A phosphomolybdic acid/polyaniline (PMoA/PANI) optical-light photochromic inorganic/organic hybrid thin film was successfully synthesized by protonation between the the multiprotonic acid phosphomolybdic acid (H3PO4·12MoO3) and the conductive polymer polyaniline. The stable Keggin-type structure of PMoA was maintained throughout the process. Protonation and proton transfer successfully transformed the quinone structure of eigenstate PANI into the benzene structure of single-polarized PANI in the PMoA/PANI hybridized thin film, and proton transfer transformed the benzene structure of single-polarized PANI back to the quinone structure of eigenstate PANI in the PMoA/PANI hybrid thin film, as verified by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The average distribution of PMoA/PANI was observed by atom force microscopy (AFM). Interestingly, protonation of PMoA caused PANI to trigger transformation of the quinone structure into the single-polarized benzene structure, which enhanced the electron delocalization ability and vastly enhanced the maximum light absorption of the PMoA/PANI hybrid thin film as confirmed by density functional theory (DFT), electrochemistry, and ultraviolet-visible spectroscopy (UV-Vis) studies. Under optical-light illumination, the pale-yellow PMoA/PANI hybrid thin film gradually turned deep blue, thus demonstrating a photochromic response, and reversible photochromism was also observed in the presence of hydrogen peroxide (H2O2) or oxygen (O2). After 40 min of optical-light illumination, 36% of the Mo5+ species in PMoA was photoreduced via a protonation-induced proton transfer mechanism, and this proton transfer resulted in a structural change of PANI, as observed by XPS, generating a dominant structure with high maximum light absorption of 3.46, when compared with the literature reports.
A series of saturated cardanol polyoxyethylene ether carboxylates was synthesized using renewable saturated cardanol originating from Cashew Nut Shell Liquid as raw material. The structures were characterized by hydrogen nuclear magnetic resonance spectroscopy. The studies of their surface activity and interface activity were carried out to analyze the influence of the chemical structures of the series of cardanol surfactants on the adsorption and micellization. Results showed that saturated cardanol polyoxyethylene ether carboxylates had a good surface activity and interface activity, and the interface activities of the Gemini cardanol surfactants were better than those of the corresponding monomer cardanol surfactants. The critical micelle concentrations (CMC) of all investigated cardanol surfactants, obtained from surface tension measurements, were low in the order of 10−5 mol/L. The CMCs decreased and the oil-water interface tension for the same cardanol surfactants increased with the increase of the oxyethylene number. The process of micellization became easier with increasing the oxyethylene number. The ΔGθm values of the Gemini cardanol surfactants were more negative than those of the corresponding monomer cardanol surfactants. The micellization for all cardanol surfactants was a spontaneous process and exhibited enthalpy-entropy compensation. The micellization of all the cardanol surfactants was entropy-driven.
Four aliphatic diamine bridged hindered phenols were successfully synthesized with aliphatic diamine as the bridged group and 3‐(3,5‐di‐tert‐butyl‐4‐hydroxy‐phenyl)‐propionyl chloride as the material, and their structures were clarified by NMR, Fourier transform infrared spectroscopy, and mass spectrometry. Their performance as antioxidant for polypropylene (PP) and linear low‐density polyethylene (LLDPE) were investigated through the melt flow rate and the oxidation induction time. The thermooxidative stabilities of PP and LLDPE with different aliphatic diamine bridged hindered phenols were assessed by the measurement of the oxidation induction temperature and with long‐term aging testing. The results showed that aliphatic diamine bridged hindered phenols could protect two kinds of polyolefins from thermal oxidative degradation, and the mechanical properties and antioxidant activities of polyolefins stabilized with aliphatic diamine bridged hindered phenols were increased with increasing length of the bridged group for aliphatic diamine bridged hindered phenols at the same concentration of phenolic hydroxyl group. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45095.
Antiradical abilities of 1.0 generation dendrimer bridged hindered phenols (1.0G dendritic phenols) are studied by the DPPH method and antioxidant properties in polyolefin are evaluated by melt flow rate (MFR), oxidation induction time (OIT) and accelerated thermal aging test. The results indicate that the antioxidant properties are affected not only by the chemical structure but also by the reaction system for series of 1.0G dendritic phenols. The antiradical ability decreases with increasing of the length of the bridged group of 1.0 G dendritic phenols, and the antiradical abilities at steady state reaction time are better than those at fixed reaction time of 30 min. The reaction of 1.0G dendritic phenols scavenging DPPH free radical belongs to slow kinetic behavior. And 1.0G dendritic phenols have excellent processing property, oxidation resistance behavior and thermo‐oxidative aging resistance in linear low density polyethylene (LLDPE) and polypropylene (PP). The OIT values and the aging coefficient values of polyolefin stabilized with 1.0G dendritic phenols increase with increasing of the length of the bridged group of 1.0G dendritic phenols. The antioxidant abilities 1.0G dendritic phenols in LLDPE are superior to those in PP.
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