Vulcanization of butyl rubber by p-quinone dioxime dibenzoate

The maximum crosslink density for the dioxime-butyl vulcanizate was obtained at equimolar quantity of the dioxime and red lead. The formation of each quinoid crosslink required about 1.25 molecule of p-quinone dioxime dibenzoate. The vulcanizates consisted mainly of the anil-type crosslink. It was estimated that about 20% of the combined dinitro compounds was wasted in the form of the pendent groups. The vulcanization mechanisms are also discussed.     

环氧型丙烯酸酯橡胶的硫化

通过硫化曲线评定,选用苯甲酸铵作硫化剂环氧丙烯酸酯橡胶低温胶进行硫化。结果表明,共聚单体中甲基丙烯酸缩水甘油酯用量为２％－３％,苯甲酸铵用量为１．５份时,经胶的力学性能最好。二段硫化对硫胶的力学性能几乎无影响。     

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。     

4-氨基脲嘧啶与溴化丁基橡胶反应制备热可逆交联丁基橡胶

在相转移催化剂作用下,用4-氨基脲嘧啶与溴化丁基橡胶(BBR)反应制备了热可逆交联丁基橡胶(IIR),考察了取代反应的影响因素,并研究了含有4-氨基脲嘧啶基团的IIR的结构与拉伸性能.结果表明,4-氨基脲嘧啶取代了BBR中的溴原子,且伯溴代烯丙基结构中的溴原子被完全取代,仲溴代烯丙基结构中的溴原子大部分被取代;IIR上的4-氨基脲嘧啶基团可通过氢键自组装形成热可逆网络结构;在4-氨基脲嘧啶用量为0.010 mol、相转移催化剂四丁基溴化胺/4-氨基脲嘧啶(摩尔比)为1:1、氢氧化钾水溶液/甲苯溶液(体积比)为50:80、反应温度为80 ℃、反应时间为4 h的条件下,4-氨基脲嘧啶与BBR反应后溴原子取代率最大值可达到77%;含有4-氨基脲嘧啶基团的IIR的拉伸强度较BBR增大了2倍,具有热塑性弹性体特征.     

溶液法丁基橡胶的溴化率及溴化丁基橡胶的力学性能

将溶液法丁基橡胶胶液直接溴化制备溴化丁基橡胶（BIIR）,考察了共溶剂、氧化剂、异丁烯残留量、体系水含量和脱酸剂等因素对BIIR溴含量、不饱和度和门尼黏度的影响,并对BIIR硫化胶的力学性能进行了对比评价。结果表明,制备高溴含量BIIR的最佳条件为:共溶剂CH2Cl2体积分数30%,[Na Cl O]/[Br2]3,异丁烯残留质量浓度小于0.05 g/L,体系含水质量分数0.25%~0.50%,脱酸剂环氧大豆油质量分数3.0%;在此条件下制备的BIIR含溴质量分数为（2.20±0.20）%,不饱和度为1.5%,门尼黏度为32±3;与国外同类产品相比,含溴质量分数为2.21%时的BIIR硫化胶的拉伸强度、扯断伸长率和邵尔A硬度较高,其他性能相当。     

羧基丁腈橡胶的硫化性能

用无硫硫化体系、低硫高促进剂硫化体系、普通硫黄硫化体系、过氧化物硫化体系、金属氧化物硫化体系和硫黄／金属氧化物硫化体系对羧基丁腈橡胶（XNBR）进行了硫化,研究了XNBR的硫化性能、物理机械性能、耐老化性能、压缩永久变形和耐油性能。结果表明,采用普通硫黄硫化体系、硫黄／金属氧化物硫化体系所得到的XNBR硫化胶的综合物理机械性能较好;用无硫硫化体系、低硫高促进剂硫化体系和硫黄／金属氧化物硫化体系所得到的XNBR硫化胶的耐老化性能较好;用硫黄／金属氧化物硫化体系所得到的XNBR硫化胶的耐磨性、压缩永久变形较好;用普通硫黄硫化体系和硫黄／金属氧化物硫化体系所得到的XNBR硫化胶的耐油性能较好。     

