可降解磷酸酯聚合物的合成与应用研究进展

磷酸酯类聚合物在自然界中可以降解,是环境友好的化学品.其中,分子量高的聚磷酸酯近年来在医药、塑料助剂等方面有广泛应用,分子量相对较低的磷酸酯类聚合物在饲料、表面活性剂等方面很重要.按用途的不同,综述了可降解磷酸酯聚合物的合成与应用近况.     

Mechanical analysis on rocket propellants

The mechanical properties of solid rocket propellants are very important for good functioning of rocket motors. During use and storage the mechanical properties of rocket propellants are changing, due to chemical and mechanical influences such as thermal reactions, oxidation reactions or vibrations. These influences can result in malfunctioning, leading to an unwanted explosion of the rocket motor. Most of modern rocket propellants consist of a polymer matrix (i.e. HTPB) filled with a crystalline material (i.e. AP, AN). However, the more conventional double base propellants consist of a solid gel matrix with additives, such as stabilizers. Both materials show a mechanical behaviour, quite similar to that of general polymers. To describe the material behaviour of both propellants a linear visco-elastic theory is often used to describe the mechanical behaviour for small deformations. Because the time-temperature dependency is also valid for these materials a mastercurve can be constituted. With this mastercurve the response properties (stiffness) under extreme conditions can be determined. At TNO-PML a mastercurve of a double base propellant was constituted using dynamical mechanical analysis (DMA) and compared with a mastercurve reduced from conventional (static) stress relaxation tests. The mechanical properties of this double base propellant determined by DMA were compared with conventional (quasi-static) tensile test results. This revised version was published online in July 2006 with corrections to the Cover Date.     

聚（2,5—二甲氧基对苯乙炔）的可溶性前聚物合成及表征

研究了合成聚（２，４－二甲氧基对苯乙炔）的有机可溶性前聚物的反应条件与单体转化率和前聚物产率的关系。实验结果表明：ＮａＯＨ是聚合反应的有效引发剂，适宜的反应条件为：单体与ＮａＯＨ摩尔比为１：１，单体浓度０．０５－０．２ｍｏｌ／Ｌ，聚合时间２ｈ，温度低５℃，正己烷、石油醚作为有机提取剂可有效提高前聚物产率。用ＩＲ、ＵＶ－Ｖｉｓ＇＾ＨＮＭＲ，ＴＧＡ和 ＤＳＣ对前聚物进行了表征。     

Hydrothermal Synthesis and Crystal Structure of a Novel Isophthalate-bridged Copper(II) Polymer with Two-dimensional Network Structure: [Cu_2(phen)(ipt)_2]_(2n)·nH_2O (ipt = isophthalate, phen = 1,10-phenanthroline)

1 INTRODUCTION donor due to the presence of the protonated carboxyl group; (d) it can form short bridges via one car- Coordination polymers are of great interest due to boxylato end or long bridges via the benzene ring[7]. their physical properties and potential applications in We believe that coordination functionality of isoph- functional materials[1~3]. Aromatic polycarboxylic acids thalate can lead to interesting structures. In this com- such as 1,2,4,5-benzenetetracarboxylic acid[4],…     

甲酰胺对有序介孔二氧化硅形貌的影响

At room temperature and in acidic solution, ordered mesoporous silicas with particular morphology were synthesized using cetylpyridinium chloride as the template and formamide as the cosolvent. Scanning electron microscope (SEM), small angle X-ray diffraction (SXRD), and nitrogen adsorption techniques were used to characterize the as-synthesized and calcined samples. Results showed that the samples had hexagonal mesostructure analogous to MCM-41 and relatively narrow pore-size distributions (BJH). Besides, BET surface areas of the samples were in the range of 1 000～1 250 m²·g^-1 and high total pore volumes were up to 1.367 cm³·g^-1. Addition of formamide affected obviously mesostructures and the morphology of the mesoporous silica. Furthermore, with the increase of the concentration of formamide, the unit-cell constant decreased and particle shape changed from gyroids to fibers.     

可溶导电聚苯胺的合成及其性能研究

以十二烷基苯磺酸（ＤＢＳＡ）为乳化剂和掺杂剂，采用水一油二相乳液聚合物方法对苯胺进行合成，制备出高溶解性和高电导率的ＰＡｎ，通过ｘ－射线，电镜分析和热重分析对产物的结构和性能进行了研究。结果表明，该法合成的导电性ＰＡｎ具有较高的特性粘度，溶解性，耐热性及结晶度，与非极性溶剂－表面活性剂－水三相体系聚合产物结果相似，透射电镜显示水乳液聚合产物呈较规则的纤维状取向排列。     

高分子基PTC复合材料的研究及其应用

本文概述了高分子基PTC复合材料最近的研究动态，阐述了其作为热敏材料在自控温加热系统和过流保护元件方面的广泛应用。     

Photografting of vinyl polymers onto ultrafine inorganic particles: Photopolymerization of vinyl monomers initiated by AZO groups introduced onto these surfaces

The photografting of polymers onto ultrafine inorganic particles, such as silica and titanium oxide, initiated by azo groups introduced onto these surfaces was investigated. The introduction of azo groups onto the particles was achieved by the reaction of 4,4′-azobis(4-cyanopentanoic acid) with surface isocyanate groups, which were introduced by the treatment with tolylene 2,4-diisocyanate. It was found that the photopolymerization of vinyl monomers, such as methyl methacrylate (MMA), styrene, and N-vinylcarbazole, is initiated by ultrafine particles having azo groups. The corresponding polymers were effectively grafted onto these surfaces through the propagation of the polymer from the surface radicals formed by the photodecomposition of the azo groups: e.g., the percentage of grafting of PMMA and polystyrene onto silica was reached to 112 and 176%, respectively. The percentage of grafting onto silica in the graft polymerization initiated by photodecomposition of surface azo groups was much larger than that initiated by thermal decomposition. Polymer-grafted ultrafine particles thus obtained gave a stable colloidal dispersion in good solvents for the grafted chain. © 1994 John Wiley & Sons, Inc.     

核磁共振法测定高聚物的结构—核磁共振二维谱

介绍了核磁共振(NMR)波谱,尤其是核磁共振二维谱(2D NMR)在最近几年内的进展。内容包括怎样用NMR测定高聚物的序列分布、共聚物结构、聚合物的混溶性、聚合物液晶的取向度、分子量、短链度和长链支化度、凝聚态高聚物的多相结构等。     

Ce(H_2O)_7Al(OH)_6Mo_6O_(18)·4H_2O: A New One-dimensional Zigzag Chainlike Structure of Anderson Cluster Linked by Cerium Ions

IntroductionPolyoxometalates(POMs),as an important familyof metal oxides,have been receiving considerable at-tention in solid-state materials chemistry due to their di-verse topological properties and potential applications incatalysis,photochemistry,electrochemistry,medicineand magnetism[1,2].Recently,one of the intriguingfields in the polyoxometalate chemistry is to find somenovel subunits and then connect them into one-,two-,even three-dimensional(1-,2-,even3-D)extendednetworks,either thro…