螯合-配位型硼酸酯偶联剂在PVC／CaCO3复合体系中的应用

报道了螯合-配位型硼酸酯偶联剂(OL- BAP)的性能、偶联作用机理及结构特点，研究OL-BAP用量对PVC／CaCO3体系力学性能的影响以及OL-BAP改性CaCO3对PVC／CaCO3复合体系力学性能的影响，并与铝酸酯偶联剂、钛酸酯偶联剂进行比较，得出OL-BAP的最佳用量为CaCO3的1％。OL-BAP是继铝酸酯偶联剂、钛酸酯偶联剂之后的又一类性能优异的水解稳定性良好的新型偶联剂。     

不同机理改性轻质CaCO3在油相中粘度行为的研究

由于碳酸钙(CaCO3)作为填充剂在塑料工业中的重要地位，及用不同方式改性的CaCO3对体系性能影响的争议．本文研究了用硬脂酸、铝酸酯偶联剂和钛酸酯偶联剂为改性剂的三种改性轻质CaCO，在石蜡油和邻苯二甲酸二丁酯(DBP)体系中粘度与填充量、温度、贮放时间等的关系，3种改性CaCO3在体系中的沉降性研究结果表明：3种改性轻质CaCO3在石蜡油和DBP体系中粘度行为的差别明显与其不同的改性机理有关．并作了简要描述。     

复合偶联剂改性纳米CaCO3工艺研究

采用正交试验法对钛酸酯和硬脂酸复合改性纳米CaCO3工艺进行了研究,探讨了改性剂用量、乳化温度、乳化时间和保温时间等因素对纳米CaCO3改性的影响,并优化出了最佳操作工艺条件：钛酸酯用量为纳米ca0。3的1,2％(质量分数)、硬脂酸用量为纳米CaCO3 4％(质量分数)、乳化温度70℃、乳化时间90min和保温时间80min。测定了改性纳米CaCO3和未改性纳米CaCO3的活化指数、吸油量、沉降体积以及在邻苯二甲酸二辛酯(DOP)中的粘度,结果表明钛酸酯和硬脂酸复合改性纳米CaCO3活化指数可达99．90％,吸油量降为15．23mL／100g,CaCO3／DOP糊粘度显著降低,亲油性得到显著提高。     

新型偶联剂改性碳酸钙及其在PVC中的应用

合成了新型两亲性钛酸酯偶联剂AEOT,用于改性超细CaCO3,系统研究了改性CaCO3在PVC型材中的应用,分析了改性CaCO3用量对PVC力学性能的影响。结果表明:用新型钛酸酯偶联剂改性的CaCO3可显著改善PVC复合材料的综合力学性能。     

动态DSC法研究UP树脂/CaCO3体系的固化工艺

采用差示扫描量热 (DSC)仪对UP树脂 (不饱和聚酯 ) /CaCO3 复合体系的固化过程进行动态研究 ,得出了体系在不同升温速率下固化过程中的DSC曲线 ,根据动态DSC曲线探讨了UP树脂 /CaCO3 复合体系分阶段变温固化新工艺。     

重质碳酸钙粉体改性研究

采用硬脂酸、钛酸酯、十二烷基苯磺酸钠、磷酸酯及其不同配比对CaCO3进行表面改性处理.通过对改性效果分析,讨论各改性剂的改性特点及最佳配比,寻找碳酸钙的改性最佳工艺.对碳酸钙表面改性,按活性大小改性剂的排序为:硬脂酸＞钛酸酯＞磷酸酯＞十二烷基苯磺酸钠,且复合改性剂比单一改性剂对碳酸钙表面改性效果明显.     

稀土钛偶联剂对CaC03改性及其在PE-LLD中的应用研究

采用万能试验机、转矩流变仪和旋转黏度计等研究了新型稀土钛偶联剂对不同粒径重质碳酸钙（CaCO3）的偶联处理及其对PE—LLD／CaCO3复合体系的力学性能和流变性能的影响。结果表明，稀土钛偶联剂改性的不同粒径CaCO3填充的复合体系的力学性能和流变性能得到很大改善；其中，稀土钛偶联剂处理粒径18μm重质CaCO3效果最好，当偶联剂含量为1．2％（质量分数，下同）时，复合体系的断裂伸长率、拉伸强度和拉伸弹性模量分别比未改性的提高了14．7％、12．5％和10．3％，而最大扭矩和平衡扭矩比未改性的分别降低了11．4％和9．6％；其改性效果均优于钛酸酯和铝酸酯偶联剂。实验表明稀土钛偶联剂处理的CaCO3在非极性液体石蜡中有较好的分散性和相容性。     

供水管用改性聚丙烯/纳米CaCO3复合材料的研究

以改性聚丙烯(PP)为基体、纳米CaCO3为填料，采用直接分散法及两步混炼工艺制备了供水管用改性PP／纳米CaCO3复合材料。阐述了纳米CaCO3的表面处理、钛酸酯偶联剂含量、纳米CaCO3含量及不同混合工艺对纳米复合材料性能的影响。同时对改性PP／纳米CaCO3复合材料及其供水管材的制备工艺进行了分析讨论，确定了改性PP／纳米CaCO3复合材料的配方及其成型工艺参数，并与国内外相关产品的性能进行了比较。     

