促进剂DPG在白炭黑填充天然橡胶胶料混炼中加料顺序对胶料性能的影响

研究促进剂DPG在白炭黑填充天然橡胶胶料混炼中加料顺序对胶料性能的影响。结果表明：促进剂DPG与NR、白炭黑和硅烷偶联剂同时加入混炼能够参与和促进硅烷化反应,改善白炭黑与NR之间的相容性,减轻白炭黑聚集,因此可降低Payne效应,提高胶料的耐热老化性能,但因其参与硅烷化反应而减小了参与硫化反应的量,导致硫化速率降低,焦烧时间延长,同时由于交联密度下降导致硫化胶的耐磨性能、300%定伸应力和撕裂强度降低及60 ℃时的tanδ增大,因此在配方开发和混炼工艺设计时,应考虑适量补充促进剂DPG在前期混炼阶段加入时的损耗。     

宋汀力车胎混炼胶硫化体系用量评估计算

混炼胶配方硫化体系,包括硫化剂、促进剂品种和用量的确定,对胶料的工艺性能和物理机械性能影响很大,事关重要。涉及混炼胶硫化历程的因素有：焦烧性能（T5）、硫化速率（T90－T10）、正硫化（T90）和硫化曲线平坦性;整体配方设计要考虑：硫化速率匹配、定伸应力匹配和成品硫化程度;成品内在质量使用寿命;生产效率和成本。     

NBR低硫硫化体系的研究

试验研究低硫硫化体系对NBR胶料性能的影响。结果表明，对于低硫硫化体系，单用促进剂不能得到理想的硫化曲线；促进剂并用可提高胶料的抗焦烧性能，且硫化曲线平坦，硫化速度适中。当低硫硫化体系为硫黄0．3，促进剂TMTD1．5，促进剂CZ1，促进剂DTDM0．8，防焦剂CTP1时，NBR胶料的抗焦烧性能明显提高，硫化胶的综合物理性能最优。     

用RPA2000橡胶加工分析仪研究胶料硫化过程中填料的聚集程度

用RPA2000橡胶加工分析仪研究胶料(丁苯橡胶/顺丁橡胶并用胶)硫化过程中填料的聚集程度。结果表明:随着转矩提高,硫化过程中不同配方胶料动态力学性能[储能模量(G′)、损耗模量(G″)和损耗因子(tanδ)]之间的差异增大;随着防焦剂用量增大,促进剂CZ胶料的焦烧时间延长,ΔG′增大,填料聚集程度提高,tanδ随应变增大的增幅增大;迟效型促进剂DZ胶料的焦烧时间较长,硫化速度较慢,在硫化过程中填料聚集时间较长,聚集程度较高,在大应变下tanδ较大;在硫化过程中填料的聚集效应发生在焦烧期和热硫化初期,在保证胶料加工安全性能下,应尽量缩短设计的配方胶料的焦烧时间,提高硫化速度,以降低填料聚集程度。     

促进剂TBSI在NR配方中的应用研究

研究了促进剂TBSI对NR胶料配方性能的影响.结果表明TBSI对NR胶料具有长效焦烧迟延作用和较慢的硫化速率,可有效提高胶料热老化或过硫化状态下的物理机械性能,具有良好的抗硫化返原性能.     

促进剂TBSI在NR配方中的应用研究

研究了促进剂TBSI对NR胶料配方性能的影响。结果表明：TBSI对NMR胶料具有长效焦烧迟延作用和较慢的硫化速率,可有效提高胶料热老化或过硫化状态下的物理机械性能,具有良好的抗硫化返原性能。     

环保型促进剂TBSI在胶料中的应用研究

促进剂TBSI属于伯胺类促进剂,硫化反应时不产生易致癌的亚硝胺。研究环保型促进剂TBSI在胶料中的应用性能和环保性能。结果表明：与促进剂DCBS,TBBS和CBS相比,环保型促进剂TBSI的储存稳定性更好,其胶料的硫化反应活化能更大,焦烧时间更长,加工安全性和抗硫化返原性较好,其更加适用于厚制品,可以替代促进剂TBBS/防焦剂CTP单独使用;促进剂TBSI及其胶料的叔丁胺和挥发性有机化合物的质量分数较小,环保性能更好。     

后效性促进剂对高压胶管胶料性能的影响

分别采用复合硫化体系和低硫高促硫化体系,研究次磺酰胺类促进剂CZ,NS,NOBS和DZ以及噻唑类促进剂M和DM对高压胶管丁腈橡胶(NBR)胶料性能的影响。结果表明:含次磺酰胺类促进剂NBR胶料的综合物理性能、焦烧性能和粘合性能较含噻唑类促进剂NBR胶料好;含噻唑类促进剂NBR胶料的耐油性能与含次磺酰胺类促进剂胶料相当。     

