双功能交联剂WY988在轮胎胎肩垫胶中的应用

研究双功能交联剂WY988在轮胎胎肩垫胶中的应用.结果表明:在胎肩垫胶中加入双功能交联剂WY988,胶料的t10和t90缩短,抗硫化返原性能提高,损耗因子(tanδ)减小;随着双功能交联剂WY988用量的增大,硫化胶的物理性能下降,tanδ增大;双功能交联剂WY988用量为0.5份,同时减小硫黄或促进剂的用量,硫化胶的物理性能较好,tanδ减小,成品轮胎的耐久性能提高.     

NR硫化返原过程的动力学研究

采用依据ＮＲ硫黄硫化返原机理建立起来的硫化返原动力学模型,对普通硫黄硫化体系和半有效硫化体系的ＮＲ在不同温度下的硫化曲线进行了计算机非线性拟合,从而求出了各步反庆的速率常数,并进上步得到多硫键、双硫键和单硫键密度之和及交联密度随硫化时间变化的关系。结果表明：不同温度下两种体系采用该模型得到的模拟曲线与实际数据相吻合,求出的同一体系速率常数与硫化温度的关系符合Ａｒｒｈｅｎｉｕｓ方程。两种体系多硫键的     

双-1,6-(二乙基硫代氨甲酰-二硫化)己烷的制备与应用

用1,6－二氯己烷与硫代硫酸钠合成了六亚甲基－1,6－二硫代硫酸二钠盐,进而制备了新型硫化剂双－1,6－（二乙基硫代氨甲酰－二硫化）己烷。有红外光谱和质谱仪对中间体及产物进行了表征,探讨了产物对天然橡胶的抗硫化返原作用机理,并开展了应用研究,结果表明,用双－1,6－（二乙基硫代氨甲酰－二硫化）己烷组成的硫化体系硫化的橡胶具有优异的抗硫化返原性和动态疲劳性能。     

Effect of triacylglycerol composition and structures on oxidative stability of oils from selected soybean germplasm

The oxidative stability of soybean oil triacylglycerols was studied with respect to composition and structure. Crude soybean oils of various fatty acid and triacylglycerol composition, hexane-extracted from ground beans, were chromatographed to remove non-triacylglycerol components. Purified triacylglycerols were oxidized at 60°C, in air, in the dark. The oxidative stability or resistance of the substrate to reaction with oxygen was measured by determination of peroxide value and headspace analysis of volatiles of the oxidized triacylglycerols (at less than 1% oxidation). The correlation coefficients (r) for rates of peroxide formation (r=0.85) and total headspace volatiles (r=0.87) were related positively to oxidizability. Rate of peroxide formation showed a positive correlation with average number of double bonds (r=0.81), linoleic acid (r=0.63), linolenic acid (r=0.85). Rate of peroxide formation also showed a positive correlation with linoleic acid (r=0.72) at the 2-position of the glycerol moiety. A negative correlation was observed between rate of peroxide formation and oleic acid (r=−0.82). Resistance of soybean triacylglycerols to reaction with oxygen was decreased by linolenic (r=0.87) and increased by oleic acid (r=−0.76)-containing triacylglycerols. Volatile formation was increased by increased concentration of linolenic acid at exterior glycerol carbons 1,3 and by linoleic acid at the interior carbon 2. Headspace analysis of voltiles and high-performance liquid chromatography of hydroperoxides indicated that as oxidation proceeded there was a slight decrease in the linolenic acid-derived hydroperoxides and an increase in the linoleic acid-derived hydroperoxides. The oxidative stability of soybean oil triacylclycerols with respect to composition and structure is of interest to the development of soybean varieties with oils of improved odor and flavor stability. Presented at the 81st Annual American Oil Chemists' Society Meeting, Baltimore, MD, April 18–21, 1990.     

