Effects of mixing conditions on the reaction of 3‐octanoylthio‐1‐propyltriethoxysilane during mixing with silica filler and natural rubber

The effects of mixing temperature and mixing time on the reaction of 3‐octanoylthio‐1‐propyltriethoxysilane (NXT silane) during mixing with precipitated silica and natural rubber (NR) were investigated. Results showed that the reaction between NXT silane and precipitated silica can proceed at temperatures above 130°C. Because of the blocking group of NXT silane, the silane–NR coupling reactivity is low, so that the reaction of NXT silane with NR occurs only during the curing period. There is no reaction between NXT silane and NR during mixing, which showed that the mixing time of silica‐filled NR compound containing NXT silane must be longer than 10 min at 150°C to obtain the desired silane coupling efficiency. With increasing mill temperature, the coupling efficiency increases. A high mixing temperature promotes improvement of silane–silica coupling efficiency, although the tensile strength, 100% modulus, 300% modulus, and hardness of NR vulcanizates decrease. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 2295–2301, 2004     

基于RFID技术的室内机器人定位方法的研究

近年来,随着RFID技术的日益成熟,它在机器人领域的应用变得越来越广泛而深入。文章首先分析了RFID技术在室内环境下应用于移动机器人自我定位的可行性,然后描述了使用蒙特卡罗概率统计模型对机器人附近的RFID标签进行方位定位的过程,并且阐述了利用在此过程中获得的数据对自身或者特定物在特定环境下进行方位定位的方法,最后文章分析了此技术在某些特定场合进行应用推广的可行性和前景。     

乐高NXT机器人系统C＋＋程序设计

随着乐高NXT机器人系统在国内中、小学的深入推广,有必要对乐高NXT机器人系统的相关问题尤其是二次开发问题做进一步深入探讨、研究。利用乐高LEGO MINDSTORMS NXT机器人系统的SDK文件FantomSDK,借助C＋＋编程,结合LEGO MINDSTORMS NXT Bluetooth Developer Kit文件,代替NXT-G、RoboLab软件,实现对乐高NXT设备的完全控制,为青少年、科技教师运用乐高NXT机器人系统进行科技创新提供帮助与支持。     

硅烷偶联剂对白炭黑胶料性能的影响

研究硅烷偶联剂Si75和NXT对白炭黑胶料性能的影响。结果表明,与偶联剂Si75胶料相比,偶联剂NXT胶料的门尼粘度较低,硫化时间较长,定伸应力和拉伸强度较小,拉断伸长率较大,动态性能差别不大。     

Effects of silane coupling agents on the vulcanization characteristics of natural rubber

The vulcanization characteristics of silica‐filled natural rubber (NR) were studied in the presence of silane coupling agents, 3‐octanoylthio‐1‐propyltriethoxysilane (NXT) and bis [(3‐triethoxysilylpropyl) tetra sulfide] (TESPT, or Si‐69). The scorch time, cure rate index, and the rate constant of NR were measured using an Oscillating Disk Rheometer in the temperature range of 140–170°C. The scorch time of NR decreases with increasing TESPT and NXT concentrations, and the scorch time of NR compound with NXT is longer than that with TESPT. The apparent activation energies of vulcanization for the compounds with NXT and TESPT both decrease with increasing silane concentration. The apparent activation energy of vulcanization of NR compound with NXT is lower than that with TESPT at various concentrations. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1511–1518, 2004