异戊二烯含量对硫黄硫化丁基橡胶硫化特性的影响

本文主要通过无转子硫化仪研究异戊二烯含量对硫黄促进剂体系硫化丁基橡胶硫化特性及硫化动力学的影响。研究表明,在实验范围内,Ghoreishy动力学方程能较好地描述丁基橡胶硫磺硫化的行为。在相同硫化温度下,随着异戊二烯单元含量的增多,焦烧时间、正硫化时间逐渐缩短,交联密度明显增加,高温抗硫化返原性增强。随着硫黄用量的增多,丁基橡胶硫化胶的交联密度随硫黄用量呈线性增加,高异戊二烯含量的丁基橡胶硫黄硫化效率大幅度提高,反应级数增大,硫化活化能Ea明显降低,但异戊二烯含量从5.1mol.%增加到7mol.%时,硫黄硫化效率并未出现明显增加,Ea基本不变。     

Molecular mobility in ultrasonically treated butyl gum and devulcanized butyl rubber

In an effort to improve our understanding of the structural changes during ultrasonic treatment, proton NMR transverse relaxation was used to study butyl rubber gum before and after ultrasonic treatment, and ultrasonically devulcanized unfilled butyl rubber. The relaxation decay was successfully described using a two-component model. The short component is attributed to entangled and crosslinked networks including the high molecular weight fraction of the sol, and the long component arises mainly from low molecular weight fractions of the sol. All component molecular mobilities and the relative contributions of the components to the echo were investigated. The present results were compared with our previous NMR studies of other devulcanized rubbers.     

丁基橡胶淤浆法生产工艺及经济效益分析

介绍了丁基橡胶淤浆法生产工艺,对聚合釜结构及清洗要求、闪蒸与汽提操作方法、氯甲烷(CH3Cl)的循环精制、丁基橡胶浆料的后处理以及生产工艺中的原辅料及公用工程消耗指标等作了阐述。结合市场分析和工程经济相关原理,讨论了建设1套3万t/a丁基橡胶生产装置的经济效益和抗风险能力。     

Development of butyl rubber nanocomposites in presence and absence of compatibiliser

Abstract

Chlorobutyl rubber nanocomposites containing organically modified nanoclay (CI-C) were prepared by solution mixing. The nanoclay used in this study was Cloisite 20A. The obtained nanocomposites were incorporated in butyl rubber (IIR) with sulphur as a curing agent. Morphology, curing characteristics, mechanical and gas barrier properties of the nanocomposites were analysed. The morphological studies proved the partial exfoliation along with agglomeration of nanoclay platelets in chlorobutyl rubber, and further incorporation of CI-C in IIR matrix enhance the exfoliation of the nanoclay platelets. Curing study demonstrated shorter scorch time, cure time and increase in maximum torque for the nanoclay loaded IIR compound in the presence of chlorobutyl rubber as a compatibiliser compared to pure and IIR-nanoclay compound without compatibilisers. Dynamic mechanical thermal analysis results showed tremendous improvement in storage modulus and decrease in tan?δ value for the one containing a compatibiliser. This particular compound exhibited substantial improvement in mechanical and gas barrier properties.     

Changes in physical properties and molecular structure of butyl rubber during γ-irradiation

Butyl rubber samples have been aged by γ-irradiation at 25°C in air. The change in molecular structure due to chain scission and formation of oxygenated groups also change the $\text{M}\text{?}{}_{\mathrm{n}}$, tensile strength and density of butyl rubber. The rubber predominantly undergoes chain scission upon γ-irradiation up to a dose of 50 Mrad, but there is also substantial chain crosslinking above 50 Mrad. The yield G(x) has been found, which provides an insight into the mechanism of the radiolytic degradation. Hydroperoxide is the major product and unsaturation is incorporated in the polymer back bone. The change in molecular structure due to recombination and chain scission are followed by the formation of a more ordered structure and hence an increase in density.     

