固相法聚烯烃氯化基本现象研究

以固相法高氯化聚乙烯（ＨＣＰＥ）的制备为例，研究固相法聚烯烃氯化中的基本现象。结果表明：固相法聚烯烃氯化中存在着明显的粘结、烧结、局部过热和密度增高等现象，温度是影响粘结和烧结的主要因素，粘结使氯化速度降低、氯分布均匀性变差，局部过热导致晶区熔融参与氯化，原料、氯含量和粘结决定了产物的密度。     

利用低温氯化渣制备发泡多孔陶瓷材料研究

为了提高低温氯化渣的烧结成瓷效果,以低温氯化渣为主要原料,结合剂选择铝酸盐水泥和白泥,烧结促进剂选择氧化铝微粉,采用半干法打击成型,研究了白泥、铝酸盐水泥和Al2O3微粉对低温氯化渣烧结性能的影响,试验表明:添加白泥、铝酸盐水泥和Al2O3微粉有利于低温氯化渣的烧结,可以提高低温氯化渣的烧结强度.选择木屑作为造孔剂,采用浇注成型方法制备发泡多孔陶瓷材料,试验表明:煅烧温度在1050℃,白泥添加量为30％,铝酸盐水泥添加量为5％,造孔剂添加量为7％,制得的低温氯化渣多孔陶瓷材料的吸水率为30％,强度为5 MPa,可以满足建筑墙体材料的使用要求.     

丙烯酸改性氯化聚丙烯的合成和粘结性能的研究

氯化聚丙烯是聚丙烯的氯化改性产物，通过改性，其硬度、耐磨性、耐酸性、耐盐水性能均比聚丙烯好，耐热、耐老化性也优于聚丙烯。但其性能尤其是粘结性能还不能满足其在胶粘剂等方面的需要，为了进一步提高氯化聚丙烯的粘结性能，拓宽其应用领域，需对氯化聚丙烯改性。接枝共聚法是一种很好的化学改性方法。为此，华南理工大学化工学院化工所的傅和青等以丙烯酸作为接枝单体，以过氧化苯甲酰为引发剂，以甲苯为溶剂，采用液相接枝共聚法，将丙烯酸单体接枝到氯化聚丙烯大分子链上，得到丙烯酸改性氯化聚丙烯产物。     

用凝聚法制备粉末丁腈橡胶

以非交联或交联剂的丁腈－４０胶浆为原料，用正凝聚法使橡胶杨粉得到粉末橡胶淤浆，再加入隔离剂防粘结，经过滤，洗洗，过滤，干燥而掉得粒烃大于１．２５ｍｍ，橡胶含量大于９０％的粉末丁腈橡胶。研究了凝聚方式，隔离剂，凝聚剂，胶浆稳定性，凝聚条件，凝聚设备的结构等对成粉率的影响，成粉率达９０％以上，并所制产品与国外同类产品进行了比较。     

温度控制方式对气—固相氯化反应的影响

采用搅拌式固相法制备氯化等规聚丙烯（CIPP）,讨论了不同的温度控制方式对等规聚丙烯氯化反应的影响。结果表明,在恒定的温度条件下,100～103℃是较好的反应温度,温度过低产物的氯分布不均匀,温度过高容易发生脱氯化氢现象。在热处理方式下,由于气-固相反应特有的烧结和粘结影响严重,不利于氯化反应的进行。逐步长温的控温方式是制备CIPP的最佳温度控制方式。     

橡胶隔离剂C-66的制备及性能研究

介绍新型橡胶隔离剂C-66的制备工艺及其对胶片的隔离效果。结果表明：隔离剂C-66常温下易分散于水相，悬浮稳定性优，消泡速度快，制备工艺简单；浸泡隔离剂C-66的胶片风干速度快，附着物分散均匀，叠放胶片无粘连现象，隔离效果良好；隔离剂C-66对胶料性能无不良影响。     

丁苯胶乳的包覆凝聚粉末化

以自制的阴离子表面活性剂（Ｃｏｒｏｎ树脂）为包覆剂，对丁苯胶乳粒子进行包覆，通过凝聚法制得粒径不大于１ｍｍ、外观白色、颗粒均匀的粉末丁苯橡胶。研究了Ｃｏｒｏｎ树脂用量、隔离剂用量、凝聚温度、搅拌速度及干燥条件对粉末粒径及抗粘结性能的影响，找到了最佳的工艺条件。借助透射电镜观察了粉末粒子的形态，提出了粉末化机理。     

