反式-1，4-聚异戊二烯硫化胶及其共混硫化胶的研究

研究了反式－１，４－聚异戊二烯（ＴＰＩ）硫化胶及其与ＢＲ，ＳＢＲ，ＮＲ共混硫化胶的性能。结果表明，通过控制硫黄用量即交联密度，可使ＴＰＩ硫化胶具有优异的力学和动态力学性能；ＴＰＩ与ＢＲ，ＳＢＲ，ＮＲ共混，工艺性能良好，当ＴＰＩ／ＢＲ，ＴＰＩ／ＳＢＲ和ＴＰＩ／ＮＲ共混比小于５０／５０时，共混硫化胶的力学和动态力学性能优于ＢＲ，ＳＢＲ和ＮＲ硫化胶，特别是拉伸疲劳寿命大大延长，这正是高性能轮胎所需要的     

NR/NBR/氯醚橡胶三元共混物性能的研究

采用双硫化体系,制备了ＮＲ／ＮＢＲ／氯醚橡胶（ＣＯ）三元共混硫化胶,并对硫化胶的性能进行了测试。实验结果表明：采用促进剂ＮＡ２２／硫黄／氧化锌硫化体系可实现共混物的同步硫化;ＣＯ对ＮＲ的性能有较大的影响,少量的ＣＯ可有效地提高ＮＲ的耐老化、耐介质和气密性,但共混物的耐水性能比ＮＲ略有下降。     

不同共混比Ln—BR／NR的性能

研究了稀土顺丁橡胶（Ｌｎ－ＢＲ）与天然橡胶（ＮＲ）以不同比例共混后生胶、混炼胶和硫化胶的性能，并与相同条件下的镍系顺丁橡胶（Ｎｉ－ＢＲ）／ＮＲ共混胶的性能进行了对比，结果表明，共混胶随Ｌｎ－ＢＲ用量的增大，ＭＬ＾１００℃１＋４降低，工艺行为良好，硫化胶力学性能、磨耗、湿滑指数和生热值下降，并且Ｌｎ－ＢＲ／ＮＲ硫化胶的抗湿滑性和动态疲劳性均优于Ｎｉ－ＢＲ／ＮＲ硫化胶。     

氯化丁基橡胶/天然橡胶共混物性能的研究

研究了共混比及硫化体系对氯化丁基橡胶（ＣＩＩＲ）／天然橡胶（ＮＲ）共混物性能的影响，探讨了老化温度及防老剂对氧化锌／促进剂ＴＭＴＤ／促进剂ＤＭ硫化体系硫化的ＣＩＩＲ／ＮＲ共捐物耐热氧老化性能的影响。试验结果表明，氧化锌／促进剂ＴＭＴＤ／促进剂ＤＭ（５．０／１．５／１．０）硫化体系硫化的ＣＩＩＲ／ＮＲ共混物的拉伸强度和扯断伸长率与按共混比计算的平均值差别较小，尤其是拉伸强度与计算值完全一致。当共混物中ＣＩＩＲ用量超过５０份时，共混物的耐热氧老化性能明显改善。不同防老剂对ＣＩＩＲ／ＮＲ（５０／５０）共混物热氧老化的防护效能大小顺序为ＲＤ及４０１０＞４０１０ＮＡ＞ＭＢ＞Ｄ。防老剂ＲＤ先加入到ＮＲ中后再与ＣＩＩＲ共混．其防护效能更佳。     

稀土BR／SBR共混胶的性能

研究了４种共混比的ＬｎＢＲ／ＳＢＲ共混生胶、混炼胶及硫化胶的性能，并与ＮｉＢＲ／ＳＢＲ共混胶进行了对比。结果表明，共混生胶的ＭＬ均低于ＬｎＢＲ及ＳＢＲ；当ＬｎＢＲ／ＳＢＲ共混混炼胶的ＭＬ、剪切应力、出口膨胀及硫化速度均低于ＮｉＢＲ／ＳＢＲ共混胶，挤出物外观优于后者；共混硫化胶的拉伸强度、热空气老化、拉伸疲劳、湿滑、耐磨等性能均明显优于后者，生热和透气率高于后者。     

