新型紫外光固化粘接性单体的合成与应用研究

以甲基丙烯酸、1,10-癸二醇和三氯硫磷为主要原料合成出了紫外光固化粘接性单体10-甲基丙烯酰氧癸基硫磷酸二氯.用¹H-NMR、³¹P-NMR和FT-IR对产物结构进行了表征确认.通过剪切强度的测试评价了其对复合树脂与钛合金、钴铬合金之间的粘接所起到的作用.结果表明,10-甲基丙烯酰氧癸基硫磷酸二氯与水和三乙胺的混合溶液能够促进复合树脂与钛合金、钴铬合金的粘接,剪切强度分别达到17.3 MPa、18.1 MPa.     

材料力学性能退化的超声无损检测与评价

材料性能退化总是伴随着某种形式的材料非线性力学行为, 从而引起超声波传播的非线性, 即高频谐波的产生.基于此,材料和结构的超声无损检测与主人技术发展成起来.首先介绍固体介质内的非线性超声波动方程的基础, 并综述了利用超声波传播的非线性特性对结构材料和粘结面的力学性能退化进行无损检测与评价的研究进展.之后对材料在疲劳、拉伸以及蠕变载荷作用下, 其力学性能退化进行超声无损检测与评价的试验研究进行了介绍;综述了超声波传播非线性的机理研究, 以及利用超声波对粘结面的粘结强度及其力学性能退化评估所开展的研究. 最后指出了今后该领域需要进一步研究的问题.      

评估TiN薄膜与基材结合的划痕试验及有限元模拟

通过有限元模型模拟划痕试验得到的结果表明∶切应力的起伏变化?膜/基界面处切应力差值?接触区附近膜层表面张应力?高载下的几种应力集中等,对膜/基体系的失效都有重要的作用.通过模型计算临界载荷下的膜/基界面处切应力差值,可用来评价膜层与基材的结合强度;提出了划痕试验中膜/基体系失效的2种机制.不同性能基材的TiN膜/基体系划痕试验结果,可验证本文有限元模拟的有效性,并表明临界载荷是膜/基结合强度?体系承载能力?内聚结合性能等的综合反映;低载往复摩擦磨损试验的结果进一步证实,用划痕试验的临界载荷评估膜/基结合强度具有局限性.     

Effect of the Amount of Calcium Carbonate as Filler on the Rheological and Adhesion Properties of a Water-Based Polyurethane Dispersion

In this study, the properties of water-based adhesives based on a polyurethane ionomer (PUD) and a micronised CaCO₃ as filler was analysed. Different amounts of a micronised CaCO₃ (5-25 wt%) were added to water-based polyurethane (PUD) adhesive formulations in order to reduce its relatively high cost. The addition of a micronised calcium carbonate filler increased the viscosity, the storage and loss moduli of the PUD adhesives, and imparted pseudoplasticity and thixotropy, more noticeably for the adhesive with the highest calcium carbonate content. The creation of acid-base interactions seemed to be responsible for the improvement in the rheological properties of the PUD adhesives containing CaCO₃ as filler. On the other hand, the addition of CaCO₃ filler might deteriorate the adhesion properties to PUD adhesives.     

丙烯酸酯-乙酸乙烯酯共聚物压敏粘合剂的合成及性能

丙烯酸酯-乙酸乙烯酯共聚物压敏粘合剂的合成及性能     

Analysis of contact stresses in structural joints of composite shell with steel banding

Based on the generalized Timoshenko-type shell theory, a numerical-analytical procedure for determining contact stresses from the interaction between a cylindrical composite shell and rigid bandings is proposed. Specific cases of loading and contact interaction (ideal contact through an adhesive interlayer) are considered. The contact problems are reduced to the solution of a Fredholm integral equation of the second-kind. A calculation analysis is performed. Translated from Mekhanika Kompozitnykh Materialov, Vol. 35, No. 1, pp. 109–120, January–February, 2000.     

