Preparation of self-crosslinked acrylate emulsion with high elasticity and its rheological properties

Using butyl acrylate（BA）,methyl methacrylate（MMA）,methacrylic acid（MAA） and mixed emulsifier as raw materials,the self-crosslinked emulsion was prepared via pre-emulsified and semi-continuous seeded emulsion polymerization technology in the presence of N-hydroxymethyl acrylamide and poly solidum maleate. The influence of mass ratio of BA to MMA,amount of N-hydroxymethyl acrylamide and poly solidum maleate on the rheological properties of the self-crosslinked emulsion was studied. Possible cross-linked mechanism of self-crosslinked monomer was investigated. And the relationship between emulsion viscosity and shear rate was investigated. The results show that the self-crosslinked acrylate emulsion with high elasticity can be synthesized when the mass fractions of BA is 60%,MMA is 40%,and added amount of N-hydroxymethyl acrylamide is 2.5%-3.0% and added amount of poly solidum maleate is 0.3%-0.4%. The self-crosslinkage process of N-hydroxymethyl acrylamide involves two steps. One is copolymerization of N-hydroxymethyl acrylamide and acrylate,the other is cross-linkage among polymer molecules via condensation reaction of methylol. The emulsion is of rheological properties of pseudo-plastic fluid and belongs to non-Newtonian fluid.     

紫外光固化纳米抗菌木器漆

在紫外光固化涂料体系中加入无机纳米抗菌剂,考察了体系黏度和二氧化硅对无机纳米抗菌剂分散稳定性的影响,制备了紫外光固化纳米抗菌木器漆,测试了其光泽、硬度、耐水性、耐醇性和耐磨性等理化性能以及抗菌性能,结果表明:该涂料具有良好的理化性能,对大肠埃希氏菌和金黄色葡萄球菌的抗菌率达到99%以上。     

掺银纳米TiO2P内墙涂料的制备及性能研究

以自制的掺银纳米TiO2为功能性组分,制备纳米TiO2光催化改性涂料,并对其抗菌性、去除有机物性能及理化性能等进行了研究。实验表明,该涂料在可见光下具有优异的抗菌性、降解苯及甲醛的功能。     

耐寒增塑剂的应用及发展

详细介绍了耐寒增塑剂的品种及相关应用。综述了耐寒增塑剂在近年来所取得的技术进步,展望其未来耐寒增塑剂的发展趋势。     

鋁和鋁上各种电鍍层面接触电阻值的测定

一、测定目的 高压开关导电系統各接触部分的温升值,是一个重要的技术数据。而温升值又和接触电阻的大小有直接关系。故在一定的接触压力下,测定用不同的材料和以不同的接触形式接触时的接触电阻值,是一項重要的工作。目前,有关鋁在这方面的資料較缺,因此,我們进行測定未絰和經过各种不同表面处理之铝板的接触电阻值。由于人力及时間的限制,这次只測定了在一定接触压力下未經和經过各种表面处理的鋁板之面接触电阻值。     

鋁和鋁上各种鍍复层与銅板联接时在濃縮工业性大气中的腐蝕試驗

一、試驗設备、条件及經过 1.以容积为20公升带有平权玻璃盖的长方形玻璃缸作容器,容器中放一木或玻璃質的框架以悬挂試驗样板。 2.密閉器中含有2％的SO_2气体,并加入了66克的固体二氧化碳(干冰)。此外尚加入了500克蒸溜水,以保証容器内保持有将近飽和的湿度。 3.所有样板均用馬尾悬于框架上,样板之間保持30——40毫米的距离,样板底边与容器底部液面的距离不小于60毫米。 4.平板玻璃盖与玻璃缸的密封是在接合面上涂抹凡士林,然后,在玻璃盖上放一重物以防止蠕动。     

湍流-层流气液分层流的模型

The time-dependent liquid film thickness and pressure drop are measured by using parallel-wire conductance probes and capacitance differential-pressure transducer. A mathematical model with iterative procedure to calculate holdup and pressure drop in horizontal and inclined gas-liquid stratified flow is developed. The predictions agree well with over a hundred experimental data in 0.024 and 0.04 m diameter pipelines.     

三维湍流回流气相和煤粉燃烧辐射传热离散坐标模型和热流模型比较

针对空腔内纯三维辐射传热和大速差射流燃烧室内三维湍流回流气体燃烧和煤粉燃烧,对其中辐射传热分别采用离散坐标模型和热流模型进行了分析与比较。模拟结果表明,两种模型所得到的温度分布在趋势上类似,而在定量上有差别。对纯辐射传热模拟,与区域法的精确数据对比表明,离散坐标模型的结果更合理。对燃烧的模拟结果是,离散坐标模型所得的气体温度要高于热流模型的相应值,亦即热流法低估了气体温度和壁面热流。二者所得到的速     

碳纤维/环氧树脂复合材料的改性及改性机理

介绍了碳纤维/环氧树脂复合材料中碳纤维的增强机理.综述了纳米材料、聚合物对碳纤维/环氧树脂复合材料的改性进展,并总结了相应的改性机理.探索新型柔和的碳纤维表面处理技术以及对碳纤维表面接枝将是碳纤维/环氧树脂复合材料改性的发展方向.