后效性促进剂对高压胶管胶料性能的影响

分别采用复合硫化体系和低硫高促硫化体系,研究次磺酰胺类促进剂CZ,NS,NOBS和DZ以及噻唑类促进剂M和DM对高压胶管丁腈橡胶（NBR）胶料性能的影响。结果表明：含次磺酰胺类促进剂NBR胶料的综合物理性能、焦烧性能和粘合性能较含噻唑类促进剂NBR胶料好;含噻唑类促进剂NBR胶料的耐油性能与含次磺酰胺类促进剂胶料相当。     

促进剂NS的制备及其硫化特性研究

采用过氧化氢氧化法合成产率和纯度较高的N-叔丁基-2-苯并噻唑次磺酰胺(促进剂NS),研究其硫化特性.结果表明,随着硫化温度的升高,NR胶料的ts2和t90缩短,硫化速率常数和硫化强度增大;在143℃下硫化时,NR胶料的MH最大,焦烧安全性较好;胶料在133～173℃时的硫化温度因数为1.97,表观活化能为118.8kJ·mor-1.     

橡胶微观结构对NBR硫化加工特性的影响

研究了丁腈橡胶(NBR)微观结构对NBR及NBR/炭黑混炼胶硫化加工性能的影响.研究表明:丙烯腈含量增加,分子极性增加,物理交联密度增加,致使焦烧时间缩短,正硫化时间先增长后缩短,提高了胶料的加工性能,硫化速度先增加后减小.加入炭黑后,对低丙烯腈含量的NBR1846的硫化转矩影响最大,减小了因丙烯腈含量造成的流变性能的变化,缩短了硫化时间,提高了硫化转矩和硫化程度,但炭黑对NBR的硫化速度影响不明显.     

Characterization of NBR/bentonite composites: vulcanization kinetics and rheometric and mechanical properties

The effect of the incorporation of bentonite (BT) untreated and treated with octadecylamine on the rheological behavior and vulcanization kinetics of NBR was investigated. Mechanical properties were also evaluated. Decreases in the optimum cure time (t ₉₀) and in the scorch time (t _S2) and a notorious improvement in mechanical properties were found when treated BT was employed. From the vulcanization kinetics analysis, we can infer that the curing rate is superior for the treated BT composites, while the reaction orders point out the dependency of the vulcanization reaction on the initial reactants if compared to the catalytic effect of the reaction products.     

Premature vulcanization behaviors of rubber compounds under high shear rates processing

The premature vulcanization behaviors of six kinds of common rubber (NR, BR, SBR, NBR, CR, and EPDM) compounds containing curing agents were studied in a wide processing temperature range (100–140°C) and rotor speed range (30–70 rpm) using a Brabender torque rheometer, which can supply the rubber compounds a high shear rates processing condition. After comparison with the Mooney scorch time (MSt₅), it is shown that Mooney scorch time cannot predict the premature vulcanization time under high shear rate processing. Six models were put forward based on the data obtained from the Brabender mixing head. The regression analysis and variance analysis showed that these models could simulate the premature vulcanization time very well. An explanation was given based on the reactivity and of rubber chain segments: the increasing reactivity and the impact probability of reactive rubber chain segment under high shear rate is the main reason of shorter scorch time of rubber compounds under high shear rate internal mixing. © 2006 Wiley Periodicals, Inc. JAppl PolymSci 102: 5414–5420, 2006     

Mooney scorch time of epoxidized natural rubber

The scorch property of accelerated sulfur vulcanization of three grades of expoxidized natural rubber (viz. ENR 10, ENR 25, and ENR 50) was studied by using Mooney Shearing Disk Viscometer in the temperature range of 100–180°C. Effects of accelerator types, concentration of accelerator, and carbon black on ENR 10 were also determined. Results obtained indicate a similar scorch behavior as that reported earlier for SMR L. However, some differences in the magnitude of scorch times in the temperature and concentration studies are observed between ENR and SMR L. These differences are attributed to the activation of a double bond by the adjacent epoxide group in ENR, the effect being more significant for a higher degree of epoxidation of natural rubber. In the case of ENR 50, differential scanning calorimetry measurement suggests that additional crosslink occurs via a ring-opening reaction at about 155°C. Based on first-order reaction kinetics, the apparent activation energy of vulcanization for the rubbers studied is estimated and discussed.     

