Atom transfer radical polymerization of n‐butyl methacrylate in an aqueous dispersed system

Atom transfer radical polymerization of n‐butyl methacrylate (BMA) was conducted in an aqueous dispersed system with different kinds of copper complexes. The partitioning behavior of the copper complexes, including CuCl/4,4′‐di(5‐nonyl)‐2,2′‐bipydine (dNbpy), CuCl₂/dNbpy, CuCl/2,2′‐bipydine (bpy), CuCl₂/bpy, CuCl/bis(N,N′‐dimethylaminoethyl)ether (bde), and CuCl₂/bde between the monomer (BMA), and water was studied in detail with ultraviolet‐visible spectroscopy. The results show that with a less hydrophobic ligand, such as bpy or bde, most of the Cu(I) or the Cu(II) complexes migrated from the BMA phase to the aqueous phase, the atom transfer equilibrium was destroyed, and the polymerization was nearly not controlled; it converted to classical emulsion polymerization. As to the very hydrophobic ligand dNbpy, although the partitioning study of the copper complexes indicated that not all the copper species were restricted to the organic phase, the linear correlation between the molecular weight and the monomer conversion and the narrow polydispersities confirmed that the polymerization was still quite well controlled. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3175–3179, 2003     

碱液对储层损害实验评价研究

碱是钻井液中的处理剂之一,常用的有NaOH、Na2CO3和KOH等,通过选取苏北草舍泰州组、祝庄和茅山阜宁组的岩心进行碱液溶蚀试验和室内模拟碱流动评价实验得知,三种类型不同浓度的碱(KOH、NaOH和Na2CO3)对苏北草舍泰州组、祝庄和茅山阜宁组的岩心的碱溶失率都不高,三种碱3%KOH、5%NaOH和7%Na2CO3对草舍油田泰州组碱敏损害程度很小都为弱碱敏,综合看来,3%NaOH碱作为苏北油田钻井液碱处理剂比较理想。     

护色工艺对真空油炸脱水马铃薯片品质的影响

采用真空油炸前预处理技术，研究了护色工艺对真空油炸马铃薯片品质的影响。结果表明，马铃薯片经过第四组护色液配方（柠檬酸1‰，亚硫酸氢钠1‰，VC1．5‰）处理后，产品具有最佳的感官品质和色泽值，而且对其水分含量、水分活度和脂肪含量均无显著性影响。     

2-氯-5-氯甲基-1,3-噻唑提纯新方法

2-氯-5-氯甲基-1,3-噻唑(CCMT)是一种重要的农药中间体。介绍了以1-异硫氰酸基-2-氯-2-丙烯和氯气反应制备2-氯-5-氯甲基-1,3-噻唑的方法,并重点介绍了通过合成2-氯-5-氯甲基噻唑盐酸盐的方法进行产品提纯的新方法,产品含量大于99%,提纯收率95%。     

粉煤灰沸石合成及应用研究

对水热合成法、碱融法粉煤灰沸石合成工艺进行了探讨,得到了最佳合成参数.对Cr6 的去除实验表明,粉煤灰沸石在水处理领域将有广阔的应用前景.     

Surface modification of single‐walled carbon nanotubes with polyethylene via in situ Ziegler–Natta polymerization

Single‐walled carbon nanotubes (SWNTs) were modified with polyethylene (PE) prepared by in situ Ziegler–Natta polymerization. Because of the catalyst pretreated on the surface of the SWNTs, the ethylene was expected to polymerize there. Scanning electron microscopy images and solubility measurements showed that the surface of the SWNTs was covered with a PE layer, and a crosslink may have formed between the SWNTs and PE. When the SWNTs covered with a PE layer were mixed with commercialized PE by melt blending, the resulting composite had better mechanical properties than the composite from the SWNTs without a PE layer. The yield strength, the tensile strength and modulus, the strain at break, and the fracture energy of the modified‐SWNT/PE composites were improved by 25, 15.2, 25.4, 21, and 38% in comparison with those of the raw‐SWNT/PE composites. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3697–3700, 2004     

单组分聚氨酯乳液制备及其结构与性能研究

采用预聚合法,以聚酯二元醇(PEA)、甲苯二异氰酸酯(TDI)、二羟甲基丙酸(DMPA)为基本原料合成了分子链上带有亲水基团(-COOH)的聚氯酯预聚体。以特殊的水化方式制得聚酯型水性聚氨酯乳液。讨论了温度、-NCO-与-OH的物质的量之比(R)、亲水基团含量、合成工艺分别对材料力学性能、耐水性、玻璃化转变温度(Tg)等的影响。研究发现,采用前中和工艺、在高速搅拦下将预聚物加入到水中的水化方式,当R值为1．2,羧基含量为1．6％时,合成的聚酯型水性聚氨酯乳液具有较好的贮存稳定性,且涂膜的耐水性和力学性能良好。     

CaO–ZrO2 Solid Solution: A Highly Stable Catalyst for the Synthesis of Dimethyl Carbonate from Propylene Carbonate and Methanol

CaO–ZrO₂ prepared by co-precipitation showed to be a well-performed catalyst for the transesterification of propylene carbonate (PC) and methanol. The characterization by X-ray powered diffraction (XRD) and Raman spectroscopy indicated that CaO was doped into the lattice of ZrO₂ to form CaO–ZrO₂ solid solution. Such a solid solution was a strong solid base, which was proved by CO₂ temperature program desorption (CO₂-TPD). As a result, the catalyst showed high stability towards the transesterification of propylene carbonate and methanol into dimethyl carbonate with high PC conversion, especially being subjected to the continuous production of dimethyl carbonate at reactive distillation reactor for 250 h without any obvious loss of activity at the PC conversion of 95%.     

环氧树脂柔性固化剂研究综述

环氧树脂柔性固化剂种类众多，主要介绍改性脂肪族胺、脂环族胺、柔韧性酸酐、聚合物类环氧树脂柔性固化剂研究进展。认为对固化剂分子进行没计，开发合成柔性固化剂来增韧环氧树脂，可提高环氧固化物性能。     

Fabrication and amplification of Rhodamine B‐doped step‐index polymer optical fiber

A step‐index polymer optical fiber (SI POF) containing Rhodamine B in poly(methyl methacrylate) (PMMA) has been fabricated by a preform technique. Fluorescence of different fiber lengths were observed and discussed. A high gain (23 dB) for a SI POF with 60‐cm length, 400‐μm diameter was obtained. The Rhodamine B content of the doped SI POF is 5 ppm‐wt. The signal wavelength providing the highest gain for a 60 cm SI POF is around 630 nm, and the optimum fiber length is about 60 cm at 10 kW launched pump power. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 681–685, 2004