PREPARATION OF BISPHENOL A EPOXY RESIN WATERBORNE DISPERSIONS BY THE PHASE INVERSION EMULSIFICATION TECHNIQUE*

The phase inversion emulsification technique (PIET) is an effective physical method for preparing waterbornedispersions of polymer resins. Some results concerning the preparation of bisphenol A epoxy resin waterborne dispersions byPIET in our laboratory were summarized. Electrical properties, rheological behavior and morphological evolution duringphase inversion progress were systematically characterized. The effects of the emulsifier concentration and emulsificationtemperature on phase inversion progress and the structural features of the waterborne particles were studied as well. Thedeformation and break up of water drops in a shear field were analyzed in terms of micro-rheology, while the interaction andcoalescence dynamics of water drops were discussed in terms of DLVO theory and Smoluchowski effective collision theory,respectively. Based on the experimental results and theoretical analysis, a physical model of phase inversion progress wassuggested, by which the effects of the parameters on phase inversion progress and the structural features of the waterborneparticles were interpreted and predicted.     

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.     

相反转乳化技术制备环氧树脂交联多孔微球

多孔微球在分离吸附、催化、涂料印刷等多方面具有潜在应用价值 .最近研究表明 ,当微孔孔径在 2 0 0～ 80 0ｎｍ范围时 ,由于强烈的光散射作用 ,多孔微球可以作为遮光剂使用[1] .Ｏｋｕｂｏ等用酸碱逐步处理法制备了一些共聚物的亚微米级多孔球[2～ 4] .Ｏｋｕｂｏ又用动态溶胀种子聚合法制备了微米级的聚合物微球 ,用类似的方法得到了多孔结构[5,6] .但这种方法涉及了许多烦琐过程并且产生了很多副产物需要处理 ,使得其费时费力而且成本相当高 .Ｓｃｈｌａｒｂ等发展了一种新的制备方法 ,在乳液聚合过程中引入有机溶剂 ,在实验后期除掉有机…     

HYDRODYNAMIC AND THERMODYNAMIC EFFECTS IN PHASE INVERSION EMULSIFICATION PROCESS OF EPOXY RESIN IN WATER

The mechanism of phase inversion emulsification process （PIE） was studied for waterborne dispersion of highly viscous epoxy resin using non-ionic polymeric surfactants. Drop deformation and breakup, rheological properties, conductivity, and particle size measurements reveal the micro-structural transition amid emulsification. It is revealed that strong flow causes water drop to burst with the formation of droplets and huge interface. Phase inversion corresponds to an abrupt rheological transition from a type of viscous melt with weak elasticity to a highly elastic type of aqueous gel. This implies that the phase inversion equivalent to a curvature inversion. Based on this, a geometric model is postulated to correlate process variables to the particle size. The coverage and conformation of the surfactant plays key role for the particle size of the final emulsion. The interactions of thermodynamic and hydrodynamic effects are also discussed. It is concluded that the thermodynamics control the PIE while the hydrodynamics drives the creation of interface and involves every step of PIE.     

不完全相反转发展过程的流变行为

以动态应力流变仪ＤＳＲ（ＤｙｎａｍｉｃＳｔｒｅｓＲｈｅｏｍｅｔｅｒ）对双酚Ａ型环氧树脂在低乳化剂浓度（２３３ｗｔ％）下的相反转乳化过程进行了稳态应力扫描及动态频率扫描实验．实验结果表明,体系在相反转点前表现为牛顿流体行为,粘度几乎不变;相反转点时,体系粘度增加幅度很小,体系的有关动态流变参数（剪切储能模量、损耗模量和复数粘度）均出现极小值,将此归于局部连续水相的润滑作用;进一步加水,体系的动态流变量增加,意味着相反转在相反转点后仍在继续进行．所以,体系在低乳化剂浓度时,发生了不完全相反转．     

DETERMINATION OF PHASE INVERSION POINT IN THE EMULSIFICATION OF POLYMERS

Polymer Physics Laboratory, Institute of Chemistry,The Chinese Academy of Sciences, Beijing 100080, China     

高分子水基微粒形态与界面膜性质的关系

高分子水基微粒形态与界面膜性质的关系杨振忠赵得禄许元泽徐懋（中国科学院化学研究所高分子物理开放实验室北京１０００８０）关键词高分子树脂，相反转，水基微粒，界面膜相反转技术是制备高分子树脂微粒化水基化体系的新方法［１］，正成为高分子技术的一个热门方向...     

