共查询到19条相似文献,搜索用时 109 毫秒
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对AR-840丙烯酸酯橡胶硫化胶做了五种温度下的热空气和橡胶用3号标准油中的长期老化研究。测定多种性能的变化规律,得到了老化动力学变化曲线。对压缩永久变形和压缩应力松弛性能指标进行经验直线化外推估算,得出特定温度下的性能随老化时间变化的动力学经验估算方程。 相似文献
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采用无喷霜硫黄硫化体系,考察了硫黄用量对三元乙丙橡胶(EPDM)/白炭黑(WCB)混炼胶硫化特性及硫化胶物理机械性能、耐热老化性能、动态力学性能和压缩永久变形的影响。结果表明,在硫黄用量为0.5~1.5份的条件下,随着硫黄用量的增加,EPDM/WCB混炼胶的硫化速率减慢,硫化胶的拉伸强度先升高后下降,当硫黄用量为1.00份时达到最大值(22.4 MPa),同时扯断伸长率和永久变形逐渐下降,邵尔A硬度升高;热空气老化后,硫化胶的拉伸强度、撕裂强度和硬度均提高,但扯断伸长率下降幅度较大;随着硫黄用量的增加,硫化胶的玻璃化转变温度向高温方向移动,损耗因子峰值先升高后下降,储能模量增大,压缩永久变形略有减小。 相似文献
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低苯基硅橡胶压缩永久变形性能的研究 总被引:1,自引:0,他引:1
比较了不同捏合工艺下热硫化低苯基硅橡胶的压缩永久变形性能。发现捏合时间对低苯基硅橡胶的压缩永久变形性能有显著影响。随着捏合时间的延长,压缩永久变形性能先降后增,当捏合时间达到150 min时,压缩永久变形性能趋于稳定;继续延长捏合时间,压缩永久变形性能变大;随着热空气老化温度的升高,低苯基硅橡胶的压缩永久变形变大,在300℃×12 h条件下压缩永久变形可达100%,基本丧失了回弹能力;随着热空气老化时间的增加,低苯基硅橡胶压缩永久变形变大,在200℃×1 200 h、250℃×72 h、300℃×12 h老化后,低苯基硅橡胶的压缩永久变形达到100%,基本丧失了回弹能力。 相似文献
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对AR-840丙烯酸酯橡胶硫化胶做了五种温度下的热空气和橡胶用3号标准油中的长期老化研究,测定多种性能的变化规律,得到了老化动力学变化曲线。对压缩永久变形和压缩应力松驰性能指标进行经验直线化外推做算,得出特定温度下的性能随老化时间变化的动力学经验估算方程。 相似文献
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探究了共混比对丙烯酸酯橡胶/丁腈橡胶(ACM/NBR)共混胶的硫化特性、力学性能、耐热老化性能、耐油性能、高温压缩永久变形性能和低温性能的影响。研究表明,采用TCY/S/促进剂的硫化体系时,在ACM中并用少量的NBR可以显著地提高硫化速度,最高扭矩也随着NBR用量的增加而增加,并用5 phr NBR后,共混硫化胶的拉伸强度与纯ACM硫化胶相比,提高了近17%,但NBR的并用量由5 phr增加到25 phr时,硫化胶的力学性能变化不大。随着NBR用量增加,共混硫化胶的耐热老化性能和耐油性能均变差,但高温压缩永久变形减小,耐寒性有较大改善。 相似文献
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对40000m^3/h空分装置内、外压缩流程进行了热力计算,对比了外压式、半内压式、全内压式流程所需功耗的高低,分析了产品能耗指标的影响因素,根据不同装置的实际情况,对压缩流程进行了优化选择。 相似文献
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通过对40000m3/h空分装置内外压缩流程热力计算,分析外压式、半内压式、全内压式流程所需功耗的高低和影响产品的能耗指标的因素,并结合用户实际情况,对压缩流程作出最佳选择,即:流程最实用,能耗较低。通过计算和实际情况证明,内压缩流程通过合理的组织,能耗已越来越低。 相似文献
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随着煤化工行业的持续发展,其对空分装置安全性能的要求不断提高。通过对外压缩和内压缩流程的安全性能进行比较,可以看出内压缩比外压缩具有明显优势。 相似文献
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EPDM的压缩永久变形性能研究 总被引:1,自引:0,他引:1
研究了硫化体系、填充体系、增塑体系和硫化时间对EPDM高温下压缩永久变形的影响。实验结果表明:在硫黄、过氧化物、酚醛树脂3种硫化体系中,过氧化物配合助交联剂(TAIC)硫化的EP—DM压缩永久变形最小,硫磺硫化体系硫化胶则最大;胶料的压缩永久变形随着炭黑类填料用量的增加而降低,却随着无机类填料用量的增加而增加;填充具有高结构、适当粒径的炭黑(如N550)并适当延长硫化时间能有效降低EPDM的压缩永久变形。 相似文献
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NBR/EPVC共混物压缩永久变形的研究 总被引:2,自引:1,他引:2
研究了聚氯乙烯糊树脂(EPVC)用量、增塑剂DOP用量、硫化体系、交联剂DCP用量、补强剂品种对NBR/EPVC共混物压缩永久变形的影响。结果表明,加入EPVC使NBR/EPVC共混物的压缩永久变形显著增大;DOP也会使共混物的压缩永久变形增大;采用过氧化物硫化体系、半有效硫化体系和有效硫化体系硫化的NBR/EPVC共混物压缩永久变形较小,在半有效硫化体系中加入交联剂DCP可进一步降低共混物的压缩永久变形;采用炭黑补强的NBR/EPVC共混物压缩水久变形比采用自炭黑补强的小。 相似文献
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Robert Erickson 《Drying Technology》2013,31(8):1943-1961