NR硫化返原动力学及主要抗硫化返原助剂

对硫化返原的动力学、抗硫化返原助剂的作用机理、不同抗硫化返原助剂在不同的配合体系中的用量及对硫化胶性能的影响进行评述。对于抗硫化返原助剂,在半有效硫化体系中Ｓｉ６９抗返原性最好。在传统硫化体系中ＨＶＡ－２最好。实际应用时不同本的配方应采取相应的抗硫化还原剂。     

双马来酰亚胺衍生物对炭黑填充NR/ SBR并用胶硫化特性的影响

测定了含双马来酰亚胺衍生物（Ｐｅｒｋａｌｉｎｋ９００）的充炭黑ＮＲ／ＳＢＲ并用胶质量比为８０／２０时,于１４５℃×６０ｍｉｎ,１８０℃×３０ｍｉｎ的硫化曲线,考察了Ｐｅｒｋａｌｉｎｋ９００用量对混炼胶硫化特性的影响。结果表明,在试验范围内,Ｐｅｒｋａｌｉｎｋ９００的加入不改变胶料的焦烧和正硫化,但能有效地改善胶料的流动特性;可提高橡胶的抗撕裂性能,且不影响其他物理机械性能;对胶料的硫化返原性具有显著的改进效果。Ｐｅｒｋａｌｉｎｋ９００加入量以１．０份为宜。     

抗硫化返原助剂的应用与进展

简要介绍国内外各类抗硫化返原助剂的特性和用法，品种包括1，3-双(柠康酰亚胺甲基)苯、六甲撑-1，6-双硫代硫酸钠二水合物、有机锌皂类耐热硫化活性剂及抗返原性优异的新型硫化剂KA-9188。     

Influence of TESPT content on crosslink types and rheological behaviors of natural rubber compounds reinforced with silica

Rheological behaviors in the rheographs and crosslink types of silica‐filled natural rubber compounds with differing contents of silane coupling agent were investigated. Bis‐(3‐(triethoxysilyl)‐propyl)‐tetrasulfide (TESPT) was used as a silane coupling agent. In the rheographs of the silica‐filled compounds containing TESPT, the local minimum torque regions after the maximum torque were observed, and the time to reach the local minimum torque was found to become faster with increase of the TESPT content. The reversion ratio, on the whole, was decreased by increasing the TESPT content. By increasing the TESPT content, the crosslink densities of the mono‐, di‐, and polysulfides were increased. Ratio of the polysulfides of the total crosslink density increased, while those of the mono‐ and disulfides decreased with increase of the TESPT content. Changes of the crosslink densities after thermal aging were also investigated. The experimental results were explained with the reduction of curatives adsorbed on the silica, increase of sulfur content, and crosslink formation between the silica and rubber by adding TESPT. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

浅谈单相异步电动机的反转

单相异步电动机是由单相交流电源供电的旋转电机，其定子绕组为单相。当接入单相交流电时，它在定转子气隙中会产生一交变脉动磁场，所以单相异步电动机不能自启动。为了使单相异步电动机自启动，就要在启动时产生一个旋转磁场。本文以电容分相式单相异步电动机为例，介绍单相异步电动机的反转。要使单相异步电动机反转，关键在于改变旋转磁场的旋转方向，但又不能像三相异步电动机那样靠掉换两根电源线来实现。本文结合电容分相式单相异步电动机的具体电路形式，讨论了使其反转的三种方法，经实验验证。确实可行。     

用广义逆法解决摄影测量系统的非线性问题

为了提高双CCD摄影测量系统对大口径且具有反射表面物体的近场三维测量精度,提出用最小二乘广义逆法解决成像系统的非线性问题,分析比较了用最小二乘广义逆法和Levenberg-Marquart2种方法解决成像系统的非线性问题,并采用投影生成特征点法,对圆抛物面形卫星天线进行测量,重构其面形。实验表明,该系统操作简单、实用性强,消除系统的非线性问题后,测量精度提高20%,测得面形与理论面形相当吻合,可用于大型物体的面形测量。针对被测物具体条件,选择合适的算法消除系统的非线性问题及合适的光照条件有助于提高系统性能及其实用性。