DYE-SENSITIZED PHOTOPOLYMERIZATION OF METHYL METHACRYLATE INITIATED BY COUMARIN DYE/IODONIUM SALT SYSTEM*

The photosensitive initiating system composed of 7-diethylamino-3-(2'-benzimidazolyl)coumarindye (DEDC) and diphenyliodonium hexafluorophosphate (DIHP) which act as the sensitizer and the initiatorrespectively, can be used to initiate the polymerization of methyl methacrylate (MMA). The results showedthat when exposed to visible light, coumarin dye/iodonium salt undergoes quick electron transfer from DEDCto DIHP and free radicals are produced. The visible light photoinduced reaction between DEDC and DIHP ismainly through the excited singlet state of DEDC and thus it is a little sensitive to O_2. The influence ofconcentration of DEDC, DIHP and MMA on the rate of photopolymerization of MMA was also investigated.     

无机盐对非离子表面活性剂从水相到油相传质的影响研究

采用同位素示踪原子法研究了非离子表面活性剂在无机盐存在下从水相到油相传质的规律,发现无机盐强烈地影响非离子表面活性剂Ａｐ型和Ｓｐ型的传质行为,而且因无机盐性质的不同,表面活性剂结构的差异,传质行为亦会有很大的不同。中外,利用此技术研究解决了连续定量测定微量表活剂的问题,为系统研究表面传质问题开辟了一个新方法。     

Conductivity of Phosphoric Acid, Sodium, Potassium, and Ammonium Phosphates in Dilute Aqueous Solutions from 278.15 K to 308.15 K

Precise conductivity measurements on aqueous solutions of phosphoric acid, sodium dihydrogen phosphate, potassium dihydrogen phosphate, ammonium dihydrogen phosphate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, diammonium hydrogen phosphate, sodium phosphate, and potassium phosphate were performed from 5 to 35°C. Data analysis was executed by the use of the Quint–Viallard equation for unsymmetrical electrolytes. Equations are given for the concentration dependence of electrolyte and single-ion conductivities at all temperatures.     

配合物[Ln(CH3COO)2(NO3)(bipy)]2的合成与晶体结构

合成了５种新型镧系四元混合阴离子配合物,用Ｘ射线四圆衍射仪测定了［Ｐｒ（ＣＨ３ＣＯＯ）２（ＮＯ３）（ｂｉｐｙ）］２的晶体结构,四个醋酸根呈两种配位方式,测定了铕和钆配合物的荧光和ＥＳＲ谱．     

主链含环三硅氮烷的聚硅氧烷的合成——环硅氮阴离子引发环硅氧烷开环聚合

在极性溶剂中合成了六苯基环三硅氮烷锂盐（Ｐ３ＮＬｉ） ．在促进剂的作用下,此锂盐成功地引发了环硅氧烷的开环聚合．通过对聚合物的含氮量、１Ｈ ＮＭＲ、２９Ｓｉ ＮＭＲ 谱的测试,结果证明所得到的聚合物中含有六苯基环三硅氮烷,并研究了聚合物的分子量（ＧＰＣ） 与特性粘数的关系．     

Quaternary ammonium salts as alkylating agents in the synthesis of tertiary phosphine oxides

A procedure was developed for the synthesis of tertiary phosphine oxides by alkylation of secondary phosphine oxides with quaternary ammonium salts. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 390–392, February, 1999     

Decomposition of Cyclohexyl-t-butyl-Dimethylammonium Tetraphenylborate: Synthesis and kinetics

A new compound cyclohexyl-t-butyldimethylammonium tetraphenylborate, [C₆H₁₁N(CH₃)₂(C(CH₃)₃)]BPh₄ has been prepared, and its decomposition mechanism was studied by TG. The IR spectra of the products of thermal decomposition were examined at every stage. Kinetic analysis for the first stage of thermal decomposition process was obtained by TG and DTG curves, and kinetic parameters were obtained from the analysis of the TG-DTG curves with integral and differential equations. The most probable kinetic function was suggested by comparison of kinetic parameters.This revised version was published online in November 2005 with corrections to the Cover Date.     

Role of the Acidic-basic Characters of Some Metal Oxides in the Pyrolysis of Ammonium Perchlorate

Six metal oxide samples were prepared by calcination of the corresponding precursors at 500°C for 5 h in air and were characterized by IR and XRD analyses. Their surface areas were calculated by means of the BET method. The acidities and basicities of these metal oxides were estimated thermogravimetrically by the method of adsorption of pyridine and formic acid as probe molecules. The pyrolyses of pure ammonium perchlorate (AP) and of AP mixed with (10% w/w) metal oxide were studied, in a dynamic atmosphere of N₂, by thermogravimetric analysis (TG) and derivative thermogravimetric analysis. A correlation was found between the catalytic activities of the metal oxides during the pyrolysis of AP, and their acidic-basic characters. The activation energies of the non-catalyzed and catalyzed pyrolysis of AP were calculated from the TG results via the Coats-Redfern equation. This revised version was published online in July 2006 with corrections to the Cover Date.     

Functional testing using rapid prototyped components and optical measurement

Rapid prototyping manufacturing methods such as stereo-lithography, fused deposition modelling, enable real parts to be produced very quickly from CAD models but because the parts are produced in materials which are different from the final component, these cannot readily be used for assessing structural integrity. Electronic speckle pattern interferometry (ESPI) enables full-field measurement of surface displacements, both static and dynamic to be made rapidly. This paper proposes the use of these two techniques together to enable the response of parts to static and dynamic loading to be assessed early on in the design process. It should be possible to make a qualitative assessment by observing the form of the deformation or vibration pattern produced and it may also be possible to make quantitative measurement by developing suitable scaling methods. Some initial experiments have been made looking at the vibration of flat plates and further proposed work is outlined.     

Vibrational Spectra and Structure of an Acid Tripotassium Disulfate Crystal

Infrared and polarized Raman spectra of a K₃H(SO₄)₂ crystal are experimentally obtained at a temperature of 92 K and at room temperature. The structural, spectral, and calorimetric measurements together confirm that the K₃H(SO₄)₂ crystal has a monoclinic syngony and contains the dimers SO₄ ^2–...O₃SOH^– as base units. The sulfate anions are hydrogen-bonded.