Morphology and rheological properties of nanocomposites based on nitrile rubber and organophilic layered silicates

Organo‐montmorillonite/nitrile rubber (NBR) nanocomposites were prepared by a melt intercalation process. The characteristics of NBR nanocomposites were determined by an oscillating disk rheometer and transmission electron microscopy. The cure characteristics were investigated according to the change in clay content and clay types. This study confirmed that organo‐montmorillonite/NBR nanocomposites have various cure characteristics, namely minimum torque, maximum torque, scorch time and curing time, according to the change in clay content and clay types. In particular, as the chain length of the modifier used for the treatment of Na⁺‐MMT following vulcanization increases, scorch time and optimum curing time are reduced. This is because, as the chain length of the modifier increases, organo‐MMT is distributed more equally during the formation of the nanocomposites. As swelling increases, the chain length of the clay modifier expands and then constitutes a better barrier. Copyright © 2003 Society of Chemical Industry     

不同硫化体系对环保型硬丁腈橡胶性能的影响

以松香酸皂与油酸皂组成的复合乳化体系制备的中试产品丁腈橡胶(NBR)为基胶,分别用硫黄体系和过氧化物体系进行硫化,研究了NBR混炼胶的硫化特性和硫化胶的物理机械性能、耐老化性能、耐油及耐寒性能,并与传统产品NBR 3604进行了比较。结果表明,采用硫黄体系时,NBR混炼胶的硫化程度较浅,硫化速率较慢;采用过氧化物体系时,NBR混炼胶的硫化程度较深,硫化速率较快,NBR胶料宜采用过氧化物硫化体系进行硫化;2种硫化体系下制得NBR硫化胶的物理机械性能与NBR3604硫化胶相差不大,过氧化物硫化体系制得NBR硫化胶的耐老化性能较好;与NBR 3604硫化胶相比,2种硫化体系下制得NBR硫化胶的耐寒性稍好,耐油性稍差。     

贮氢合金催化丁腈橡胶加氢动力学及加氢机理

详细研究了空气气氛下、30～60℃、 THF溶液中贮氢合金催化丁腈橡胶双键加氢的宏观动力学.通过一系列不同反应温度下的实验结果获得了贮氢合金催化丁腈橡胶加氢反应的表观活化能(48.74 kJ•mol^-1),较低的表观活化能表明在贮氢合金催化丁腈橡胶溶液加氢反应中,反应物较易活化且反应具有较低的温度敏感性.利用IR和¹HNMR研究了贮氢合金催化丁腈橡胶双键加氢的选择性,结果表明1,4-BD单元较1,2-BD单元优先加氢,同时给出了trans-1,4-BD和1,2-BD加氢的动力学研究结果.根据动力学及其他研究结果提出了可能的反应机理,该机理较好地解释了反应中出现的现象.     

液体低分子聚异戊二烯改性丁腈橡胶发泡材料

借助核磁共振技术研究了中丙烯腈含量（丙烯腈含量约33%）的4个牌号丁腈橡胶（NBR）的微观结构对NBR硫化速度的影响,以此探索提高NBR硫化速度的方法。结果表明,在NBR分子链中存在着三种微观结构,即顺式1,4-、反式1,4-和乙烯基结构,其中乙烯基结构的含量与NBR的硫化速度有关联的规律性,乙烯基结构含量高则NBR硫化速度快。低分子液体聚异戊二烯（LLPI）作为NBR的改性剂提高了NBR的硫化速度,当添加5份LLPI时,正硫化时间比未添加缩短了约2.5min;LLPI也改善了NBR的加工性能,降低了胶料的门尼黏度;还提升了发泡材料的力学性能,添加5份LLPI的发泡材料拉伸强度增大了14.2%,拉断伸长率减小了27.1%,并且可以与NBR形成交联网络并提高交联结构紧密性,降低胶料的熔体强度,使发泡材料的泡孔生长良好。     

玻璃微珠和炭黑对EPDM胶料硫化特性的影响

考察了玻璃微珠/碳黑用量比对三元乙丙橡胶（EPDM）硫化特性的影响。结果表明,玻璃微珠/炭黑用量比增大时,EPDM胶料的焦烧时间略有延长,最小扭矩和最大扭矩均呈逐步减小的趋势。180 ℃时硫化胶的力学性能优于200 ℃时硫化胶。添加玻璃微珠后,胶料在180 ℃下的正硫化时间缩短近2倍,但200℃下的正硫化时间几乎没有受到任何明显的影响。玻璃微珠会明显减小胶料的硫化温度系数,即添加玻璃微珠后硫化温度对EPDM胶料硫化速度的影响程度将有所减小。