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991.
992.
油田采出水中悬浮固体含量的测定 总被引:1,自引:0,他引:1
针对油田采出水悬浮固体含量的测试过程中暴露出的水样过滤时间长、烘干前滤膜表面滞留水量大导致测试结果重现性差和误差大的问题,提出了单个滤膜极限过滤体积的概念和水样过滤体积确定方法.通过对不同厂家微孔滤膜性能、膜滤速率曲线进行比较,优选了适宜的滤膜,有效地提高了不同实验室之间测试结果的重现性和测试精度. 相似文献
993.
TiO2 particle–polymer composite coatings were applied to the surface of a 5083 aluminum alloy. After using a knife to create an artificial defect, polarization resistance was monitored in artificial seawater at a temperature of 30 °C. The polarization resistance of the specimen coated with the composite polymer containing 3 vol% TiO2 particles increased significantly over time, suggesting that the composite coating had self‐healing properties. A carbon‐containing 2‐µm thick film was found on the coated aluminum substrate at the site of the artificial defect. The formation of the film was related to the dissolution of bisphenol A (BPA), which is a chemical precursor of the polymer coating that behaved as an inhibiting agent. 相似文献
994.
995.
Francisco López-Carrasquero Giuseppe Giammanco Angélica Díaz Johanna Dávila Carlos Torres Estrella Laredo 《Polymer Bulletin》2009,63(1):69-78
A series of comb like poly(p-n-alkylstyrene)s with linear alkyl groups, containing even numbers of carbon atoms from 12 up to 22 were synthesized by radical
polymerization and characterized by FTIR, 1H NMR, TGA, TVA DSC, and WAXS. All polymers were obtained in good yields and were soluble in organic solvents as chloroform,
dichloromethane or tetrahydrofuran and insoluble in methanol; they are stable up to temperatures near 300 °C. On the other
hand, the alkylic side chains of all series are able to crystallize in a paraffinic phase in which the melting temperature
and enthalpy increase with the methylene number of the n-alkyl chain. 相似文献
996.
A highly insoluble metalloporphyrin polymeric material was used as sorbent for the solid‐phase extraction of phenolic compounds. Substantial quantities of phenols (40 to 60 mg/g polymer) were absorbed from aqueous solution comparing satisfactorily with other extraction methods. The polymeric phase presented similar KSPE values for the hydrophobic compounds tested such as p‐chlorophenol, BPA, p‐nitrophenol, and a significant lower value for the more hydrophilic p‐aminophenol and cresol. Several metallic complexes of protoporphyrin IX (Co2+, Cu2+, Ni2+, Zn2+, and Fe3+) have been tested. The analytes were extracted with high recoveries at acid and neutral pH values, whereas at pH 10 low recoveries were obtained. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 3038–3043, 2001 相似文献
997.
A new diphenol monomer bis(4′-hydroxy-phenyl)-tolyene-2,4-diurea was synthesized by reaction of 2,4-toylene diisocyanate with p-aminophenol in N,N-dimethylformamide (DMF). The product was characterized by elemental analysis (EA), differential scanning calorimetry (DSC), and 1H-NMR. And a novel kind of liquid crystalline poly(urea-ester)s were obtained by using this monomer. By using a polarizing microscope with hot stage (POM), wide-angle X-ray diffraction (WAXD) and small-angle X-ray diffraction (SAXD) the polymers were proven to be nematic liquid crystal. The result of DSC showed that the effect of the monomer composition on the melting point of poly(urea-ester)s was significant. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 577–583, 2001 相似文献
998.
The premelting behavior of bacterially synthesized polyester poly(3-hydroxybutyrate-co-3-hydroxyhexanoate), abbreviated as P(HB-co-HHx), was investigated by two-dimensional Fourier-transform infrared (2D FTIR) correlation spectroscopy. The temperature-dependent dynamic spectra were measured over a temperature range of 25–300°C. We focused our study on the thermally induced intensity fluctuations of bands for CO (1700–1760 cm−1), C H (2910–3010 cm−1) and C O C groups (1220–1310 cm−1) stretching vibrations. Changes of crystalline conformation due to the thermal perturbation could be detected by the intensity and location variations of those characteristic bands responding to the variations of dipole moments. 2D correlation analysis indicated that the appearance of fully amorphous component did not happen simultaneously with the disappearance of crystalline component, suggesting that there was an intermediate state between ordered crystalline and amorphous states in P(HB-co-HHx). © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 934–940, 2001 相似文献
999.
The sheet‐molding process for the production of poly(methyl methacrylate) (PMMA) involves an isothermal batch reactor followed by polymerization in a mold (the latter is referred to as a “sheet reactor”). The temperature at the outer walls of the mold varies with time. In addition, due to finite rates of heat transfer in the viscous reaction mass, spatial temperature gradients are present inside the mold. Further, the volume of the reaction mass also decreases with polymerization. These several physicochemical phenomena are incorporated into the model developed for this process. It was found that the monomer conversion attains high values of near‐unity in most of the inner region in the mold. This is because of the high temperatures there, since the heat generated due to the exothermicity of the polymerization cannot be removed fast enough. However, the temperature of the mold walls has to be increased in the later stages of polymerization so that the material near the outer edges can also attain high conversions of about 98%. This would give PMMA sheets having excellent mechanical strength. The effects of important operating (decision) variables were studied and it was observed that the heat‐transfer resistance in the mold influences the spatial distribution of the temperature, which, in turn, influences the various properties (e.g., monomer conversion, number‐average molecular weight, and polydispersity index) of the product significantly. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1951–1971, 2001 相似文献
1000.
Su‐Huai Liu Shu‐Fan Zhang Zong‐Neng Qi Guang‐Li Zhang Hong‐Zhi Zhang 《应用聚合物科学杂志》2001,82(7):1653-1657
U‐Polymer, a kind of polyarylate, was synthesized by interfacial polycondensation method with terephthaloyl chloride (TPC), isophthaloyl chloride (IPC), and bisphenol A (BPA) as raw materials. The structure of the U‐Polymer was characterized by IR and 1H–NMR spectra. Then, an amorphous poly(ethylene terephthalate) (APET) was prepared with the introduction of the U‐Polymer to the PET sequence to improve thermal and mechanical behaviors of PET via the polymerization process. The structure and property of the APET were characterized by DSC and DMA. The results showed that the APET exhibits amorphism, transparency, higher glass‐transition temperature (Tg), and higher storage modulus than that of PET. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1653–1657, 2001 相似文献