自交联型丙烯酸酯共聚物乳液流变性能研究

本文用旋转粘度仪测定了自交联型丙烯酸酯共聚物乳液的流变性能。讨论了功能基结构单元的种类及用量对共聚物乳液流变性能的影响。研究结果表明:含甲基丙烯酸环氧丙酯体系、丁氧基甲基丙烯酰胺体系呈胀流型流体特征,而烃甲基丙烯酰胺体系呈胀流型和假塑性流体的特征。D—τ曲线服从τ=KD~n方程。     

甲基丙烯酸缩水甘油酯

甲基丙烯酸缩水甘油酯甲基丙烯酸缩水甘油酯（又名：甲基丙烯酸环氧丙酯）英文缩写为“ＧＭＡ”，分子式为：该产品做为交联单体主要应用于粉末涂料、热固性涂料、丙烯酸树脂和乳液等产品中。由于具有独特的化学结构、适中的化学性能，在涂料制作中只需加入少量，便可改变...     

甲基丙烯酸环氧丙酯接枝ABS共聚物及其制备方法

<正>公开号:CN102516464A公开日:2015-06-27申请人:贵州省复合改性聚合物材料工程技术研究中心摘要:本发明公开了一种甲基丙烯酸环氧丙酯接枝ABS共聚物及其制备方法,它是由ABS、甲基丙烯酸环氧丙酯、ABS高胶粉、过氧化物引发剂、接枝共聚体熔融制备而成。本发明采用甲基丙烯酸环氧丙酯对ABS进行接枝改性制备ABS     

纳米SiO2改性纯丙乳液的合成及性能研究

用纳米SiO2胶体、苯乙烯、甲基丙烯酸及其酯、反应性乳化剂、交联剂、偶联剂等成功地合成了常温自交联纯丙乳液，着重介绍了纯丙乳液的合成、性能，讨论了单体加入方式、反应温度、引发剂用量、乳化剂用量、纳米SiO2胶体添加量、pH值、聚合工艺等因素对乳液合成的影响，并对其进行了表征。     

中国化学化工文献聚合物乳液题录

~~（上接封3） 环氧-丙烯酸酯乳液的研制[刊]杨瑞芹，崔天放，陈尔凡，江伟（沈阳化工学院）//化学世界. 2002，43（1）.22～25，15 以甲基丙烯酸甲酯为硬单体，丙烯酸丁酯、丙烯酸-2-乙基己酯为软单体，丙烯酸、甲基丙烯酸β-羟乙酯功能单体，环氧树脂为改性剂，通过乳液共聚合制备环氧-丙烯酸酯乳液。讨论了乳化剂配比、用量、引发剂用量，反应温度，环氧树脂用量、环氧树脂的环氧值，双及软硬单体的配比对乳液聚合反应及涂膜性能的影响，确定了适宜的反应条件及较佳的配方。 丙烯酸酯-聚氨酯改性乳液的性能研究[刊]/李延科，凌爱莲，桑…     

抗冲ACR树脂的合成及其性能评价

采用种子乳液聚合法,以丙烯酸丁酯为核层单体、甲基丙烯酸甲酯为壳层单体、甲基丙烯酸烯丙酯为交联剂制备了抗冲ACR树脂。考察了不同加料方式对ACR乳液粒径及对PVC冲击性能的影响,结果表明:连续滴加方式可实现乳液粒径的稳定控制,并能得到性能优异的抗冲ACR树脂。     

环氧-丙烯酸酯乳液的研制

以甲基丙烯酸甲酯为硬单体 ,丙烯酸丁酯、丙烯酸 - 2 -乙基己酯为软单体 ,丙烯酸、甲基丙烯酸β-羟乙酯为功能单体 ,环氧树脂为改性剂 ,通过乳液共聚合制备环氧 -丙烯酸酯乳液。讨论了乳化剂配比、用量 ,引发剂用量 ,反应温度 ,环氧树脂用量、环氧树脂的环氧值 ,以及软硬单体的配比对乳液聚合反应及涂膜性能的影响 ,确定了适宜的反应条件及较佳的配方。     

常温固化水性环氧酯防腐涂料的研究

以环氧树脂和干性油脂肪酸为主要原料，合成了常温固化环氧酯树脂，并经乳化制得乳液。考察了环氧树脂、脂肪酸、酸值、乳化工艺等对乳液性能的影响。通过选用合适有效的闪蚀抑制剂和活性颜料，解决了以该乳液制得的水性涂料的闪蚀问题。本水性环氧酯防腐涂料性能与溶剂型环氧酯防腐涂料性能相当。     