ABSTRACT Matched units of 3.2 cm thick red oak lumber were dried simultaneously in a steam heated and dehumidification kiln. The two pairs of runs are designated Set I and Set II. The objective was to compare the mechano-sorptive behavior and board shrinkages while using the recommended U.S. Forest Products Laboratory schedule with the steam kiln and comparatively low temperature drying in the dehumidification kiln. Drying rates in Set I and Set II were comparable for the two kilns up to approximately 450 hours, which illustrated the dependence of the drying rate on the relative humidity of the kiln air rather than its temperature. Subsequently, the stepwise increases in dry bulb temperature for the steam kiln were accompanied by accelerated drying. Less compression set developed in the interior mechano-sorptive slices for the dehumidification kiln runs. On an average, the maximum compression set for the core slices from the dehumidification kiln was about S0% of that for core slices from the steam heated kiln. Simultaneously the surface slices from the dehumidification kiln developed more tension set than those from the steam heated kiln. Board width shrinkage at the end of drying, at the same average moisture content, was greatest for the steam kiln. The greater shrinkage is attributed to greater compression set due to the higher drying temperatures. These results support McMillen)s explanation for the effect of drying temperatures upon sets and the shrinkage of red oak lumber. 相似文献
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In this article, mechanical and compression set properties, swelling property, and stress–strain behavior during compression of polysulfide sealants based on different polysulfide resin were investigated. The results showed that molecular weight and cross‐linking agent of liquid polysulfide resin had significant influence on mechanical and compression set properties of the sealants. The sealants based on higher molecular weight polysulfide resin had higher mechanical properties. At the same time, lower cross‐linking agent in polysulfide resin produced lower cross‐link density and higher swelling property, which resulted in higher compression set value of the sealant. However, when different molecular weight polysulfide resins were used in the sealant simultaneously, the testing results indicated that the compression performance of the sealants was significantly enhanced, while mechanical properties of the sealants kept nearly unchanged. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
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采用高聚合度PVC与增塑剂等共混,复配制行了PVC热塑性弹性体(TPVC)对TPVC的冲击回弹性和压缩性能进行了研究。结果表明,当弹性体的压缩应变在20%~25%;压缩永久变形率在5%以下时,TPVC比压强度为3.85~5.45MPa(橡胶为1.22~1.78MPa)是橡胶的3倍左右。 相似文献