改性纳米CaCO3/PVC复合材料的力学性能

采用钛酸酯偶联剂和PMMA接枝方法改性纳米碳酸钙,并采用熔融共混法制备了改性纳米CaCO3增韧PVC（CaCO3／PVC）复合材料,研究了复合材料的力学性能。对比于未处理纳米CaCO,和钛酸酯偶联剂处理纳米CaCO3,PMMA接枝聚合改性纳米CaCO3与基体的相容性最好,增韧PVC复合材料的拉伸强度得到较大幅度提高。     

纳米碳酸钙的表面改性

采用钛酸酯偶联剂对纳米碳酸钙进行表面改性,并对改性粉体进行了表征;钛酸酯偶联剂湿法改性纳米碳酸钙的最佳条件为:钛酸酯偶联剂的用量为3%,改性时间为1h,粉体浓度为20%,改性温度为80℃;改性后纳米碳酸钙粉体的吸油值为25.40g DOP/100g CaCO3,活化度为1,表明改性后的纳米碳酸钙已经由亲水性变为疏水性。     

Mechanics of a turbulent contact absorber

The operating conditions of a turbulent contact absorber (TCA) can be divided into four regimes. The characteristic behaviour of a TCA in each of the regimes is discussed. The condition below the flooding point is the usual operating regime. Correlations are developed to relate the pressure drop and the liquid holdup of a TCA by the operating variables. A terminal velocity model is developed to explain the flooding condition of a TCA. With this model, the hydrodynamic behavior of the TCA at the flooding point can be identified. The total pressure drop and the pressure drop across a single stage are distinguished to clarify the controversy whether the gas velocity can affect the pressure drop of a TCA. The total pressure drop of a TCA is composed of the pressure drop due to distributor loss at the entrance and the pressure drop of the bed itself. The pressure drop of a single stage bed of a TCA is independent of gas velocity.     

3,4,5-Trichloroaniline Nephrotoxicity in Vitro: Potential Role of Free Radicals and Renal Biotransformation

Chloroanilines are widely used in the manufacture of drugs, pesticides and industrial intermediates. Among the trichloroanilines, 3,4,5-trichloroaniline (TCA) is the most potent nephrotoxicant in vivo. The purpose of this study was to examine the nephrotoxic potential of TCA in vitro and to determine if renal biotransformation and/or free radicals contributed to TCA cytotoxicity using isolated renal cortical cells (IRCC) from male Fischer 344 rats as the animal model. IRCC (~4 million cells/mL; 3 mL) were incubated with TCA (0, 0.1, 0.25, 0.5 or 1.0 mM) for 60–120 min. In some experiments, IRCC were pretreated with an antioxidant or a cytochrome P450 (CYP), flavin monooxygenase (FMO), cyclooxygenase or peroxidase inhibitor prior to incubation with dimethyl sulfoxide (control) or TCA (0.5 mM) for 120 min. At 60 min, TCA did not induce cytotoxicity, but induced cytotoxicity as early as 90 min with 0.5 mM or higher TCA and at 120 min with 0.1 mM or higher TCA, as evidenced by increased lactate dehydrogenase (LDH) release. Pretreatment with the CYP inhibitor piperonyl butoxide, the cyclooxygenase inhibitor indomethacin or the peroxidase inhibitor mercaptosuccinate attenuated TCA cytotoxicity, while pretreatment with FMO inhibitors or the CYP inhibitor metyrapone had no effect on TCA nephrotoxicity. Pretreatment with an antioxidant (α-tocopherol, glutathione, ascorbate or N-acetyl-l-cysteine) also reduced or completely blocked TCA cytotoxicity. These results indicate that TCA is directly nephrotoxic to IRCC in a time and concentration dependent manner. Bioactivation of TCA to toxic metabolites by CYP, cyclooxygenase and/or peroxidase contributes to the mechanism of TCA nephrotoxicity. Lastly, free radicals play a role in TCA cytotoxicity, although the exact nature of the origin of these radicals remains to be determined.     

Thermo- and pH-sensitivity of aqueous poly(N-vinylpyrrolidone) solutions in the presence of organic acids

The phase transition in poly(N-vinylpyrrolidone) (PVP) aqueous solutions is shown to occur at heating upon addition of organic acids such as isobutyric, isovaleric, and, especially, trichloroacetic (TCA) ones. The cloud point temperature (T_c) of PVP solutions drops from 70 to 6 °C when the TCA concentration rises from 0.2 to 0.3 mol/l. A decrease in T_c is even more drastic when HCl is also added though HCl addition to the system without TCA does not result in phase separation. These phenomena are explained by the reversible coordination between the non-ionized form of TCA and PVP units via hydrogen bonding. An increase in the medium acidity depresses TCA dissociation, resulting in an increase in PVP-TCA associate concentration. Calculations based on the pK_a values of TCA confirm this suggestion. The similar behavior is observed with poly(N-vinylcaprolactam) systems. The amount of TCA bound to PVP has been determined by means of separation of the precipitate by centrifugation at temperatures above T_c and subsequent titration of TCA in the polymer with NaOH. It is shown that the precipitate contains one TCA molecule per 3-6 VP units, this value decreasing down to 1.25-2 upon HCl addition to the system.     