改性粉末隔离剂的应用研究

研究改性粉末隔离剂的应用,并与现用隔离剂进行对比。结果表明:改性粉末隔离剂具有很好的溶解稳定性,隔离效果好,凝固后无结块现象,对胶料性能无不利影响,可以满足正常生产需求;当改性粉末隔离剂质量分数为0. 035时,胶料的综合性能较好。     

一种新型牙本质表面处理剂

本研究对于七种牙本质表面预处理剂进行了比较、其中自制的柠檬酸-NPG牙本质预处理剂获得较好的粘结强度,且对牙髓的刺激可减轻。     

氯化苯生产中的几个技术问题

分析了氯化苯生产中产生铁环烧结与黑料、低温下二氯苯生成量过多及氯化液中黑色絮状沉淀物等现象的原因，并提出了相应的技术处理措施。     

表面活性剂对丁二酸冷却结晶中聚结的抑制

借助聚焦光束反射测量仪(FBRM)和颗粒录影显微镜(PVM)对丁二酸冷却结晶过程中的聚结现象进行研究,通过加晶种实验和不加晶种实验初步推断大小颗粒的共存及颗粒间的相互结合力是形成聚结需要考虑的两个因素。在此基础上,将3种类型的表面活性剂十六烷基三甲基溴化铵(CTAB)、十二烷基苯磺酸钠(SDBS)和吐温80(Tween80)加入到丁二酸冷却结晶系统,考察了表面活性剂对结晶过程中颗粒聚结的抑制作用。晶体形貌变化表明,所选的表面活性剂均能吸附于晶体表面,且可大大降低聚结,可推测表面吸附产生的机械隔离能够降低晶体间的相互结合力,并促使结晶产品的粒度更为均匀。这一研究证明添加表面活性剂可降低结晶过程的聚结程度。     

Granular flow and dielectrophoresis: The effect of electrostatic forces on adhesion and flow of dielectric granular materials

Electrostatic forces can significantly alter flow properties of granular materials and can adversely affect many industrial particulate processes in unpredictable ways. We investigate here the effect of higher order dielectric electrostatic forces, which are created by non-uniform electric fields, on the agglomeration, adhesion and flow of several granular materials, including pharmaceutical powders. We find that materials can adhere consistently and reproducibly to a metallic rod in a sufficiently strong electric field, which can be produced by either a DC source or tribocharged surfaces. These results provide a simple way to characterize material susceptibility to electrostatic agglomeration. The effect of applied non-uniform fields on the flow of grains falling from a cylindrical hopper is studied and found to significantly reduce the particle flow rate. The effects of humidity, particle size, coatings, and the grounding of equipment are also tested. Finally, contrary to common intuition, we find that grounding a metallic surface can actually exacerbate particle adhesion and agglomeration.     

ALKALI-INDUCED AGGLOMERATION OF SOLID PARTICLES IN COAL COMBUSTORS AND GASIFIERS

The effect of alkali adsorption on the agglomeration of particles of bauxite, kaolinite, emathlite, lime and two types of coal ash is studied. An agglomeration (adhesion) temperature is defined which characterizes the adhesion propensity of particles. An experimental technique is developed to measure this agglomeration point in situ and without sample quenching or removal. The effect of alkali adsorption on the agglomeration characteristics of the substrates is determined. The agglomeration temperature for all substrates decreases a:, alkali content increases. At low loadings the alkali adsorption enhances particle agglomeration by forming new compounds of lower melting points. At high concentrations, the agglomeration point of all substrates approaches the melting point of condensing alkali. Under these conditions, adhesion and agglomeration are caused by a layer of molten alkali which covers the exterior of the particles.     

Agglomeration kinetics of coking coal particles during the softening phase

Agglomeration kinetics under thermal conditions describe the structure and formation of larger bodies, termed agglomerates from coal particles, as a preliminary phase of semi-coke formation. Knowledge on particle adhesion characteristics are of particular importance for determining the strength as well as the structure of the agglomerates. Several adhesive forces acting during the adhesion mechanism may be roughly subdivided into bonding with and bonding without material bridges. The purpose of the present work was to investigate the adhesion mechanism; the formation and growth in time of the bonding neck between two particles, as well as the change of functional correlation with other parameters, i.e. temperature and coal quality. Experimental investigation of the kinetics of agglomeration was carried out using apparatus in which a coal layer was heated by radiation in an atmosphere of flowing nitrogen. Camera recordings allowed quantitative assessment of the growth of the bonding neck with time, and additionally the dependence of the parameters on temperature and coal quality could be determined. The evaluation of the tests yielded clear indications supporting the assumption that increased adhesion of two viscous spheres under the effect of surface tension can be used as a physico-chemical model for the agglomeration of two coal particles under thermal conditions.     

