含氟丙烯酸硅酯自抛光防污涂料的研制

制备了既具有低表面能性能又具有自抛光性能的含氟丙烯酸硅酯树脂,讨论了含氟丙烯酸单体用量对树脂水解性能的影响,并对树脂结构进行了表征;采用制备的含氟丙烯酸硅酯树脂制备了无锡环保型自抛光防污涂料,并对其性能进行了研究,结果表明该自抛光防污涂料具有良好的防污性能。     

有机氟阴极电泳涂料的制备工艺

水性含氟涂料既具有氟树脂的耐候、耐污、耐腐蚀等性能,又具有水性涂料环保、安全等性能,目前国内对此研究还不够深入。以环氧树脂为主体,选择合适的丙烯酸单体、有机氟单体对其改性,合成了同时具备环氧树脂、丙烯酸树脂、氟树脂性质的阳离子型含氟环氧丙烯酸树脂,并以此为主体树脂制备出水稀释型阴极电泳涂料,重点探讨了含氟单体的种类和数量、反应温度、反应时间等因素对树脂合成以及漆膜性能的影响。结果表明:在合适的工艺条件下,可以得到高耐腐蚀性、耐老化性、自洁性的电泳漆膜。     

基于低表面能树脂的海洋防污涂料的研究进展

从基团转移聚合、阳离子聚合、阴离子聚合、活性官能团之间的反应和自由基聚合5个方面简单综述了低表面能树脂的聚合机理;详细介绍了以有机硅树脂、氟碳树脂、氟硅树脂以及不含氟硅元素树脂为基体的防污涂料;分析讨论了低表面能海洋防污涂料的控制因素;并展望了低表面能防污技术的发展方向。     

含氟丙烯酸酯单体的合成及固化膜的性能

以六氟环氧丙烷低聚物和(甲基)丙烯酸-β-羟乙酯为起始原料,合成了(甲基)丙烯酸-β-(全氟烷氧基酰基)乙酯四种新型含氟单体,其结构经红外光谱(FT-IR)、核磁共振(1H-NMR和19F-NMR)确证。初步考察了上述单体对丙烯酸酯类紫外光固化涂料的改性作用,结果表明,提高含氟组分比例对固化膜的初始水接触角影响较小,但经过加热后处理可显著增强固化膜的疏水性。由此推断,热处理能有效促进含氟侧基向表面迁移,且含氟侧链越长,这种向空气界面富集的倾向尤为明显。当含氟组分占涂料配方的4%～6%(质量分数,下同)时,固化膜的最大水接触角可达到120°。     

氟/硅丙烯酸树脂防污涂层的制备及性能研究

以全氟烷基乙基甲基丙烯酸酯为功能单体,采用自由基聚合法制备了具有防污性能的低表面能氟/硅丙烯酸树脂涂层,重点探讨了有机氟含量对树脂涂层的接触角、玻璃化转变温度、附着力、硬度等性能及单体转化率的影响,确定了氟/硅丙烯酸涂层的最佳制备条件。结果表明,氟/硅单体成功与丙烯酸单体发生共聚,当氟/硅丙烯酸涂层中的氟质量分数为14.60%时,树脂涂膜的接触角为103.7°,与基体结合力优异,同时具有良好的防腐性能。     

高性价比氟涂料的研究

为了开发一种性价比高的含氟涂料,通过分子设计合成了一种常温固化低氟树脂,用XPS(X射线光电子仪)检测了树脂成膜后含氟成分的分布情况,测量了涂膜与纯水的接触角,把树脂分离提纯除去含氟均聚物和未反应氟单体后,测量了聚合物的红外光谱图,因而推断了合成树脂的分子结构.应用合成树脂制作了一种含氟涂料,并检测了色漆涂膜耐蚀、耐候、耐盐雾等性能.试验结果表明:通过分子设计合成的氟树脂成膜时产生了较大趋向作用,含氟基团向空气/聚合物界面伸展,对聚合物内部分子形成很好的保护作用;低氟树脂涂料具有优异的耐候性能和耐蚀性能;研制的涂料具有性价比高的特点.     

含氟丙烯酸树脂的合成及性能研究

以甲基丙烯酸甲酯(MMA)、丙烯酸丁酯(BA)为主要单体,甲基丙烯酸全氟烷基酯(FMA)为合氟单体,甲基丙烯酸羟基乙酯(HEMA)为交联单体,采用溶液聚合法合成含氟丙烯酸树脂,并与固化剂六甲撑二异氰酸酯(HDI)三聚体固化成膜.研究了软硬单体配比、羟值、聚合温度、氟单体含量及添加方式等因素对树脂粘度、分子量及其分布以及涂膜的疏水性、硬度、附着力和耐热性的影响.结果表明,在m(BA):m(MMA)=6:4、羟值为64.8mg/g、氟单体用量为3%且采用后期添加、反应温度为85℃的条件下制得了含氟丙烯酸树脂,其分子量Mn=26980,分布窄(D=1.391),涂膜与水的静态接触角达到110°,硬度为1H,附着力为0级,分解温度为310℃.     