PVC-U/蒙脱土纳米复合管材的研制

以蒙脱土为主要原料，通过适宜的有机物插层剂对其改性研制了有机蒙脱土。利用聚氯乙烯(PVC)的亲油性，运用插层技术将PVC熔体插入有机蒙脱土层间，使蒙脱土片层剥离并以纳米尺寸分散在PVC相中。用上述技术研制了PVC—U／蒙脱土纳米复合管材，管材的性能达到国标规定的指标。采用红外光谱对蒙脱土结构进行了表征，用热重分析仪考察了复合材料的热性能。     

In vitro skin permeation of cubosomes containing triclosan

Monoolein (MO) cubosomes containing triclosan (TCA) were prepared by micronizing MO cubic phases containing TCA in a bath-type sonicator. Pluronic F127 was used as a dispersant and no cubosomes could be produced from monoolein alone in the absence of the dispersant. The maximum tolerable ratio of TCA to MO for the formation of cubic phase was 16:84 (w/w). According to TEM photos and size distributions, the sizes of cubosomes were hundreds of nanometers. Using hydroxypropyl-β-cyclodextrin as a solubilizer for TCA, the in vitro skin permeation of TCA loaded in cubosomes was investigated on a diffusion cell. Even though the concentrations of TCA were the same in the suspensions of cubosomes, the skin permeations were increased more when the ratios of TCA to MO were higher in the cubosomes. Moreover, the permeations were higher than those of TCA suspension in aqueous solution of ethanol or propylene glycol.     

Effect of a coupling agent on the electromagnetic and mechanical properties of carbon black/acrylonitrile–butadiene–styrene composites

Titanate coupling agent (TCA) is widely used as a plasticizer in filled polymer processes. In this study, the effect of TCA with different contents (2 and 10 wt %) on the electrical conductivity, wave absorption, and mechanical properties of carbon black (CB)/acrylonitrile–butadiene–styrene (ABS) composites were investigated. The results indicate that with the addition of 2 wt % TCA to the filled CB, the electrical conductivity of CB/ABS composites improved greatly, but its wave absorption performance was weakened. In contrast, the addition of 10 wt % TCA to the filled CB improved the microwave absorption performance of the CB/ABS composites but led to poor electrical conductivity. However, TCA, regardless of the contents of 2 or 10 wt %, greatly improved the mechanical properties of the composites. The probable reasons for this are discussed on the basis of the fracture morphology of the sample, a chemical band between the filling and resin, and the physical coating between the filling and TCA. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1839–1843, 2006     

Time-correlation analysis of nonstationary time series

This paper introduces a new graphical method of displaying the evolutionary correlation properties of nonstationary time series. The method, called time-correlation analysis (TCA), summarizes the local correlation properties with a smooth and monotone characterization function interpretable as the first-order autocorrelation coefficient. The TCA plot is constructed by plotting the discretized characterization function as time series. Issues concerning the range of the TCA plot are investigated in detail. Both simulated and real-data examples are given to demonstrate the application and interpretation of the method.     

Sorption and diffusion of volatile organic compounds in polydimethylsiloxane membranes

Sorption and diffusion of ethanol, 1,1,1-trichloroethane (TCA), and trichloroethylene (TCE) were investigated in polydimethylsiloxane (PDMS) membranes using a gravimetric technique. The thermodynamic equilibrium and kinetic properties were evaluated at temperatures of 25, 100, and 150°C. The sorption isotherms for TCA and TCE can be correlated well using the Flory-Huggins model. However, a three parameter Koningsveld-Kleinjtens variation to the Flory-Huggins equation is required for correlation of the ethanol isotherm. The solubility coefficients of TCA and TCE increase with activity, but it remains almost constant for ethanol. The calculated sorption energies reveal high positive heat of mixing for ethanol. TCA and TCE sorption in PDMS decreases strongly with temperature as opposed to ethanol. Clustering function analysis is used to explain the anomalous ethanol sorption and diffusion behavior in PDMS. TCA and TCE diffusivities do not exhibit large variations with volatile organic compound activity. However, ethanol demonstrates a maxima in its diffusivity at activities where it has minimum clustering tendencies. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67: 165–175, 1998     

杂交瘤细胞流加培养中葡萄糖和谷氨酰胺的代谢控制

对底物限制的流加培养中杂交瘤细胞HB 58的生长、代谢和单抗生成进行了研究。葡萄糖或 谷氨酰胺限制引起比生长速率下降。葡萄糖限制时,乳酸生成减少,细胞对葡萄糖的得率增 加,乳酸对葡萄糖的得率降低,说明葡萄糖更多地参与三羧酸循环。谷氨酰胺限制时,氨和丙氨酸生成减少,细胞和氨对谷氨酰胺的得率增加,丙氨酸对谷氨酰胺的得率减小,说明谷氨酰胺更多地参与脱氢反应,其有效利用率得到提高。