共查询到17条相似文献,搜索用时 62 毫秒
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研究了环氧化天然橡胶的塑炼,混炼,挤出及加工流变性能。结果表明,ENR的加工性能与天然橡胶相近,只是塑炼效果胶NR稍差。ENR混炼生热较低,吃粉速度较快,虽然挤出口型膨胀率大于NR,但挤出物外观与NR相当。 相似文献
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对天然胶乳及生胶所制备的硫化胶进行网络结构和性能测试 ,考察不同加工方法对硫化胶结构与性能影响。结果表明 ,胶乳胶膜的交联速率、效率、硫化胶强度及耐老化性能都比相应干胶的大 ;对普通硫化体系 ,生胶硫化胶的单、双硫键密度占总交联键密度的比例随硫化时间的延长有较大幅度增加 ,而配合胶乳胶膜的则变化不明显。 相似文献
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采用酶辅助微生物凝固鲜胶乳提高天然橡胶产品性能,探究了酶用量对天然橡胶理化指标、硫化特性、加工性能、力学性能、机理及生热性能的影响。结果表明,随着酶用量的提高,生胶塑性初值和门尼黏度升高,塑性保持率降低;硫化胶正硫化时间(t90)和焦烧时间(t10)变短;生胶的弹性模量(G′)高,损耗因子(tan δ)小;硫化胶的拉伸强度、100%定伸应力及撕裂强度均呈上升趋势,老化处理后,硫化胶的力学性能同样保持升高的趋势;同时硫化胶温升呈下降趋势;此外,氮含量和凝胶含量有降低趋势,而丙酮溶物含量有升高趋势。 相似文献
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微生物凝固天然橡胶与酸凝固天然橡胶的性能差异 总被引:5,自引:1,他引:5
为揭示微生物凝固天然橡胶(NR-w)和酸凝固天然橡胶(NR-a)的性能差别,制备了3个系列的NR,并对其性能进行了全面的研究.结果发现,在生胶性能方面,NR-w凝胶含量和塑性初值均高于NR-a,而分子量低于NR-a.对于硫化胶,NR-w纯胶硫化胶的力学性能远高于NR-a纯胶,而NR-w炭黑胶的力学强度与NR-a炭黑胶很接近;此外,NR-a纯胶的抗老化性能远高于NR-w,其炭黑胶的抗老化性能也高于NR-w,在硫化性能方面,NR-w的转矩增大速率快于NR-a,强度也比NR-a高.在动态性能方面,NR-w的抗湿滑性能和滚动阻力均高于NR-a. 相似文献
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Studies were performed on the nature and magnitude of the variabilities in the rheological and processing properties of purified natural rubber (PNR). PNR samples were prepared from three clones of NR (RRIM 600, GT 1, and KRS 156). The corresponding whole NR (WNR) containing total nonrubber substances was also prepared for comparative purposes. All samples were stored for 3 months to elucidate the effect of storage on their rheological and processing properties. A novel study was also conducted to determine whether the commonly reported variabilities in the rheological properties had actual effects on the mixing. These were studied by means of an instrumented torque rheometer fitted with a small mixer head. The results showed that the vulcanization time of PNR was consistent and did not show clonal variation. PNR exhibited large clonal variation in the viscosity at a low shear rate and storage hardening, similar to the ordinary NR. However, the variations in the viscosity of PNR became less evident as the shear rates increased toward 200 s?1. The significant findings were that the observed variations in the rheological properties had no practical effect on the mixing time of PNR samples with carbon black. Moreover, the PNR samples required less energy for mixing than their WNR counterparts. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 456–465, 2005 相似文献
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《应用化工》2022,(5)
采用单独含有NH_3、HY的天然橡胶作为对照样,与含有复合保存剂HY/NH_3的天然橡胶进行性能比较,利用红外光谱仪测定天然橡胶结构,橡胶加工分析仪测定其加工性能,核磁共振交联密度仪测其交联密度,研究复合保存剂HY/NH_3对天然橡胶性能的影响。结果表明,HY/NH_3几乎不影响生胶结构;在应变、温度扫描环境下,NY-1的弹性模量G’最大,损耗因子tanδ最小,NY-3居中;在频率扫描环境下,NY-3的弹性模量G’最大,损耗因子tanδ居中,NY-1的弹性模量G’居中,损耗因子tanδ最小;三种扫描环境下,NY-2的弹性模量G’均最小,损耗因子tanδ均最大;老化前,复合保存剂样品的总交联密度小于NH_3、HY样品的总交联密度;老化后,所有样品的总交联密度均变小。 相似文献
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In this study, the influence of the processing conditions and the addition of trans-polyoctenylene rubber (TOR) on Mooney viscosity, tensile properties, hardness, tearing resistance, and resilience of natural rubber/styrene–butadiene rubber blends was investigated. The results obtained are explained in light of dynamic mechanical and morphological analyses. Increasing processing time produced a finer blend morphology, which resulted in an improvement in the mechanical properties. The addition of TOR involved an increase in hardness, a decrease in tear resistance, and no effect on the resilience. It resulted in a large decrease in the Mooney viscosity and a slight decrease in the tensile properties if the components of the compounds were not properly mixed. The results indicate that TOR acted more as a plasticizer than a compatibilizer. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 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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将碳纳米管(CNTs)添加到天然橡胶(NR)中制备了CNTs/NR复合材料,考察了CNTs的管径和用量对复合材料硫化特性、力学性能、动态力学性能和分散性的影响。结果表明,在管径相同时,随着CNTs用量的增大,复合材料的正硫化时间延长。随着CNTs用量的增大,复合材料的拉伸强度和扯断伸长率先增大后减小。相同管径件下,CNTs的用量越大,Payne效应越强,储能模量变化越大,损耗因子也越大;而在相同用量下,CNTs的管径越大,Payne效应越弱,储能模量变化越小,损耗因子也越小。当CNTs用量为15份、管径为80 nm时,其在NR基体中的分散性最好,复合材料的综合力学性能及动态力学性能最佳。 相似文献
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Ekwipoo Kalkornsurapranee Wanida Yung-Aoon Ladawan Songtipya Jobish Johns 《塑料、橡胶和复合材料》2017,46(6):258-265
The process ability of vulcanising natural rubber using glutaraldehyde at low temperature has been studied. The main objective of this work is to improve the properties and stability of natural rubber (NR) using glutaraldehyde as a curing agent. In this study, the vulcanised samples were prepared systematically and compared with sulphur cured natural rubber vulcanisates. The influence of mole ratio of ammonia and glutaraldehyde, and the processing parameters (i.e. curing time and temperature) was investigated. The cured NR based on glutaraldehyde exhibited better hardness and thermal properties than that of the NR cured from conventional sulphur system. The experimental results reveal that the properties of glutaraldehyde cured NR can be developed with the proper additives combination and conditions adopted in the preparation. This cured system is very interesting due to it can be used for high temperature industrial applications. Moreover, it eases of processing at low temperature and cost. 相似文献