PVC／ENR／XNBR（NBR）动态硫化共混物

能干不氧化天然橡胶（ＥＮＲ）、聚氯乙烯（ＰＶＣ）和羧基丁腈橡胶（ＸＮＢＲ）之间的自硫化反应，实现了ＰＶＣ／ＥＮＲ／ＸＮＢＲ三元共混物的动态友化，由此得到了具有热塑性弹性体的一些典型特征的ＰＶＣ／ＥＮＲ／ＸＮＢＲ动态自硫化共混物。该人混物与自硫化反应不明显的ＰＶＣ／ＥＮＲ／ＮＢＲ共混物进行了比较，发现动态自硫化反应显著提高了共混物的综合性能。结果表明，当橡塑比为７０／３０时，前者的拉伸强度为１１．８     

PVC／SBR热塑性弹性体的研制

以ＡＢＳ、氯丁橡胶（ＣＲ）、马来酸酐（ＭＡ）接枝ＳＢＲ（ＳＢＲ－ＭＡ）作增容剂对ＰＶＣ／ＳＢＲ的共混比、增容剂、增塑剂用量做了优化选择。同时对动态硫化ＰＶＣ／ＳＢＲ的硫化体系、硫化工艺条件进行了探讨,并比较了动态硫化对共混体性能的影响。结果表明：ＰＶＣ／ＳＢＲ为８０／２０,增容剂ＡＢＳ／ＳＢＲ－ＭＡ为５／５时,选用半有效硫化体系,１６５℃下动态硫化６ｍｉｎ,共混物综合性能最佳     

普通、半有效和有效硫化体系的NR/BR共混胶料的疲劳寿命曲线方程*

研究了采用普通、半有效和有效硫化体系的ＮＲ／ＢＲ（共混比为７０／３０）硫化胶在同一表观交联密度下的疲劳寿命,比较了３种硫化体系硫化胶的疲劳特征参数β和Ｃ０值,并采用指数函数模型拟合出３种硫化体系硫化胶的疲劳寿命ＳＮ曲线方程,其中最大相对偏差只有－６５２％,相关系数均大于０９５３５,可较好地描述不同硫化体系的ＮＲ／ＢＲ共混胶料的动态疲劳过程。     

EVM/NBR动态硫化共混物性能的研究

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。     

不同添加剂对自硫化CSM/XNBR共混物性能的影响

在没有任何硫化剂的条件下,氯磺化聚乙烯（ＣＳＭ）和羧基丁腈橡胶（ＸＮＢＲ）的共混物（质量比１∶１）能在１８５℃×６０ｍｉｎ下模压硫化。溶胀分析、凝胶测定、硫化曲线及红外谱图分析证实了ＣＳＭ中的氯磺酰基和ＸＮＢＲ中的羧基之间发生了交联反应。共混体系能用５０份炭黑增强,３０份氯化石蜡增塑。加入ＣＳＭ的稳定剂增加了共混硫化胶的凝胶质量分数。碱性物质能大幅度提高自硫化ＣＳＭ／ＸＮＢＲ共混物的强度。共混物的耐热氧老化性能尚待提高。     

铁系乙烯基丁二烯橡胶/天然橡胶共混物的性能

研究了铁系乙烯基丁二烯橡胶(FVBR)与天然橡胶(NR)以50/50(质量比)共混硫化胶的物理机械性能和黏弹特性,并与溶聚丁苯橡胶(SSBR)与NR共混胶进行了对比。结果表明,FVBR与NR有良好的相容性,共混胶只存在1个玻璃化转变温度。FVBR/NR的混炼行为良好,但必需添加操作油,否则难以获得理想的硫化胶性能。FVBR/NR与SSBR/NR相似,不仅具有良好的拉伸和撕裂性能,而且具有高抗湿滑性;其生热和滚动阻力以及热老化性能优于后者,但耐磨性略逊于SSBR/NR。     