含氟乳液的合成及其水性涂料性能第二部分——水性氟碳涂料的制备及其性能

将自制的甲基丙烯酸十二氟庚酯(FMA)-丙烯酸羟丙酯(HPA)-甲基丙烯酸月桂酯(LMA)-3-氯-2-羟基甲基丙烯酸丙酯(CHMA)四元共聚氟碳乳液(FHLC)与纳米TiO2等其他组分进行复配,制备了水性氟碳涂料,讨论了氟碳乳液和纳米TiO2的用量以及固化温度对涂层性能的影响,测定了氟碳涂层的水滴静态接触角.结果表明,当FHLC氟碳乳液用量为50g、纳米TiO2用量为20 g、固化温度为150℃时,所制备的水性氟碳涂料涂层的力学性能及耐水、耐酸、耐碱、耐沾污和耐洗刷等性能均符合国家有关标准要求,而且水接触角可达128°.     

交联改性苯丙乳液在水性油墨中的应用

分别以邻苯二甲酸二烯丙酯(DAP)、杂环甲基丙烯酸酯单体(TRM WAM Ⅲ)和乙酰乙酸基甲基丙烯酸乙酯(AAEMA)作为传统苯丙乳液的交联改性剂,采用预乳化半连续乳液聚合法制备交联改性苯丙乳液;然后以此为连接料,制备水性油墨.研究了传统苯丙乳液、交联改性苯丙乳液以及进口同类产品对水性油墨的摩擦牢度、稳定性能和耐水性能...     

废钢在底吹反应器中运动熔化及混匀的水模型实验

通过水模型实验,使用饱和氯化钾溶液制作的冰样模拟重型废钢,研究其在底吹气体搅拌反应器中的运动、融化及溶质的混匀规律。探究了单孔吹气模式下的液面高度、双孔吹气方式下的气体流量等因素对其的影响。结果表明,单孔吹气时,液面高度较低时(液面高度与直径比为0.42),气柱发展不充分,容器内环流较弱,盐球在气柱上下往复运动,融化较为缓慢。随着液面高度增加(液面高度与直径比为1.04),盐球随着环流运动,融化过程加快,按照98%标准得到的KCl的混匀时间甚至低于融化时间。双孔吹气时,A孔气体流量0.8 m3/h不变,B孔气体流量为0.5和1.0 m3/h时,盐球从吹气孔A上方加入后,在容器底部停留一段时间,在60~70 s之后才运动到顶部,沿着环流运动;B孔流量增加至1.5 m3/h时,盐球不会在底部停留,随气柱运动到吹气流量大的一侧的羽流区,其融化过程较快。在双孔吹气方案中,也发现了KCl的混匀时间低于融化时间的规律,这和融化末期盐球质量较小,释放的盐分较少有关。在本研究中,双孔吹气对盐球融化的促进作用不如单孔吹气且流量较大的方案。     

Mechanical properties of adhesive bonds reinforced with biological fabric

The paper deals with the utilization of a biological reinforcement in an area of an adhesive layer. An advantage of the biological reinforcement application is a simplification of following recyclation of adhesive bonds comparing to those with carbon and glass fibre based reinforcements. Biocomposites combining the biological reinforcement with an inorganic adhesive can be used in the area of connecting materials by means of the adhesive bonding technology. This study was focused on the analysis of an adhesive bond strength when the bonds were reinforced with biological fabric such as jute, flax and cotton. It evaluates the quality of the adhesive layer by means of SEM. The aim of this experiment was to describe an influence of the biological reinforcement in the form of fabric on the adhesive bond strength loaded with various loading speeds from 0.5 to 300 mm/min. The experimental part is devoted to the research on the influence of added fabrics of the natural origin on the shear strength of the adhesive bond which is prepared with the polymer adhesive. The experiment results proved a benefit of the reinforcing biological fabric in the layer of the adhesive. The reinforcement of the adhesive bond with the layer of the flax and the cotton showed in the positive way with the increase of the adhesive bond strength up of ca. 50%. The biological reinforcement was not fully wetted with the resin which did not considerably influence the adhesive bond strength.     