相反转技术制备环氧树脂水基体系——相反转过程的流变行为研究

对高乳化剂浓度下的相反转发展过程的流变行为进行了应力扫描、动态频率扫描实验表征．结果表明，乳化剂浓度较高时，体系发生完全相反转；体系在相反转点前为Ｗ／Ｏ结构，其粘度几乎不随剪切应力的改变而改变，表现为牛顿流体行为；体系在相反转点后为Ｏ／Ｗ结构，具有很高的粘弹性，并且在较高剪切应力下表现为典型的假塑性．这是由于高分子水基微粒间通过其表面覆盖的表面活性剂与水形成氢键而产生了一种静态结构，此结构在较高剪切应力作用下破坏而导致假塑性．     

水性聚氨酯乳化过程中相转变的研究

本文合成了单官能团小分子物质封端的脂肪族水性聚氨酯预聚物 ,通过考察预聚物加水乳化过程中粘度及电导率的变化 ,研究了其相转变行为 .实验结果表明 ,随着软段分子量升高 ,体系的相转变点后延 ;聚酯体系的相转变比聚醚体系的相转变发生得早 ;[NCO]/ [OH]值越接近 1,体系的粘度就越高 ,相转变发生所需的水含量也越高 ;羧基含量及中和度也会对分散体系的相转变产生影响 .通过选择合适的条件 ,可以实现对乳化过程的优化     

STUDY ON THE EPOXY RESIN TOUGHENED BY HYDROXY-TERMINATED BUTADIENE-ACRYLONITRILE COPOLYMER

Toughened epoxy resin with excellent properties was obtained by adding organic acid anhydride curing agent and hydroxy-terminated butadiene-acrylonitrile copolymer (HTBN), which is cheaper than CTBN. The anhydride reacts with both epoxy groups on epoxy resin and hydroxyl groups on HTBN. As a result the soft long chains of HTBN and the rigid chain of epoxy resin form one network, giving the resin toughness. Two-phase structure of the toughened resin was observed by SEM and TEM.     

双酚A型环氧树脂多孔微球

双酚Ａ型环氧树脂多孔微球杨振忠许元泽俞浩赵得禄（中国科学院化学研究所高分子物理开放实验室北京１０００８０）关键词多孔微球，双酚Ａ环氧树脂，相反转技术微米级高分子多孔微球在生物医学、电子、印刷、信息业等方面具有重要作用．然而，通常的乳液聚合，悬浮聚合...     

EPOXY RESIN TOUGHENED BY THERMOPLASTICS

Two kinds of tough ductile heatresisting thermoplastic, namely bisphenol A polysulfone (PSF) and polyethersulfone (PES) were used to toughen thermoset epoxy resin. A systematic study on the relationship between the molecular weight and the terminal group of the thermoplastic modifier and the fracture toughness of the modified resin was carried out. The morphology of PSF modified epoxy resin was surveyed. With the same kind of PSF the structure of the epoxy resin and the toughening effect of PSF was also investigated. The fractography of PSF, particle modified epoxy was examined in detail with SEM. The contribution of every possible energy absorption process has been discussed. Crack pinning mechanism seems to be the most important toughening mechanism for tough ductile thermoplastic PSF particle modified epoxy system.     

