A Titanium-modified phenol-formaldehyde resin (Ti-PF) was prepared. FT-IR was adopted to characterize the molecular structure of the modified resin. And the curing behavior and curing kinetic characteristics were studied by differential scanning calorimetry (DSC). The initial curing temperature Ti, the exothermic peak temperature Tp and the end curing temperature Td of Ti-PF are 153.1°C, 172.5°C and 193.9°C, respectively, all about 10°C higher than that of the unmodified phenolic resin. The Kissinger and Crane equations were applied to establish the curing kinetic parameters of Ti-PF. The kinetic analysis indicates the activation energy for the Ti-PF is 79.9kJ•mol-1, lower than that of the unmodified phenolic resin(87.6kJ•mol-1). In addition, the thermal degradation behavior of the cured Ti-PF was studied by thermal gravimetric (TG) method. TG results show that the char yield of Ti-PF is 73.3% at 850°C, while that of the unmodified phenolic resin is only 62.3%. It demonstrated that titanium-modified phenolic resin has much better thermal stability compared with the unmodified one.
Nitrogen hybrid ordered mesoporous carbons (N-OMC) were prepared by the soft-template method with melamine-phenol-formaldehyde resoles (MPF) as the precursors and triblock copolymer F127 as a soft-template. FT-IR spectra analysis demonstrated that nitrogen was incorporated into the mesoporous carbons with C-N covalent bonds. The effect of molar ratio of phenol to melamine on the pore structure and textural properties was discussed by small angle X-ray scattering, nitrogen adsorption measurements, and transmission electron microscopy. The results show that the degree of pore order decreases with the increasing of nitrogen content. The N-OMC with 3.39 wt% nitrogen has the highest specific surface areas (573m2/g) and best ordered mesostructure.
The mono-(6-p-toluenesulfonyl)-β-cyclodextrin was firstly synthesized fast and efficiently by adopting ultrasound assisted method in alkaline water solution. The reaction time was only 40 min but with the yield of 31.1% under ultrasound condition. Compared with the conventional synthetic methods, the proposed novel method could shorten the reaction time and improve the yield. It is a simple, rapid and efficient method.
W@SiO2 shielding composite microspheres were prepared by Sol-gel method for the first time. The component and morphology were investigated by Fourier transform infrared (FT-IR) spectra, Transmission electron microscopy (TEM) and Energy dispersive X-ray spectroscopy (EDX). The results reveal that polyvinylpyrrolidone (PVP) was introduced to the surface of tungsten nanoparticle successfully, and tungsten nanoparticle had been coated with silica. The appropriate hydrolysis reaction time is 3h, core-shell structure W@SiO2 shielding composite microsphere can be synthesized and free silica decrease sharply. Core element and shell element of W@SiO2 shielding composite microspheres were proved to be tungsten and silica respectively.
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