Pd-Pb/SiO2催化高浓度乙烯基乙炔加氢合成丁二烯

研究了硅胶负载钯铅双金属催化剂催化高浓度乙烯基乙炔加氢合成丁二烯过程。结果表明,加入适量的铅可起到分隔钯纳米粒子,阻碍钯纳米粒子团聚的作用,从而提高催化剂的催化活性,最佳Pb/Pd摩尔比为0.2。继续提高Pb/Pd摩尔比时,会生成铅钯合金相,造成催化剂活性降低。X射线光电子能谱结果表明,催化剂的催化活性与Pd 3d的电子结合能呈正相关关系。制备催化剂过程中,还原温度对催化剂的结构和催化性能影响显著。在350℃下还原得到的催化剂中金属氧化物还原不彻底,催化剂活性较低;还原温度为450℃时,则会引起钯纳米粒子烧结,造成催化剂的催化活性和对丁二烯的选择性同时降低;催化剂的最佳还原温度为400℃。在40℃催化乙烯基乙炔反应40 h后,积炭造成催化剂的孔道堵塞,催化剂失活。因此,需要进一步开展改善催化剂的抗积炭能力和使用寿命方面的研究。     

Combined electrochemical and surface analysis investigation of degradation processes in polymer electrolyte membrane fuel cells

Fuel cells allow an environmentally friendly and highly efficiently conversion of chemical energy to electricity and heat. Therefore, they have a high potential to become important components of an energy-efficient and sustainable economy. The main challenges in the development of fuel cells are cost reduction and long-term durability. Whereas the cost can be significantly reduced by innovative mass production, the knowledge to enhance the lifetime sufficiently is not available.Surface science analysis methods used for the characterization of the new and used electrodes can be use to determine the alterations in the fuel cell components and in this way to identify the degradation processes, but they do not allow to quantify the influence of the alterations in the electrodes on the electrochemical performance. For this purpose electrochemical methods are necessary; especially the electrochemical impedance spectroscopy (EIS) allows to separate the performance losses individually and to assign them to different components and processes of the cell via a model, whereas the choice of the right model can be problematic.Two important and distinct structural degradation processes were identified by surface analysis of the electrodes before and after fuel cell operation: first, the decomposition of poly tetra-fluoro-ethylene (PTFE) which is used as an organic binder and as a hydrophobic agent in the electrodes and second, a change of the structure of the catalysts. The observed decomposition of the PTFE is associated with a decrease of the hydrophobicity of the electrode. A loss of hydrophobicity influences drastically the required operation conditions and leads to a more critical water management of the fuel cell. In contrast, the alteration of the catalysts structure in the electrodes causes an irreversible decrease of the electrochemical performance. In polymer electrolyte fuel cells (PEFCs) a particle agglomeration of the platinum catalysts at the cathodes is detected.With EIS the effect of two different degradation processes in the membrane-electrode-assembly was quantified. During continuous operation the degradation of the PTFE induces an approximately two times higher performance loss compared with the performance loss related to the agglomeration of the platinum catalyst.     

ChMI/ MMA/AN悬浮共聚物与PVC共混的研究

通过悬浮共聚得到了N－环己基马来酰亚胺（ChMI）、甲基丙烯酸甲酯（MMA）、丙烯腈（AN）三元共聚物（PCMA），用作耐热改性剂与PVC共混。考察了共聚物用量对共混物热性能、力学性能、流变性能的影响，用扫描电镜（SEM）观察其断面。结果表明：随共聚物用量的增加，共混物的玻璃化温度和维卡软化点明显提高；PVC第一阶段降解速率减小，降解守毕后平台区残留量逐渐上升；拉伸强度明显提高，冲击强度在一定比例范围内几乎不变；熔体表观粘度增加，呈假塑性流体。     

扩压式自泵送流体动静压型机械密封性能分析

密封端面开启力是保证非接触式机械密封非接触运行的重要指标。为克服普通自泵送流体动静压型机械密封端面开启力随转速增大而减小这一不足，基于离心式泵或压缩机的扩压器工作原理提出了一种扩压式自泵送流体动静压型机械密封。数值模拟比较了普通自泵送和扩压式自泵送流体动静压型机械密封的密封性能，探讨了密封面结构参数和工况参数对扩压式自泵送流体动静压型机械密封性能的影响规律。结果表明：扩压式自泵送流体动静压型机械密封相比同等螺旋槽参数的普通自泵送流体动静压型机械密封的密封界面开启力提升了50%以上，并随转速增大而增大；随着扩压环槽增宽，开启力和泄漏率都显著增大；减小扩压环槽深度，能有效提高开启力；扩压环槽结构尺寸的变化基本不影响槽扩宽比、槽数和螺旋角对密封性能的影响规律。在一定的工况参数下，通过结构参数匹配，扩压式自泵送流体动静压型机械密封可以获得较优的密封性能。     

