sample was characterized by using X‐ray diffraction analysis (XRD), nonisothermal thermogravimetric analysis (TGA), differential thermal analysis (DTA), and differential thermal gravimetry (DTG), with infrared (FTIR) spectroscopy. Crosslinked UF/ΔTK10 nanocomposite shows the highest resistance to acid hydrolysis after UV irradiation at a wavelength of 254 nm. The values for T5% are identical for the unirradiated and UV irradiated (wavelength of 366 nm) UF/ΔTK10 nanocomposite. It can be concluded that this sample is thermally most stable and shows good resistance to UV irradiation. [ABSTRACT FROM AUTHOR]

The sorption ability of biogenic hydroxyapatite (BHAP) towards heavy metal ions (Pb, Cu, Ni, Cd, and Zn) is compared with functionalized BHAP powders with caffeic acid (CA) and 3,4-dihydroxybenzoic acid (3,4-DHBA). The functionalization of the BHAP with either CA or 3,4-DHBA is indicated by the appearance of the colored powders due to the formation of the interfacial charge transfer (ICT) complexes. The detailed characterization of as-prepared and functionalized BHAP samples was performed using transmission electron microscopy, reflection spectroscopy, thermogravimetric analysis and determination of zeta potential. All three sorbents clearly displayed preferential sorption of Pb ions when the total concentration of multi-component equimolar solutions of heavy metal ions is high. It should be emphasized that the sorption capacity of functionalized BHAP with either CA or 3,4-BHAP was found to be higher, up to 60%, compared to as-prepared BHAP without the decrease of selectivity towards Pb ions. [ABSTRACT FROM AUTHOR]

In this applicative work, two types of silica filler were used to increase the adhesion strength between steel and elastomeric hybrid materials based on chlorosulfonated polyethylene rubber (CSM) and polychloroprene rubber (CR) as network precursors. Precipitated silica (PS) with the average size of primary particles 15 nm and diatomaceous earth (DE) with the average size of primary particles 28 μm were used to ascertain differences in metal‐elastomer compounds adhesion strength caused by different particle size. The ratio of network precursors in CSM/CR rubber blends was 50:50 (w/w). The filler loading was in the range of 0–35 phr. Characteristics of the obtained composites were examined by combining the cure kinetics, adhesion strength and the dynamic mechanical properties. The viscoelasticity of obtained hybrid materials was assessed by the mechanical spectrometer (in a single cantilever bending mode) in the temperature range from −50 °C to 150 °C using multifrequency mode. POLYM. COMPOS., 40:3056–3064, 2019. © 2018 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

The powder recycled rubber (PRR) can be used as a filler and a modifier for elastomeric materials and asphalt. Composites based on elastomers and recycled rubber powders are a serious challenge for the environment. The main goal of this paper was to study the effect of rubber powder on the mechanical properties of elastomeric composites based on three precursors of the network. Triple blends were prepared using non‐polar natural rubber (NR), polyisoprene rubber (BR), and styrene‐butadiene rubber (SBR) (mass ratio 40/40/20). In all rubber compounds, the carbon black (CB)/PRR mass ratio is constant (60). Samples were prepared using two roll mill. The characteristics of hardening (optimum cure time, scorch time, minimum and maximum torque) of rubber mixtures were tested. Tensile strength, modulus at 100% elongation and elongation at break are decreasing with PRR ratio is increasing. It is due to poor adhesion of PRR into NR/BR/SBR/CB matrix. The thermal degradation temperature shifts to a higher temperature up to 5 phr of PRR in NR/BR/SBR/CB rubber blends. Fourier‐transform infrared spectra of NR/BR/SBR/CB/PRR samples show that the absorption bands shifted 7–15 cm−1 to higher wavenumbers and confirmed rubber–filler interaction. Morphology was assessed by scanning electron microscopy. POLYM. COMPOS., 40:1307–1314, 2019. © 2018 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]