Unexpected gel from anhydride-modified polypropylene/butyl rubber blends

Blends of melt-mixed butyl rubber (IIR) and anhydride-modified polypropylene (mPP) were observed to exhibit an insoluble fraction after extraction with boiling xylene. Possible origins of this insoluble fraction were carefully examined and it was unequivocally shown that the insoluble portion corresponds to the mPP gel formed via ionic crosslinking. The ion responsible for the crosslinking of mPP was identified as Al³⁺ (from residue of the aluminum chloride catalyst used in the synthesis of IIR) at a trace level of 200 ppm, which presumably diffused from the IIR phase to the mPP phase during the extraction process. In the case of dynamically vulcanized mPP/IIR blends, the formation of mPP gel from this ionic mechanism was found to be insignificant. This is attributed to the strong tendency of the phenolic curative to form ionic complexes with the Al³⁺ ion in the IIR phase.     

改性丁基橡胶PMIIR的动态力学性能研究

采用氢化钠(NaH)/马来酸酐(MAH)体系和无溶剂的本体方法,在橡胶加工设备中对丁基橡胶(IIR)进行了多官能化改性反应,得到了加工改性丁基橡胶(PMIIR)。通过红外光谱对产物结构进行了分析表征,该反应在丁基橡胶分子链上同时引入了不饱和的碳碳双键和羧基官能团。采用动态机械分析(DMA)和橡胶加工分析(RPA)方法对PMIIR的动态力学性能进行了分析。结果表明,混炼胶在低应变和高应变时储能模量的差值(ΔG′)受改性剂用量的影响不大,而硫化胶的ΔG′随改性剂用量的增加而增加,说明改性剂的用量对硫化体系网络有一定影响,IIR中引入极性基团,橡胶与填料的相互作用增强。硫化胶的动态模量受应变影响较大,随应变增加而大幅降低,损耗因子随应变的增加而增加。     

丁基橡胶市场分析

介绍了丁基橡胶的基本性能,综述了国内外丁基橡胶的生产、供需、消费及价格状况。分析表明,国产丁基橡胶的品种和数量均不能满足国内需求,在产品质量和原材料消耗等方面与国外存在着差距,我国必须大力发展丁基橡胶。     

丁基橡胶及卤化丁基橡胶阻尼材料的研究进展

介绍了丁基橡胶的阻尼性能及应用,阐述了丁基橡胶、氯化丁基橡胶及溴化丁基橡胶阻尼材料的研究进展.指出提高损耗因子和拓宽阻尼温域是丁基橡胶基高性能阻尼材料的研究方向,丁基橡胶与其他橡胶共混、开发合适的硫化体系和填料是提高丁基橡胶基阻尼材料性能的重要手段.     

溶胀法测定丁基橡胶及卤化丁基橡胶的一维溶度参数

采用溶胀法测定了丁基橡胶(IIR)、氯化丁基橡胶(CIIR)和溴化丁基橡胶(BIIR)的一维溶度参数(δ),通过Flory–Rehner方程和交联点之间的平均摩尔质量计算了橡胶与溶剂的相互作用参数χ。结果表明,IIR、CIIR、BIIR的δ值相差不大,分别约为17.0,16.5,17.5 MPa1/2;IIR与烃类非极性溶剂的χ略大于CIIR及BIIR与相应溶剂的χ,环己烷和四氯化碳是这3种橡胶的良溶剂。     

丁基橡胶聚合新型超重力反应器工艺

将新型旋转填充床反应器（RPB）应用于阳离子聚合制备丁基橡胶（IIR）过程。实验初步考察了旋转填充床转子转速（N）和聚合温度（T_p）等工艺参数对聚合产物IIR分子量和分子量分布的影响规律。研究结果表明：在实验条件下,当N=1200 r·min^-1、T_p=-100℃时,采用超重力法新工艺制备的IIR的数均分子量达到2.89×10⁵,分子量分布指数达到1.99。同时,物料停留时间小于1 s (现工艺30~60min),单位设备体积的生产效率提高了2~3个数量级。随着N的增大和T_p的降低,聚合产物IIR的分子量升高,而分子量分布变化不大。     