核-壳含氟硅织物整理剂的可控制备及其表征

采用电子转移活化再生催化剂原子转移自由基聚合(ARGET ATRP)引发含氟丙烯酸酯单体在纳米SiO2表面上的聚合反应,合成核-壳型含氟硅聚合物乳液,并用于棉织物的拒水拒油整理。聚合反应动力学表明酯单体在SiO2表面的聚合是一个活性可控的过程,所得聚合物分子量大小可控、分子量分布较窄。利用FT-IR、1 H NMR、19F NMR、XPS以及TEM等对聚合物乳液的结构和形态进行表征分析,证明其核-壳结构及氟的存在。所合成的纳米级聚合物乳液通过与织物表面形成微纳二元阶层结构,提高其拒水拒油性。     

氟硅氧烷共聚低表面能杂化材料的研究

通过溶液聚合和溶胶-凝胶法复合工艺,采用甲基丙烯酸十二氟庚酯(FA)为含氟单体、乙烯基三乙氧基硅烷(VTES)为硅单体和正硅酸乙酯(TEOS)为无机相前驱体直接合成了一种分子级复合,最外层含氟侧链定向于空气,中间层是碳碳主链,底层为硅氧网络结构的氟硅氧烷共聚低表面能杂化材料.结果表明,溶剂含量对含氟侧链向表面的迁移速度以及材料疏水性能有着非常重要的影响.     

NAD型易涂施含氟涂料

日本关西涂料公司的含氟树脂NAD化(聚合物非水性分散化)技术属世界首创。这一技术是在聚四氟乙烯-乙烯基醚共聚物溶液中添加丙烯酸单体,在分散聚合过程中,丙烯酸聚合物粒子在有机溶剂中析出。在丙烯酸单体聚合的同时,氟树脂的官能基与丙烯酸树脂的官能团反应,生成的丙烯酸聚合物粒子都被氟树脂层均匀包覆,形成粒径为     

Estimation of Parameters of Universal Distribution of Moments of Failure of Products

A method is proposed for estimating the parameters of a mixture of exponential and Weibull distributions for which the accuracy of preliminary estimates obtained by graphical analysis is refined in accordance with the criterion of maximum likelihood. The efficiency of the proposed method is supported by the results of statistical modeling.     

Evaluation of optical properties of highly scattering media by moments of distributions of times of flight of photons

A novel method for the determination of the optical properties of tissue from time-domain measurements is presented. The data analysis is based on the evaluation of the first moment and the second centralized moment, i.e., the mean time of flight and the variance of the measured distribution of times of flight (DTOF) of photons injected by short (picosecond) laser pulses. Analytical expressions are derived for calculation of absorption and of reduced scattering coefficients from these moments by application of diffusion theory for infinite and semi-infinite homogeneous media. The proposed method was tested on experimental data obtained with phantoms, and results for absorption and reduced scattering coefficients obtained by the proposed method are compared with those obtained by fitting of the same data with analytical solutions of the diffusion equation. Furthermore, the accuracy of the moment analysis was investigated for a range of integration limits of the DTOF. The moment analysis may serve as a comparatively fast method for evaluating optical properties with sufficient accuracy and can be used, e.g., for on-line monitoring of optical properties of biological tissue.     

Estimation of potentialities of methods of summation of direct measurement errors

Conventional methods for summation of direct measurement errors are considered. Conditions under which these methods provide consistent results are stated. It is proposed to utilize for characteristic of the total error, its interval estimator or the half-sum of the value obtained by adding up its arithmetic and geometric random errors.Translated from Izmeritel'naya Tekhnika, No. 4, pp. 10–12, April, 1995.     

空压机轴承箱蜗壳温度探头油封改造

由于空压机进气侧轴承箱蜗壳温度探头密封效果不好,使空压机及其后续管道受到油污染。后将温度探头的O形圈密封改为骨架油封,杜绝了轴承箱漏油问题。文章简介空压机的结构和技术参数,详细介绍了骨架油封的制作和优点。     

Characteristics of mechanical properties of materials in studies of conditions of attainment of marginal states

It is shown that conditions of attainment of marginal states in the material of structural components are formulated on the basis of analysis of force and deformation criteria of formation and development of destruction. The parameters of these criteria are data on types of structural materials, standard and special characteristics of their mechanical properties, structural forms of considered elements of the equipment, and their operating stress loading. In this case, the construction of a system of state equations for describing interrelation of current damage, external actions, and responses to them is based on the concept of calculating variations in properties of materials at all stages of the design life cycle.     

Determination of parameters of microstructural inhomogeneity of deformation of metals by the method of modeling

The article suggests a method of evaluating the microstructural inhomogeneity of deformation of metals by modeling. The method includes the measurement of deformations of metal according to meshes of a dividing grid with small base and the calculation of the distribution parameters of microdeformations in model representation. It is shown that the modeling method makes it possible objectively to evaluate the microinhomogeneity of deformation of metals independently of the chosen mesh size of the dividing grid. New structural characteristics are introduced: the base and wave of variation expressing the degree of crumbling or amalgamation of metal grains by inhomogeneity of deformation.Translated from Problemy Prochnosti, No. 7, pp. 40–44, July, 1991.     

Analysis of the rate of propagation of the wave of change of boiling modes

An approximate analytical expression is derived for the velocity of the front of the wave of change of boiling modes on a rod and on a plate. The impact of the Thomson effect and of the heater orientation in the gravity field is included. Adequate agreement is demonstrated between the derived relations and experimental data.     

水三相点复现的不确定度评定

水三相点是开尔文热力学温度的唯一基准点，也是ITS-90国际温标重要的定义固定点。因此，水三相点不确定度分析对整个温标的建立、温度量值传递起着至关重要的作用。近3年来，中国计量科学研究院研制出一系列高质量的水三相点容器，加强了水三相点的研究，为不确定度的分析提供了更为可靠的实验依据。同时，不确定度的分析也是客观评价新研制容器性能的一个重要指标。因此，根据实验结果对新研制容器所复现的水三相点进行了不确定度评定。评定结果表明，其扩展不确定度为0．16mK(k=2．69，P=0．99)。