PROGRESS IN PHASE INVERSION EMULSIFICATION FOR EPOXY RESIN WATERBORNE DISPERSIONS

In this review, our recent work in phase inversion emulsification （PIE） for polymer （especially epoxy resin） waterborne dispersions is summarized. Based on experimental results about PIE process, the physical model is proposed which can guide the synthesis of the waterborne dispersions such as polymer/nanoparticle composite dispersion. In the presence of a latent curing catalyst, PIE can give a crosslinkable epoxy resin waterborne dispersion. The dispersions can form cured transparent coatings with some unique properties such as UV shielding. They are promising in functional coatings, waterborne resin matrices for composites, and sizing for high performance fibers.     

Thermodynamic simulation of four-component carnallite type systems

Summary The standard method ofPitzer for predicting the solubility isotherms of systems in which solid phases with a constant composition crystallize is applied to cases when mixed crystals are formed. The four-component carnallite type systems RbCl-CsCl-MgCl₂-H₂O, RbCl-KCl-MgCl₂-H₂O, and RbCl-RbBr-MgCl₂-MgBr₂-H₂O and the corresponding subsystems are thermodynamically simulated at 25°C. It is established that the solubility diagrams consist of crystallization regions of the simple saltsMX,MX, MgX ₂·6H₂O, and MgX₂·6H₂O and of the corresponding carnallite type double salts with the composition 1:1:6. A method of calculation of the integralGibbs energy of mixingG ^mix(s) of crystals formed in water-salt systems has been proposed. The results on the systems RbCl-KCl-H₂O, RbCl-RbBr-H₂O, and MgCl₂-MgBr₂-H₂O are compared with experimental data from the literature and with values calculated using various models.

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Thermodynamische Simulation von Vierkomponentensystemen des Carnallit-Types

Zusammenfassung DiePitzer-Methode zur Voraussage der Löslichkeitsisothermen in Mehrstoffsystemen, in welchen feste Phasen mit konstanter Zusammensetzung auskristallisieren, wurde auch für Fälle angewendet, bei denen sich Mischkristalle bilden. Die Vierstoffsysteme RbCl-CsCl-MgCl₂-H₂O, RbCl-KCl-MgCl₂-H₂O und RbCl-RbBr-MgCl₂-MgBr₂-H₂O, aus welchen Carnallit-Typ-Mischkristalle auskristallisieren, und die dazugehörigen Dreistoff-Randsysteme wurden bei 25°C simuliert. Man stellt fest, daß die Löslichkeitsdiagramme sowohl Kristallisationsbereiche der einfachen SalzeMX,M'X, MgX ₂·6H₂O und MgX ₂·6H₂O als auch der entsprechenden carnallitartigen Doppelsalze mit der Zuzammensetzung 1:1:6 umfassen. Eine Methode zur Berechnung derGibbs-EnergieG ^mix(s) für die in Wasser-Salz-Systemen gebildeten Mischkristalle wird vorgeschlagen. Die für die Systeme RbCl-KCl-H₂O, RbCl-RbBr-H₂O und MgCl₂-MgBr₂-H₂O erhaltenen Ergebnisse werden mit experimentellen Literaturdaten und Resultaten von Berechnungen aufgrund verschiedener Modelle verglichen.

     

Synthesis of diethers derived from furoin by phase transfer catalysis under microwave irradiation

A series of new diethers were obtained by alkylation of furoin under microwave irradiation (MWI) in phase transfer catalysis (PTC) conditions. The products of alkyl halides were synthesized in good yields (>75%) within a few minutes, and the products of dihalides were synthesized in fair yields (about 45%). The yields are dramatically improved compared to conventional heating under the same conditions, in spite of similar profiles of rising in temperature.     