硫化时间对绿色轮胎胎面胶交联网络结构与性能的影响

针对以溶聚丁苯橡胶(SSBR)/顺丁橡胶(BR)并用胶为主体材料的绿色轮胎胎面胶,研究在不同硫化时间下未填充白炭黑的SSBR/BR并用胶(简称未填充白炭黑体系胶料)及填充白炭黑的SSBR/BR并用胶(简称填充白炭黑体系胶料)形成的交联网络结构与性能变化。结果表明:对于未填充白炭黑体系胶料,随着硫化时间的延长,硫化胶的交联密度略有降低,硬度、定伸应力、拉伸强度和回弹值等变化不大,撕裂强度提高,拉断伸长率和耐伸张疲劳性能降低;对于填充白炭黑体系胶料,随着硫化时间的延长,硫化胶的填料网络结构化程度逐渐提高,交联密度略有增大,键能较低的多硫键减少,键能较高的单硫和双硫键增多,硫化胶的拉伸强度、回弹值、耐伸张疲劳性能和耐磨性能基本不变,生热和滚动阻力降低;未填充及填充白炭黑体系硫化胶的耐老化性能均随硫化时间的延长而逐渐提高,这表明以SSBR/BR并用胶为主体材料的胎面胶即使在高温下硫化较长时间,仍具有较好的性能。     

炭黑在天然橡胶/溶聚丁苯橡胶硫化胶中的分散及其对性能的影响

考察了溶聚丁苯橡胶(SSBR)用量、炭黑的种类及用量对天然橡胶(NR)/SSBR硫化胶动态力学性能和力学性能的影响.结果表明,炭黑与SSBR的结合作用比与NR弱;随SSBR用量的增加,炭黑在NR/SSBR共混硫化胶中的分散性提高,Payne效应减弱,频率敏感性增强;随SSBR用量的增加,NR/SSBR共混硫化胶的拉伸强度和撕裂强度减小,扯断伸长率变化不大;而定伸应力则呈先减小后增大的趋势;随不同种类的炭黑在NR/SSBR硫化胶中分散性的提高,定伸应力呈上升趋势,损耗因子和压缩生热呈减小趋势.     

低滞后炭黑DZ13对胎面胶物理性能及疲劳破坏行为的影响

采用以天然橡胶(NR)、NR/顺丁橡胶(BR)和NR/BR/溶聚丁苯橡胶(SSBR)为基体的轮胎胎面胶配方,研究低滞后炭黑DZ13对3种硫化胶物理性能和疲劳破坏行为的影响。结果表明:低滞后炭黑DZ13部分替代炭黑N234后,NR,NR/BR和NR/BR/SSBR硫化胶的物理性能变化规律相似,即定伸应力略有增大、拉断伸长率和撕裂强度减小;耐磨性能、耐压缩疲劳性能和耐割口增长性能的变化依赖于基体橡胶;其中NR/BR硫化胶的屈挠疲劳次数提高,但疲劳破坏界面的微观形貌更加粗糙。     

Fly‐ash particles and precipitated silica as fillers in rubbers. II. Effects of silica content and Si69‐treatment in natural rubber/styrene–butadiene rubber vulcanizates

This article explored the possibility of using silica from fly‐ash particles as reinforcement in natural rubber/styrene–butadiene rubber (NR/SBR) vulcanizates. For a given silica content, the NR : SBR blend ratio of 1 : 1 (or 50 : 50 phr) exhibited the optimum mechanical properties for fly‐ash filled NR/SBR blend system. When using untreated silica from fly‐ash, the cure time and mechanical properties of the NR/SBR vulcanizates decreased with increasing silica content. The improvement of the mechanical properties was achieved by addition of Si69, the recommended dosage being 2.0 wt % of silica content. The optimum tensile strength of the silica filled NR/SBR vulcanizates was peaked at 10–20 phr silica contents. Most mechanical properties increased with thermal ageing. The addition of silica from fly‐ash in the NR/SBR vulcanizates was found to improve the elastic behavior, including compression set and resilience, as compared with that of commercial precipitated silica. Taking mechanical properties into account, the recommended dosage for the silica (FASi) content was 20 phr. For more effective reinforcement, the silica from fly‐ash particles had to be chemically treated with 2.0 wt % Si69. It was convincing that silica from fly‐ash particles could be used to replace commercial silica as reinforcement in NR/SBR vulcanizates for cost‐saving and environment benefits. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Hydrogenated natural rubber blends: Aspect on thermal stability and oxidative behavior