Characterizing Key Volatile Pollutants Emitted from Adhesives by Chemical Compositions,Odor Contributions and Health Risks

As one of the major sources of volatile pollutants in indoor air, gaseous emissions from adhesives during interior decoration have attracted increasing concern. Identifying major volatile pollutants and the risk in adhesive gaseous emissions is of great significance, but remains rarely reported. In the present research, we assessed the major volatile pollutants emitted from white emulsion adhesive and silicone adhesive samples (n = 30) from three aspects: chemical composition, odor and health risk contributions. The results showed that a total of 21 volatile pollutants were detected. Significantly, xylene was the most concentrated compound from white emulsion adhesives, accounting for 45.51% of the total concentrations. Butanone oxime was the most concentrated compound in silicone adhesives, accounting for 69.86% of the total concentrations. The trends in odor concentration (evaluated by the odor activity value method) over time were well correlated with the total chemical concentrations. Xylene (58.00%) and butanone oxime (76.75%) showed the highest odor contribution, respectively. Moreover, from an integrated perspective of chemical emissions, odor and health risk contributions, xylene, ethylbenzene, ethyl acetate and benzene were identified as the key volatile pollutants emitted from the white emulsion adhesives, while butanone oxime, butanone, and ethanol were the key volatile pollutants emitted from the silicone adhesives. This study not only identified the key volatile pollutants but also provided characteristics of odor and health risks of gas emitted from adhesives.     

气流纺杯轴承磨损失效的分析与机理探讨

本文从宏观、微观及轴承润滑等角度出发,对具有高速、轻载和高精度特征的气流纺杯滚动轴承的磨损失效进行了分析与机理探讨,认为这种轴承磨损失效是粘着磨损和磨粒磨损的结果,而不是接触疲劳破坏所致。作者指出,在稳定磨损阶段也还存在着一些导致过渡急剧磨损阶段形成的不利因素,其在运转过程中被迫紧急刹车时,由于轴承受力突然增大和润滑脂膜破裂,造成摩擦界面温度急剧升高而使滚动元件的表层组织软化,润滑脂也随之逐渐丧失润滑能力,摩擦界面亦变得粗糙不平,比膜厚下降而发生了微凸体间的频繁接触,由此引起的粘着现象是造成气流纺杯滚动轴承磨损失效最主要的原因;由于轴承壳腔内的旧润滑脂无法取出,脂中所含的金属磨屑硬粒子在不断增多,其在高速滚动体发生滑动摩擦的瞬间会对材料表面造成擦伤或犁沟,这是导致滚动轴承磨损失效不可忽视的另一因素。     

导电颗粒属性对各向异性导电粘合剂电导的影响

利用差分法对导电粘合剂中导电颗粒的属性(包括导电颗粒的形状、大小等)对导电粘合剂电导的影响进行了计算.在交流信号下，导电粘合剂的金属填充颗粒越小，导电粘合剂的电导越大.通过理论计算发现，导电粘合剂的导电颗粒若为球形(正方体)，导电粘合剂的电导与金属颗粒的半径(边长)成反比例变化；若为长方体或圆柱体颗粒，则电导随颗粒高度的增加而减小，而基本不随颗粒底面积的改变而变化. 关键词： 导电粘合剂 电导 导电颗粒 差分法     

羟基封端聚丁二烯的临界点色谱定量方法研究

为建立混合物中羟基封端聚丁二烯（HTPB）的临界点色谱定量方法，以C18为固定相，考察了HTPB在四氢呋喃-乙腈和四氢呋喃-水两种流动相体系下的临界点色谱条件。结果表明，四氢呋喃-乙腈体积比为70.7：29.3以及四氢呋喃-水体积比为92：8时，HTPB的保留值与其相对分子质量无关。将该临界点色谱方法用于胶黏剂混合组分中HTPB的测定，结果表明，HTPB在46.7~216.4 mg/L范围内呈良好线性关系，相关系数（r）>0.99，检出限为4.2 mg/L。自配HTPB和矿物油双组分样品的加标回收率为89.2%~101.1%，相对标准偏差小于0.66%（n=6）。应用该方法对市售聚氨酯胶黏剂进行检测，测定结果为HTPB成分占26.6%。该方法快速、准确，能满足聚合物混合产品的生产质量控制和失效分析的要求。