2,4,6—三氧—1,3,5,2—三氮磷杂环己烷衍生物的合成及其抗肿瘤活性

利用Ｎ，Ｎ－二（２－氯乙基）氨基磷酰二异氰酸酯和胺的加成反应，合成了２，４，６三氧－１，３，５，２三氮磷杂环己烷衍生物，它们的结构经＾１ＨＮＭＲ，ＩＲ和元素分析所证实。初步生物活性测试结果表明，部分化合物具有一定的抗肿瘤活性。     

乙烯-甲基丙烯酸共聚物离聚体在聚对苯二甲酸乙二酯中的相分离行为

聚对苯二甲酸乙二酯(PET)结晶速度很慢,通常加入成核剂来提高结晶速度。从专利文献来看,以离子聚合物为成核剂的例子也是很多的。离子聚合物与小分子成核剂的显著差别是:离子聚合物有一个很长的碳氢主链,其侧基为酸基,酸基被部分或全部地中和成盐。很明显,离子聚合物不象小分子成核剂那样能很好地分散在PET基体中,而是以独立的相存在。作为PET体系系列研究的继续,本文报道了离子聚合物Surlyn在PET中的相分离行为。     

溶剂浓度对PVDF相转换膜大孔结构的影响

提出决定大孔能否发展的初始分相点处溶剂浓度临界点的概念 ,认为初始分相点处较高的溶剂浓度有利于大孔的发展 ,溶剂浓度低于一定的界限后 ,大孔停止发展 ,转为海绵状结构 .实验考察了不同凝胶液组成下制得的PVDF中空膜的结构 ,建立了相应的传质模型 ,模拟不同制膜条件下初生态膜内的组成分布情况 ,根据初始分相点处溶剂浓度临界点的概念 ,预测膜的形态结构 .模拟结果与相应制膜条件下的电镜照片有很好的对应关系 ,证明了上述大孔形成机理的正确性 .     

钾镁氯化物(硫酸盐)与脲、水体系的溶度研究

报导了KCl-MgCl2-CO(NH2)2-H2O和K2SO4-MgSO4-CO（NH2）2-H2O两个四元体系在25℃时的溶度及其饱和溶液的折光率、密度，相应的溶度图和组成-折光率、组成-密度图．前一体系中形成3个三元化合物：MgCl2·4CO（NH2）2·2H2O、MgCl2·CO（NH2）2·4H2O和KCl·MgCl2·6H2O溶度盐份图由9支共饱线、4个四元无变点组成．四元体系的水量图、性质-组成图有类似的变化．后一体系中有2个异成份溶解化合物MgSO4·CO（NH2）2·2H2O和K2SO4·MgSO4·6H2O形成，溶度等温图由7支双饱溶度线、3个四元无变点组成．对两个体系相图的相似性和差异点进行了讨论．     

胶束形成的分形研究

提出了测定胶束质量分维的两种新方法即粘度法和GPC－LALLS联机法，随后从动态光散射数据计算了离子型胶束SDS的分维，这些实验数值之间能互相印证．建立了放束形成过程的Laplace分形理论，计算得分维D＝1.54（二级），作高级计算的分维D＝1.67与前面实测值基本相符，另外，从唯象理论角度，讨论了胶束的多重分形及其热力学行为，发现有两个相变点β_c＝-4和β_c＝-1．并认为这两个转折分别对应着单分子<=>分形胶束<=>经典胶束结构之间的转变．     

Neue Suboxid-Cluster [O5Ba18] in den Kristallstrukturen von Ba21M2O5 (M = Si,Ge)

Novel Suboxide Clusters [O₅Ba₁₈] in the Crystal Structures of Ba₂₁M₂O₅ (M = Si, Ge) The compounds Ba₂₁M₂O₅ (M = Si, Ge) crystallize in the cubic system with space group Fd3m, lattice constants 2 038.3(10) pm (Si), 2 039.8(9) pm (Ge) resp. and Z = 8. The crystal structure contains isolated Si/Ge atoms coordinated by barium atoms in an icosahedral arrangement. The oxygen atoms are situated in the centers of barium octahedra, four of which share common faces with an additional central octahedron. The novel clusters [O₅Ba₁₈] in principal are related to those in the crystal structures of the binary Cs/Rb suboxides.