Hydrogenated natural rubber (HNR) prepared from natural rubber (NR) is a new sustainable elastomer with excellent thermal properties. This study reports on the effect of vulcanization system and blend ratio on the thermal and oxidative resistance of HNR/NR vulcanizates. The various HNR/NR ratios vulcanized by peroxide and sulfur donor system exhibited the highest retention of tensile strength after thermal aging due to the formation of zinc‐dimethyldithiocarbamate (ZDMDC) which is an efficient antioxidant. The results from thermogravimetric analysis (TGA) indicated that the saturated structure of HNR had higher decomposition temperature and activation energy to enhance the thermal stability of HNR/NR vulcanizates. The initial and maximum decomposition temperatures of NR and HNR phases in vulcanizates were not affected by rubber blend ratio. This suggests that the decomposition pattern of HNR has no influence on another constituent. The increase in HNR content in the blends could retard the ozonolysis resulting in the surface cracking attacked by ozone. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Blending of NR/BR/EPDM by reactive processing for tire sidewall applications. III. Assessment of the blend ozone‐ and fatigue‐resistance in comparison with a conventional NR/BR compound

The NR/BR blend compound formulations for tire sidewall applications contain a set of stabilizers added to prevent degradation mainly due to oxygen, ozone, and heat. 6PPD is the most effective and widely used antiozonant in tire compounds, but is a highly staining material causing a surface discoloration of the tire sidewall. Incorporation of 30 phr EPDM into blends of NR/BR improves the ozone resistance to the required level, without the need of 6PPD. The first two parts of this series have described a reactive processing technique applied to enhance the covulcanization and blend homogeneity, together with their characterization. In the present article, the properties of the NR/BR/EPDM blends prepared by both reactive and straight mixing are tested in comparison with those of equivalent conventional NR/BR compounds. The reactive NR/BR/EPDM blend vulcanizates show excellent tensile strength, elongation at break, tear strength, fatigue‐to‐failure, and ozone resistance in both static and dynamic conditions. The properties are equivalent or even superior to those of the conventional NR/BR tire sidewall compounds. The simple straight mixed NR/BR/EPDM blend vulcanizates distinctively possess inferior mechanical properties compared to those of the reactive mix. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2555–2563, 2007     

Reclaiming of ground rubber tire by a novel reclaiming agent. I. virgin natural rubber/reclaimed GRT vulcanizates

Mechanochemically devulcanized ground rubber tire (GRT) was (re)vulcanized in compositions with virgin natural rubber (NR). The NR/GRT (re)vulcanizates with GRT content from 20 to 60 wt% have been prepared and studied. Reclaiming of GRT was successfully carried out by tetra methyl thiuram disulfide (TMTD) in presence of spindle oil at around ambient temperature. The cure characteristics and mechanical properties of the virgin NR/reclaim GRT blend were studied. The optimum cure time decreases but scorch time remain unaltered with increasing reclaim rubber content in the blend. Effect of carbon black was studied in NR/RR (80/20) blend. Ageing characteristics of different NR/RR blends were evaluated. Scanning electron microscopy (SEM) studies further indicate the coherency and homogeneity in the NR/RR vulcanizate. The dynamic mechanical properties and swelling behavior of NR/RR blend vulcanizates were examined. The elastic and storage modulus of the NR/RR vulcanizates become improve with increasing reclaim rubber content. Electrical properties of NR/RR vulcanizates were also studied. POLYM. ENG. SCI., 47:1091–1100, 2007. © 2007 Society of Plastics Engineers     

白炭黑用量对氯丁橡胶/天然橡胶共混物性能的影响

研究了不同用量的沉淀法白炭黑填充质量比75/25的氯丁橡胶/天然橡胶共混物的物理机械性能、耐热老化性能和耐油性能,并用扫描电镜研究了共混物的结构。结果显示,白炭黑的加入改善了共混硫化物的拉伸强度、100%定伸应力和邵尔A硬度。压缩永久变形减小,黏度增大,从而导致在形变的过程中天然橡胶分散相占有率相对减少。相关性能也证明随着白炭黑用量的增加,硫化胶的耐热和耐油性能显著提高。     

NR/EPDM/CR共混物制作高强度胶管配方研制

研究了天然橡胶、三元乙丙胶与氯丁橡胶并用胶的配方和混炼方法.试验结果表明,这三种胶共混,可以采用硫磺和金属氧化物硫化体系.共混物采取NR和EPDM先行配合混炼,在高温下过滤,再与预先加入硫化剂的CR胶按比例掺混、热炼挤出的工艺方法.胶料的硫化速度较快,强度较高,耐臭氧性能和耐介质性能较好;老化性能优良,耐油性能略有下降.