Écoulement de Taylor‐Couette en géométrie finie et à surface libre

The reactors of Taylor‐Couette type are relatively recent application in the engineering processes field. The stability and the flow structure in this device are examined under the effect combined of the free surface and the fluid's height in annular space. The exploitation of the flow regimes is carried out according to the number of Taylor for various values of aspect ration Γ. By means of ultrasonic velocimetry (UPV) we determine axial average velocity profile and the axial wavelength. We also carry out the spectral analysis by Fourier's fast transform of the fluctuations associated with the average velocity values in order to analyze the flow structure. We particularly aim for checking the presence or the absence of the azimuth wave according to the filling height and the rotational velocity imposed. We highlight the effects of free surface and aspect ratio on the conditions of appearance of the second instability ( wavy mode). The analysis of the fluctuation shows that the appearance of the azimuth wave regime (Wavy mode) is delayed when the aspect ration decreases. Below a critical value noted Γc = 10, the azimuth wave regime is not observed any more.     

台阶式并行微通道内液液两相流流型及其转变机理

利用高速摄像仪研究了台阶式并行微通道内液液两相流流型及其转变机理。以甘油水为分散相、含3% Span 85的环己烷为连续相,观测到了滴状-滴状流、过渡-滴状流、喷射-过渡流和喷射-喷射流4种流型;以两相流量为坐标轴绘制了流型图,并获得了流型转变线;分析了流型的转变机理。考察了分散相黏度对流型及其转变的影响机制。随着分散相黏度的增大,流型转变线整体向下移动,滴状-滴状流区域变小,喷射-喷射流区域变大。最后,运用介尺度概念分析了并行微通道内液液两相流非均匀结构的动态效应。     

Confocal microscope—A valuable tool for examining wood-coating interface

The suitability of confocal laser scanning microscopy (CLSM) in examining a wood-coating interface was evaluated using a clear coating system. A comparison of the images of the wood-clear coating interface obtained using CLSM and light microscopy (LM) showed a marked superiority of CLSM in revealing the details of the physical nature of the interaction between the clear coating and the wood cell walls in the surface layer. The most distinct advantage of CLSM was in its ability to clearly resolve penetration of the coating into very fine cracks in cell walls, details not obtainable with LM. The information presented here demonstrates that CLSM has the potential to greatly enhance our understanding of the physical aspects of an interaction between the wood and coating at the interface.     

Influence of organic pigment particles on millbase flow of nitro-cellulose/alcohol-rich liquid inks

Millbase flow of nitro-cellulose/alcohol-based inks deteriorates above a critical pigment weight fraction in the ink which differs from pigment to pigment. Below this critical concentration the inks are flocculation-resistant by virtue of a stabilizing adsorbed layer of NC resin on the pigment particle surfaces. The pigment particles are large aggregates of crystals, from which additives such as abietyl resin have been shown to dissolve off into the ink medium. The aggregates are associated with liquid medium immobilized within the shear boundary near the pigment/medium interface (includes adsorbed layers and liquid within pores). This results in the effective pigment volume fraction in the ink being higher than that calculated from the weight fraction. When considered in terms of the effective volume fraction, most of the pigments have the same critical concentration of about 0.2–0.25. This indicates that deterioration in flow at higher concentrations is due in the first instance to crowding of particles, rather than to the failure of the mechanism of flocculation resistance per se. The robustness of the flocculation resistance is indicated by a low rate of increase of the strength of the structure with an increase in the effective volume fraction above the critical concentration. Robustness is important in maintaining manageable flow at high concentrations. Increasing the proportion of ethyl acetate in the solvent blend can adversely affect the millbase rheology of dispersions of some pigments in NC ink media due to induced flocculation and structure formation. The improved solvency of the blend for NC resin has been shown to reduce the amount of NC resin adsorbed on the particles of an ester-sensitive pigment. Other pigments give inks with rheology insensitive to ester content. This is attributed to more specific interaction of the NC resin with the pigment particle surfaces. The effect of temperature on flocculation resistance is consistent with these views.