丁基橡胶生产及市场分析

介绍了国内外丁基橡胶（IIR）的生产现状,总结了IIR的产能、进出口量和表观消费量,并对国内IIR的市场发展趋势进行了分析及预测。此外,还对国内IIR行业的发展提出了几点建议。     

丁基橡胶/丙烯酸酯橡胶共混物-钢片复合制件的粘接性能

制备了酚醛树脂硫化的丁基橡胶(IIR)/丙烯酸酯橡胶(ACM)共混物,并研究其与钢片的粘接性能。对剥离强度、断面形貌及表面能等的研究结果表明,引入ACM有效地改善了IIR与钢片的粘接性能,使其剥离强度提高2~3倍;并用ACM后,体系剥离强度的提高是物理黏着和化学黏着共同作用的结果;钢片-橡胶复合制件的破坏形式主要是橡胶部分的破坏及橡胶与胶黏剂之间的破坏。当IIR与ACM质量比为70/30时,试样剥离破坏形式表现为100%的橡胶本体破坏。增大界面作用力、适当降低共混硫化胶本体强度有利于提高体系的粘接性能。     

丁基橡胶IIR—1751用于密封腻子的研制

用国产的丁基橡胶IIR-1751研制了密封腻子。测试结果表明,其主要性能符合实际应用的需求,可作为用进口丁基橡胶生产密封腻子的替代品。     

丁基橡胶合成研究进展与市场展望

简述了丁基橡胶(IIR)的合成技术进展,丁基橡胶生产技术有淤浆及溶液聚合两种工艺,近年来的合成技术主要围绕两种工艺的改进进行,如使用茂金属、二卤代单烷基铝和铝氧烷混合物等新型催化剂;使含卤单体参与共聚合直接制备卤化IIR等。通过分析橡胶和医用胶塞等的市场前景,提出了在国内开发丁基橡胶的必要性和紧迫性。     

硅橡胶/有机橡胶共混改性的研究进展

综述了近年来硅橡胶与三元乙丙橡胶、氟橡胶、橡胶型乙烯-乙酸乙烯酯、丙烯酸酯、聚氨酯等有机橡胶共混改性的最新研究与应用状况.介绍了硅橡胶/有机橡胶共混改性材料的发展动向.     

丁基橡胶生产技术及市场分析

丁基橡胶具有优良的气密性、水密性以及优良的耐候性和耐化学腐蚀性,是内胎和无内胎轮胎密封内衬不可替代的胶种。本文介绍了国内外丁基橡胶生产技术现状。总结了丁基橡胶的产能、进出口量和表观消费量,并对国内丁基橡胶的市场发展趋势进行了分析及预测。此外,本文还对国内丁基橡胶行业的发展提出了几点建议。     

硅橡胶/有机橡胶共混改性的研究与应用

硅橡胶是一种综合性能优异的橡胶，目前已在许多共混物中应用。本文综述了近几年来硅橡胶／有机橡胶（三元乙丙橡胶、氟橡胶、橡胶型乙烯-乙酸乙烯酯、丙烯酸酯、聚氨酯橡胶）共混改性的最新研究状况与应用。最后介绍了硅橡胶／有机橡胶共混改性材料的发展方向。     

溴化丁基橡胶的热可逆共价交联

利用季铵化反应的热可逆特性,采用含有叔胺官能团的聚合物替代传统交联剂,研究了溴化丁基橡胶(BIIR)的交联反应活性及交联的热可逆性.结果表明,硫化温度和硫化时间对交联BIIR的凝胶含量有显著影响,在160 ℃×30 min的硫化条件下,交联剂呈现出较高的交联活性;不同温度下的转矩测定和190 ℃二次热压的塑性流动证实交联BIIR具备热塑加工性.