Summary: The effectiveness of some thermoplastic elastomers grafted with maleic anhydride (MA) or with glycidyl methacrylate (GMA) as compatibilizer precursors (CPs) for blends of low density polyethylene (LDPE) with polyamide‐6 (PA) has been studied. The CPs were produced by grafting different amounts of MA or GMA onto a styrene‐block‐(ethylene‐co‐1‐butene)‐block‐styrene copolymer (SEBS) (KRATON G 1652), either in the melt or in solution. A commercially available SEBS‐g‐MA copolymer with 1.7 wt.‐% MA (KRATON FG 1901X) was also used. The effect of the MA concentration and of other characteristics of the SEBS‐g‐MA CPs was also studied. The specific interactions between the CPs and the blends components were investigated through characterizations of the binary LDPE/CP and PA/CP blends, in the whole composition range. It was demonstrated that the SEBS‐g‐GMA copolymers display poor compatibilizing effectiveness due to cross‐linking resulting from reactions of the epoxy rings of these CPs with both the amine and the carboxyl end groups of PA. On the contrary, the compatibilizing efficiency of the MA‐grafted elastomers, as revealed by the thermal properties and the morphology of the compatibilized blends, was shown to be excellent. The results of this study confirm that the anhydride functional groups possess considerably higher efficiency, for the reactive compatibilization of LDPE/PA blends, than those of the ethylene‐acrylic acid and ethylene‐glycidyl methacrylate copolymers investigated in previous works.
SEM micrograph of the 75/25 LD08/PA blend (with 2 phr SEBSMA1). 相似文献
The effect of the quality of ebullated bed vacuum residue H-Oil hydrocracking gas oils cracked in a commercial fluid catalytic cracking unit (FCCU) on its performance was studied. Six different catalysts were employed in this study. Four catalysts were tested in a commercial FCCU, and two in a laboratory FCCU. An increase of the H-Oil hydrocracker reaction temperature was associated with a decrease in the KW factor of the H-Oil gas oils. The diminished KW factor of H-Oil gas oils resulted in lower FCCU conversion and higher regenerator temperatures. The FCC conversion at maximum gasoline yield is best predicted by the feed KW factor. The higher-activity, higher-Δcoke catalyst is unfavorable for FCCU performance because the excessive regenerator temperature excursions require reduction of the throughput. 相似文献
Patterned thin films, ZnO, are successfully prepared on glass substrates by the sol-gel method using dip-coating technique.
The films, formed of ZnO nanocrystallites with hexagonal crystal structure, are characterized by means of scanning electron
microscopy, Fourier transform infrared spectroscopy and X-ray diffraction. The as obtained ZnO films are studied with respect
to photo-initiated bleaching of malachite green in aqueous solutions. The bleaching process is investigated at various initial
concentrations of malachite green in the aqueous solutions by using ZnO films of different thicknesses. The obtained results
are promising for the development of ZnO photocatalysts by the sol-gel method. 相似文献
Melanoma develops from malignant transformations of the pigment-producing melanocytes. If located in the basal layer of the skin epidermis, melanoma is referred to as cutaneous, which is more frequent. However, as melanocytes are be found in the eyes, ears, gastrointestinal tract, genitalia, urinary system, and meninges, cases of mucosal melanoma or other types (e.g., ocular) may occur. The incidence and morbidity of cutaneous melanoma (cM) are constantly increasing worldwide. Australia and New Zealand are world leaders in this regard with a morbidity rate of 54/100,000 and a mortality rate of 5.6/100,000 for 2015. The aim of this review is to consolidate and present the data related to the aetiology and pathogenesis of cutaneous melanoma, thus rendering them easier to understand. In this article we will discuss these problems and the possible impacts on treatment for this disease. 相似文献
In vitro activity of nine cyanobacterial and ten microalgal newly isolated or culture collection strains against eight significant food‐borne pathogens has been evaluated and compared. Water extracts and culture liquids of Gloeocapsa sp. and Synechocystis sp. demonstrated the widest spectrum of activity with minimal inhibitory concentration (MIC) ranging from 1.56 to 12.5 mg mL?1. Culture liquid of Anabaena sp. had the highest activity (MIC = 0.39 mg mL?1) but only to Gram‐positive bacteria. Ethanol extracts and fatty acids from all cyanobacteria and microalgae were active against Streptococcus pyogenes and/or Staphylococcus aureus. The fatty acids of Synechocystis sp. inhibited the growth of Bacillus cereus, Escherichia coli and Candida albicans (MIC values of 2.5–1.25 mg mL?1, respectively). Exopolysaccharides (EPS) of Gloeocapsa sp. were the sample that exhibited activity against all test pathogens with lowest MIC values (0.125–1 mg mL?1). High activity with a narrower range of susceptible targets demonstrated the exopolysaccharides of Synechocystis sp. and Rhodella reticulata. Antimicrobial activity was proven for phycobiliproteins isolated from Synechocystis sp., Arthrospira fusiformis, Porphyridium aerugineum and Porphyridium cruentum, respectively. In conclusion Gloeocapsa sp. and Synechocystis sp. and especially their exopolysaccharides showed the most promising potential against the examined food pathogens. 相似文献
Ninety radar signatures were digitally recorded during the probing of ten different land and marine objects with a pulsed coherent Doppler radar. Their spectra were evaluated on the basis of the Marple algorithm for autoregressive model fitting. An attempt at classification is made. The method consists in representing the radar signatures as points in four-dimensional space and identifying the obtained clusters of four-dimensional points with the observed objects. The cluster analysis is carried out assuming that the classification parameters have different clustering lengths 相似文献