环氧树脂微粒化水基化体系

本文系统介绍了环氧树脂微粒化水基化体系的特点及用途，制备方法和反映体系特性的一些重要参数。     

二步法合成低分子量双酚A环氧

对二步法合成低分子量双酚A环氧的反应历程进行了分析,指出了降低环氧氯丙烷与双酚A克分子比的途径和方法。     

离聚体水基微乳液化的研究──聚苯醚离聚体微乳化过程的相反转

以乙酰磺酸为磺化剂制备了磺化度为３～１７ｍｏｌ％的磺化聚苯醚（ＳＰＰＯ）并中和成盐,在一定的温度和搅拌速度下,加水将ＳＰＰＯ乳化成水包油的稳定水基微乳液．用乳化过程中的体系的电导率、粘度和表面张力的变化表征了乳化相反转过程．另外还研究了溶剂的极性和离子含量对ＳＰＰＯ溶液可乳化性和乳化过程的影响．     

双酚A型环氧树脂水基化微粒分析

高分子树脂水基化微粒化就是使高分子树脂以微粒形式分散于水中,高分子乳液、悬浮液都属于此范畴．因其不含有机溶剂,且具有无环境污染及不易失火等优点,放这方面的研究正成为高分子技术的一个研究热点．通常的乳液聚合或悬浮聚合方法是从小分子单体到聚合物水基化体系的化学反应过程,一般只适于制备加聚物的水基化体系,而不适用于制备维聚物的水基化体系．本文提出的相反转技术是一种有效的制备高分子水基化体系的方法,它能将几乎所有的高分子树脂通过物理的乳化方法制成相应的水基化体系[1,2],大大拓宽了其制备范围．相反转[3。4]…     

离聚体水基微乳液化的研究——聚苯乙烯离聚体微乳化过程相反转的表征

以乙酰磺酸为磺化剂制备磺化度为３～１５ｍｏｌ％的磺化聚苯乙烯（ＳＰＳ）并中和成盐．在一定的温度和搅拌速率下，加水将ＳＰＳ乳化成水包油的稳定水基微乳液．用乳化过程中体系电导率和粘度的变化表征了乳化相反转过程．研究了溶剂的极性和离子含量对聚苯乙烯离聚体溶液可乳化性和乳化过程及乳液稳定性的影响．     

PREPARATION AND PROPERTIES OF EPOXY RESIN MODIFIED BY LIQUID CHLOROPRENE-HYDROXYETHYLMETHACRYLATE COPOLYMER

The epoxy resin modified by liquid chloroprene-hydroxyethylmethacrylate copolymer (CP-HEMA) is a new kind of structural adhesives with good mechanical properties. By changing its mole-cular structure, it may also have such desirable properties as retardation of combustion, enduringweather aging, inert oils and chemicals. A series of the thermosets of the epoxy resin modifiedby CP-HEMA used as a toughener were prepared. The effects of CP-HEMA content, catalyst con-tent and curing temperature on the mechanical properties of modified epoxy resin system were studied.The thermal weight-loss curves were examined. The two-phase morphology was observed and dis-cussed.     

MICRO-PHASE SAEPARATION IN EPOXY RESIN WATERBORNE PARTICLES DURING CURING PROCESS

Sub-micron sized phenolic epoxy resin waterborne particles were prepared by phase inversion emulsification. Micro-phase separation occurred during the curing process at high temperature. The as-prepared samples possessed one glass transition temperature （Tg） and two exothermal processes during DSC heating scannings. After being thermally treated above the exothermal peak temperature, they possessed two glass transition temperatures with the disappearance of exothermal peaks, whilst a core/shell structure was formed. This was likely related with the outward diffusion of reactive oligomers to the outer layer of particles.     

PREPARATION OF MICROGEL-EPOXY RESIN TWO-PHASE POLYMERS BY IN SITU POLYMERIZATION~*

Microgel-epoxy resin two-phase polymers were prepared by in situ copolymerization of ethylenic monomers with unsaturated polyesters. The choice of monomers and the effect of monomer concentration on microgel particle size were discussed. Agglomeration of particles played a significant role in the early stage of polymerization. The microgel dispersion in epoxy resin was stable after the finish of polymerization. Upon curing the particles remained well dispersed.