共查询到20条相似文献,搜索用时 78 毫秒
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采用橡胶加工分析仪(RPA2000)、差示扫描量热仪(DSC)研究了填料对丁腈橡胶(NBR)硫化性能和动态性能的影响。研究表明,炭黑对NBR的硫化起促进作用,提高了硫化程度,减少了硫化时间;而TiO2对NBR硫化反应具有明显的延迟作用,硫化反应温度提高约20℃。在NBR硫化胶中,炭黑网络结构较强,应变增加,复合材料呈现较强的"Payne"效应,弹性模量和损耗模量随温度升高或频率降低下降幅度较大;TiO2在NBR中基本不形成填料网络,复合材料的弹性模量和损耗模量受温度、应变和频率的影响较小,与纯NBR变化相似。 相似文献
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硫化体系对动态硫化NBR/PA6热塑性硫化胶性能的影响 总被引:1,自引:0,他引:1
采用动态硫化法制备NBR/聚己内酰胺(PA6)热塑性硫化胶(TPV),研究硫化体系对其性能的影响.结果表明:与硫化剂HVA-2/促进剂DM硫化体系相比,采用硫化剂SP-1045/促进剂氯化亚锡硫化体系制备NBR/PA6TPV的加工性能和物理性能较好,且体系中PA6结晶度较小;当硫化剂HVA-2/促进剂DM并用比为1.95/0.49或硫化剂SP-1045/促进剂氯化亚锡并用比为2.6/0.32时,制备NBR/PA6 TPV的NBR分散相粒径较小、分散较均匀和综合物理性能较好. 相似文献
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研究了橡胶型乙烯醋酸乙烯酯共聚物(EVM)/NBR共混比、硫黄和叔丁基酚醛树脂(2402树脂)硫化体系对共混物性能的影响,并对比了动态硫化和静态硫化共混物在性能上的差异。试验结果表明,EVM/NBR共混比显著影响共混物的力学性能,而采用NBR预先动态硫化的方法后,共混物胶料的挤出口型膨胀率明显减小,老化性能得到改善,同时减弱了硫黄和2402树脂等硫化体系对EVM硫化的影响,使多种硫化体系可以共存于共混物中。DSC分析表明EVM/NBR动态硫化共混物只有一个玻璃化温度,且介于EVM和NBR之间,说明EVM和NBR具有良好的相容性。 相似文献
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研究三种硫化体系对NBR/HNBR并用胶性能的影响;结果表明,TT+DTDM共硫化体系胶料的焦烧时间短,DCP+TAIC共硫化体系胶料的焦烧时间稍长,加工安全性好,DCP+S共硫化体系胶料的正硫化时间最小,可缩短生产周期;DCP+S共硫化体系胶料的拉伸强度、伸长率最大,TT+DTDM共硫化体系胶料的撕裂强度最大;DCP+TAIC共硫化体系胶料的综合性能最好,其硬度、拉伸强度、伸长率及撕裂强度分别为74、15.9MPa、281%及35.27kN/m,老化后的拉伸强度变化率、伸长率变化率分别为+10.8%、-5.7%;经高温试验油浸泡后,拉伸强度变化率、伸长率变化率及体积变化率分别为+9.6%、-6.0% and-4.34%,压缩永久变形为17.9%。 相似文献
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The effect of vulcanization temperature (150°–180°C) on the structure and technical properties of gum natural rubber vulcanizates with four different 2-(morpholinodithio)-benzothiazole: sulphur ratios (A, 0.6:2.4; B, 1.5:1.5; C, 2.4:0.6; D, 3.0:0.0) at the respective optimum cure times has been determined. The influence of cure temperature on (a) the chemical crosslink density; (b) the distribution of crosslink types; (c) the extent of sulphidic main chain modifications and (d) the zinc sulphide formation was investigated. Results show that elevated cure temperatures produce a network with lower crosslink density, in particular a lower polysulphidic crosslink density. The formation of intramolecular sulphidic groups and zinc sulphide increase with increasing cure temperatures. The possibility of chain scission during vulcanization, as examined by a quantitative analysis of the sol—gel data, was found to be negligible. The network results have been correlated with the technical properties. 相似文献
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研究偶联剂Si69和KH-550与混炼工艺对炭黑填充NBR胶料硫化特性、表观交联密度、物理性能和动态性能的影响。结果表明,偶联剂的加入能够延长胶料的t90,经高温混炼后的NBR胶料的焦烧时间缩短,t90延长;偶联剂能够增大NBR胶料的表观交联密度和炭黑-橡胶间的相互作用,经高温混炼后作用更加明显,硫化胶的物理性能提高;加入偶联剂KH-550并经高温辊改性后的NBR硫化胶具有更好的耐热老化性能。偶联剂Si69或KH-550能够改善NBR硫化胶的动态性能,加入偶联剂KH-550并经高温改性后性能较佳。 相似文献
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采用常规硫化体系(CV)、半有效硫化体系(SEV)和有效硫化体系(EV)制备了不同的NR(天然橡胶)硫化胶。着重探讨了不同硫化胶的微观形貌、200%定伸强度、撕裂强度、拉伸强度、断裂伸长率和交联密度。研究结果表明:SEV硫化胶的微观形貌相对较好,填料能均匀分散在基体中;在其他条件保持不变的前提下,当w(NOBS)=w(硫)=2.0%(相对于NR质量而言)时,相应的未老化SEV硫化胶的撕裂强度(78 kN/m)相对最大;SEV硫化胶的交联密度大于CV硫化胶和EV硫化胶,并且适当增加交联密度能有效提高其综合性能,从而为开发新一代轮胎等复合材料奠定了基础。 相似文献
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A change in the degree of vulcanization in a carbon black-filled rubber is shown not to affect the change of in-phase shear modulus with strain amplitude, provided the amount of filler is kept constant. Similar results are found with the change of out-of-phase modulus and phase angle with strain amplitude. A similar value of change of in-phase shear modulus with strain amplitude (G′0 – G′∞) is found for a vulcanized and unvulcanized tire tread rubber; this behavior is attributed for the breakdown of the secondary three-dimensional carbon black aggregated network. Detailed consideration is given to other factors such as hydrodynamic, shape factor, and relaxation effects which contribute to the difference between the shear modulus of the gum rubber and the filled rubber when all the carbon black structure has been broken down. The consequence of the breakdown of the secondary aggregated structure of carbon black are considered in terms of factors affecting heat build-up in tires. 相似文献