Effect of butyl rubber type on properties of polyamide and butyl rubber blends

Polyamide‐12 was blended with butyl rubber, bromobutyl rubber, and chlorobutyl rubber with and without a sulfur curing system. Mechanical properties for dynamically vulcanized blends generally exceed those made with no vulcanization. Chlorobutyl‐containing blends prepared by dynamic vulcanization have higher tensile strength and elongation at break values in comparison to those made from other butyl rubbers. For a variety of polyamide/rubber blends made by dynamic vulcanization, there is very little effect of rubber percentage unsaturation and Mooney viscosity on the mechanical properties of the blends. In chlorobutyl‐containing blends prepared by dynamic vulcanization, the swelling index values attributed to the rubber portion decrease as rubber content decreases, and it is likely that the polyamide phase completely surrounds the rubber particles at compositions exceeding approximately 25% polyamide. Swelling index results can be correlated with elongation at break values for similar blends. The results of differential scanning calorimetry suggest that the polyamide phase is not a neutral component in high shear mixing with butyl rubbers with or without curing agents. Rheological studies indicate strong non‐Newtonian behavior for all blends of polyamide‐12 with butyl rubbers. Scanning electron microscopy on polyamide‐12/butyl rubber blends indicates compatibility for butyl rubbers in the order of chlorobutyl > bromobutyl > butyl rubber. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1423–1435, 2004     

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。     

Vulcanization of carboxylated nitrile rubber (XNBR) by zinc peroxide

The vulcanization of carboxylated nitrile rubber (XNBR) with zinc peroxide, which produces ionic crosslinks, has been studied in relation to vulcanization time. Vulcanized compounds present two transitions, corresponding to the glass transition of the polymer at low temperatures and the ionic transition resulting from the formation of ionic aggregates. Both transitions are displaced to higher temperatures with increasing crosslink density. The ionic associations which give rise to high values of mechanical properties disappear on exposure of the vulcanized compounds to saturated ammonia vapour. This treatment produces a decreased crosslink density resulting in the disappearance of the ionic transition. When the action of ammonia is terminated by immersion in solvent followed by drying, the original crosslink density is recovered and the ionic transition reappears, although at higher temperatures. However, with increasing crosslink density, the difference between the temperatures at which both transitions take place diminishes. All these factors can be interpreted as reflecting the generation of a new and more compatible arrangement of the newly-appearing ionic clusters. © 1999 Society of Chemical Industry     

丁基橡胶研究进展

综述了丁基橡胶的生产现状及消费情况,并调研了主要丁基橡胶生产商的产品牌号及性能,对丁基橡胶的消费情况进行了预测。找出了我国丁基橡胶产品与国外产品在技术方面存在的差距,并对丁基橡胶的发展前景进行了展望。     

Silica-grafted polyisobutylene and butyl rubber

Summary Silica surfaces have been modified by reaction with ClSi(CH₃)₂CH₂-CH₂-C₆H₄CH₂Cl (I) and the solids were used in conjunction with Et₂AlCl to initiate the surface-graft polymerization of isobutylene. Experimental conditions have been defined to obtain respectable grafting rates, grafting ratios and grafting efficiencies.     

不干性丁基密封胶

丁基密封胶是由丁基橡胶50－100（质量份，下同），湿润剂10－20，碳酸钙100－150，增粘剂聚丁烯50－80等组成，介绍了制备工艺及国产BS－8型丁基密封胶的性能特点，该胶用于汽车车窗的密封，防风，防水、防尘，性能优良，价格低廉，可以取代同类进口产品。     

