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Catalytic stability and ethylene selectivity were significantly improved through adding K into Cr-based catalysts in oxidative dehydrogenation of ethane with CO2. A series of K promoted Cr catalysts with different K loading were prepared by impregnation method using Ce-Zr solid solution as support. The porosity, crystalline phase, surface chemical state, lattice oxygen property, redox, basicity etc. were investigated, and the results showed that high content of K would enrich surface Cr6+ and O species through the formation of K2CrO4/K2Cr2O7, which further improved the surface basicity. All of these factors acting to conversion and selectivity should be well coordinated to obtain a good productivity of ethylene. The introduction of K helped the desorption of ethylene from active sites and stabilized the reaction within times on stream of 50 h. The introduction of surface K species suppressed the dry reforming but promoted the selective oxidation to produce ethylene.

A significantly growing interest is to design new biodegradable polymers in order to solve fossil resources and environmental pollution problems associated with conventional plastics. A kind of new biodegradable polymers, aliphatic–aromatic co-polyesters have been researched widely and developed rapidly in recent years, since that can combine excellent biodegradability provided from aliphatic polyesters and good properties from aromatic polyesters. Out of which, poly (butylene-adipate-co-terephthalate) (PBAT) shows the most importance. PBAT has been commercialized by polycondensation reaction of butanediol (BDO), adipic acid (AA) and terephthalic acid (PTA) using general polyester manufacturing technology. And it has been considered to have desirable properties and competitive costs to be applied in many fields. Therefore, this review aims to present an overview on the synthesis, properties and applications of PBAT. Keywords: Biodegradation, Polyester, PBAT, Synthesis, Property, Application

Standard high resolution 13C NMR spectra of PA10T, PA6T, PA106, and PA66 were obtained by a nonacidic solvent mixture of HFIP and CDCl3. Several chemical shifts were found extremely sensitive to th...

The study on toughening and reinforcing of bisphenol-A epoxy resin is one of important developmental direction in the field. This paper reports a one-pot synthesis of aromatic polyester hyperbranched epoxy resin HTDE-2, an effect of HTDE-2 content on the mechanical and thermal performance of the bisphenol-A (E51)/HTDE-2 hybrid resin in detail. Fourier transform infrared (FT-IR) spectrometer, scanning electronic microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), dynamic mechanical thermal analysis (DMA) and molecular simulation technology are used to study the structure of HTDE-2, performance and toughening and reinforcing mechanism of the HTDE-2/E51 hybrid resin. It has been shown that the content of HTDE-2 has an important effect on the performance of the hybrid resin, and the performance of the HTDE-2/E51 blends has maximum with the increase in HTDE-2 content. The impact strength and fracture toughness of the hybrid resin with 9 wt-% HTDE-2 are almost 3.088 and 1.749 times of E51 performance respectively, furthermore, the tensile and flexural strength can also be enhanced about 20.7% and 14.2%, respectively. The glass transition temperature and thermal degradation temperature, however, are found to decrease to some extent.

Poly(decamethylene terephthalamide) PA10T with different relative viscosities (RV) were successfully produced by the reaction of 1,10-decanediamine and terephthalic acid through molecular weight regulator benzoic acid (BA). RV was shown to be decreased linearly with increasing BA concentrations and detailed structures of PA10Ts were characterized by 13C-NMR. Fluidity of PA10T with varying molecular weight was tested and low RV PA10Ts were used as modifiers to improve fluidity behaviors of high RV PA10Ts, meanwhile mechanical properties were maintained. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40058.