上浆剂对CF/EP界面粘结的影响

本文通过单纤维碎裂法，分别对未上浆及不同上浆剂处理的碳纤维与基体的界面粘结性进行表征。结果表明，不同上浆剂对界面粘结的影响不同。含活性基团较多的上浆剂可改善界面粘结，而含活性基团较少的上浆剂反而会使其减弱。     

乳胶粒子用附聚剂的制备及应用

采用丙烯酸(AA)、丙烯酸丁酯(BA)混合单体通过乳液聚合方法合成附聚剂,用于聚丁二烯胶乳(PBL)的附聚.研究了附聚时间、附聚剂组成、附聚剂加入量、附聚剂的粒子尺寸等因素对聚丁二烯(PB)胶乳粒径大小的影响.结果表明:附聚时间为40～60 min时,附聚过程基本完成;当BA/AA质量比为80/20时,附聚效果最好;附聚剂在PBL中加入量占PBL总质量的8.3％时,附聚效果明显;PBL平均粒径由原来的96nm附聚到了240～260 nm,粒径得到了明显的增长,合成的附聚剂有良好的附聚效果.     

Silver nanoparticle deposition on hydrophilic multilayer film surface and its effect on antimicrobial activity

Silver nanoparticles were deposited on the surface of the external polyamide 6 (PA6) layer of a multilayer film, by spraying and ultrasound‐assisted methods. The effect of silver nanoparticles content and deposition method on the mechanical and optical properties of the multilayered films as well as the efficiency of silver ion release and their fungicidal characteristics were evaluated. Itaconic (IA) and Maleic anhydride (MA) were used as adhesion promoter agents for preventing the agglomeration of the silver nanoparticles and for improving the adhesion to the PA6 polymer surface. With IA, a homogeneous distribution of silver nanoparticles on the PA6 surface was achieved. The silver ion release and biocide effect of the multilayered films was found to be dependent on the anhydride type and on the deposition method used. The multilayer films with a layer of PA6‐silver nanocomposite demonstrated good fungicidal activity, specifically against fungus Aspergillius niger. The observed results could be applied in the design of industrial films for packaging. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

磷石膏流化分解过程颗粒的黏附特性

磷石膏热分解制硫酸联产水泥过程中在回转窑部分很容易由于颗粒的团聚和壁面黏附,造成管道堵塞,这样会严重影响磷石膏热分解制硫酸联产水泥的工艺运行.经过对比流态化分解磷石膏后的结垢物和流化粉末的X射线荧光光谱、X射线衍射和扫描式电子显微镜分析研究磷石膏热分解过程中的黏附变化.结果表明,结垢物中的Si、Al等矿物质元素明显高于流化粉末,说明主要的黏土性矿物质杂质在壁面黏附富集;随着反应的进行,CaO的含量的增加会较为明显的降低颗粒的黏附程度.因此对于磷石膏粉体,SiO2、Al2O3等杂质不仅影响磷石膏的分解效率,还严重影响其流化过程中的团聚黏附.     

喷嘴结构改进及其液体射流过程颗粒团聚研究

在重质原料液的射流阶段降低反应温度会导致液体呈现不同的黏度,促使颗粒聚集形成不同尺寸的团聚结构,阻碍了原料液的热量传递,减缓了裂化反应的速率,颗粒团聚是流体焦化反应工艺面临的一个重要而又具有挑战性的问题。选用水-沙系统模拟热态沥青-焦炭系统,利用气罩装置改进喷嘴结构,基于电导信号法测量多黏度液体射流过程的电导信号随时间的变化规律,研究不同条件下流化床内颗粒团聚过程。研究结果表明：多孔气罩装置可以为喷嘴射流创造理想的稀相环境,避免了液滴在射流空腔以及交换区域的聚集和压缩;液体射流在床层扩散过程中可以观察到不同的流化阶段,即颗粒润湿阶段、团聚形成阶段、团聚隔离阶段;较高的气液比可以有效地阻止颗粒团聚,相比于较低的流化气速,较高的气速条件允许高黏度糖水溶液参与液体射流。本研究为多黏度液体射流过程颗粒团聚现象的在线监测提供了理论研究基础,确保了流化床内射流液滴与颗粒表面的良好接触。