Vulcanization of polybutadiene rubber with dipentamethylene thiuram tetrasulfide

The cure of polybutadiene rubber (BR) with sulfur donor dipentamethylene thiuram tetrasulfide (DPTT) does not show reversion reaction, in contrast with similar natural rubber compounds. No polysulfure links are formed; whereas a great amount of ? C? C? crosslinks are produced. The addition of tetramethyl thiuram monosulfidic (TMTM) strongly affects the crosslinking process. Mechanical properties of the cured compounds are poor. In DPTT, curing of BR the radical species produced through homolitic cleavage of DPTT molecule seems to have sufficient energy to produce crosslinking, via allylic abstraction, and also initiate the polymerization of double bonds producing areas of high crosslinking density that induce early material failure. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 106: 3481–3487, 2007     

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。     

Vulcanization kinetics of nano-silica filled styrene butadiene rubber

It was shown that the physical filler-polymer and filler–filler interactions, apart from the filler surface chemistry, has a substantial role in controlling the vulcanization kinetics of styrene butadiene rubber filled with nano-silica in a sulfur vulcanization system. Kinetic studies by the oscillating disc rheometer, differential scanning calorimeter, and swelling tests revealed that the vulcanization rate goes through a maximum as loading of silica increases, but conversion in crosslinking continuously decreases as the amount of silica increases. The effect of silica loadings on the vulcanization reactions was linked to the immobilization of rubber chains around particles as well as in a polymer-mediated filler network, which were differentiated by the nonlinear viscoelastic behavior of rubber vulcanizates. By surface modification of nano-silica, the accelerating/decelerating effects of nano-silica on the vulcanization reactions were altered corresponding to the non-linear viscoelastic behavior of the vulcanizates. Therefore, a mechanism was proposed which correlates vulcanization kinetics of rubber to the dynamics of chains influenced by the reinforcing fillers.     

氯化丁基橡胶/聚丙烯酸酯阻尼橡胶的力学性能

采用聚丙烯酸酯(PA)为第二组分,与氯化丁基橡胶（CIIR)制备了CIIR／PA阻尼橡胶,分析了CIIR／PA共混物的结构,讨论了原料组成、交联剂用量和填料种类对其力学性能的影响、结果表明,CIIR／聚(丙烯酸乙酯-甲基丙烯酸丁酯)[P(EA-BMA)]共混物的正硫化时间为10min．CIIR／聚丙烯酸乙酯(PEA)硫化共混物中存在共交联结构;共交联CIIR／PEA共混物形成了双相连续的微观相态结构;当P(EA-BMA)中PBMA链段的质量分数增加到20%时,共交联CIIR／P(EA-BMA)共混物的拉伸强度和100％定伸应力下降,当P(EA-BMA)中PBMA链段的质量分数继续增加,共混物的拉伸强度和100％定伸应力又逐渐上升,当酚醛树脂(PR)用量不大于20份时,随着PR用量的增加,共交联CIIR／PEA共混物的100％定伸应力和邵尔A型硬度增大,拉伸强度和扯断伸长率减小;当PR用量为30份时,共混物的100％定伸应力减小,拉伸强度增大;填料中以炭黑的增强效果最好,玻璃微球增强效果最差。     

利用超临界二氧化碳流体脱硫再生丁基橡胶

研究了硫黄硫化的丁基橡胶在超临界二氧化碳流体辅助下的脱硫降解行为,讨论了脱硫工艺的条件,并通过凝胶渗透色谱、核磁共振、差示扫描量热等对丁基再生胶的结构和性能进行了考察。结果表明,在二氧化碳的超临界状态下丁基橡胶的脱硫降解更加充分。脱硫的最佳工艺条件为: 反应温度180 ℃,反应压力14. 1 MPa,脱硫剂二苯基二硫的用量为橡胶质量的8%; 经过120 min 脱硫反应后丁基再生胶中溶胶的质量分数为98. 5%。在有热降解和脱硫剂参与的脱硫反应的共同影响下,丁基再生胶中溶胶的数均分子量降至原胶的40%左右; 再生胶主链上接枝了部分脱硫剂的苯环; 硫化和脱硫过程中在接枝于主链上的极性基团的影响下,再生胶中溶胶主链双键氢的振动峰几乎消失,但再生胶的玻璃化转变温度并没有明显变化。     

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.