核磁共振法纵向弛豫时间表征胶料中生胶并用比及白炭黑用量的研究

研究用核磁共振(NMR)法纵向弛豫时间(t_1)表征胶料中生胶并用比及白炭黑用量。对不同生胶、白炭黑或炭黑填充的硫化胶和未硫化胶的t_1测试和分析得出:不同生胶具有不同的t_1;同种生胶,测试温度越高,t_1越长;硫化胶的t_1与生胶并用比及白炭黑用量有极高的相关性。NMR法测试胶料t_1可作为快速定量分析胶料生胶并用比及白炭黑用量的新方法。     

填充体系对橡胶悬置元件性能的影响

研究填料种类、用量及并用比对橡胶悬置元件性能的影响。随着炭黑粒径的增大,胶料的门尼粘度和交联密度减小,硫化胶的耐老化性能提高,动静刚度比减小;随着炭黑N550用量的增大,硫化胶的硬度、定伸应力和撕裂强度提高,动静刚度比增大;随着白炭黑用量的增大,炭黑N774与白炭黑并用填充硫化胶的拉伸强度无明显变化,动静刚度比显著增大;在相同硬度下,纯白炭黑填充硫化胶的动静刚度比小于炭黑N774与白炭黑并用填充硫化胶。     

炭黑/白炭黑并用对胎侧胶性能的影响

研究炭黑/白炭黑并用对胎侧胶性能的影响。结果表明：混炼温度影响炭黑/白炭黑并用填充胶料的挤出性能和外观;炭黑/白炭黑并用填充胶料的门尼焦烧时间和t90与炭黑填充胶料相比均明显缩短,并随着白炭黑用量的增大呈延长趋势;随着炭黑/白炭黑并用体系中白炭黑用量的增大,硫化胶的100%和300%定伸应力减小,拉伸强度和拉断伸长率增大,耐臭氧老化性能明显改善,压缩疲劳温升和滞后损失减小,Payne效应呈现先减弱后增强的非线性变化趋势。     

多相炭黑G10填充半钢轮胎胎面胶性能研究

研究偶联剂Si69用量对多相炭黑G10填充半钢轮胎胎面胶性能的影响，并与炭黑及炭黑/白炭黑并用填充胎面胶性能进行对比。结果表明：与炭黑填充胶料相比，炭黑/白炭黑并用填充胶料的门尼粘度较大，t90延长，t10缩短；与炭黑/白炭黑并用填充胶料相比，多相炭黑G10填充胶料的门尼粘度明显减小，t90缩短，混炼胶的Payne效应明显减弱，硫化胶的拉伸强度增大，阿克隆磨耗量和DIN磨耗量减小，压缩生热明显降低，混炼胶中炭黑分散性明显改善；随着多相炭黑G10填充胶料中偶联剂Si69用量的增大，胶料硫化特性和物理性能变化不大，损耗因子减小，其中偶联剂Si69用量为白炭黑用量8%的胶料生热较低，多相炭黑G10分散效果较好。     

充环烷油溶聚丁苯橡胶的实用配合研究

研究补强体系、生胶并用和硫化体系对充环烷油的溶聚丁苯橡胶(SSBR)胶料性能的影响。结果表明:对纯炭黑补强体系,炭黑用量为75份的胶料的综合性能较好,两种炭黑并用体系的胶料的综合性能提高,但耐磨性能稍差,对炭黑/白炭黑并用补强体系,白炭黑用量为20份的胶料的综合性能优异,继续增大白炭黑用量,填料分散性和胶料性能下降;SSBR并用20份顺丁橡胶,胶料的压缩生热和滚动阻力降低,耐磨性能提高,耐老化性能优异,其他性能满足使用要求;在硫化体系中硫黄用量对SSBR胶料性能的影响最大,硫黄的适宜用量为1.4～1.6份。     

稻壳源白炭黑/炭黑/天然橡胶复合材料的性能研究

试验研究稻壳源白炭黑/炭黑并用对天然橡胶硫化胶性能的影响。结果表明:当稻壳源白炭黑/炭黑用量比较高时,胶料的M_L较大,t_(10)较短,t_(90)较长,物理性能较差;当稻壳源白炭黑、炭黑用量较为均衡时,硫化胶的物理性能变化不大,动态力学性能较好;稻壳源白炭黑/炭黑用量比对硫化胶耐寒性能的影响不大;当稻壳源白炭黑/炭黑用量比为20/40和25/35时,硫化胶的综合性能较好。     

多功能橡胶助剂STU的制备及其对白炭黑/天然橡胶复合材料硫化特性的影响

合成了一种新型多功能橡胶助剂STU,研究其对白炭黑/天然橡胶(NR)复合材料加工性能和硫化特性的影响。结果表明:STU结构中含有硫脲官能团和硅氧烷官能团;STU在热压条件下能够原位改性白炭黑表面,有效抑制白炭黑在橡胶基体中形成填料网络结构,改善混炼胶的加工性能;随着白炭黑用量的增大,STU/白炭黑/NR胶料的焦烧时间和正硫化时间延长,交联密度下降;白炭黑的最佳用量为30份。     

炭黑/白炭黑复合填料网络在天然橡胶屈挠疲劳过程中的作用分析

通过改变填料体系中炭黑/白炭黑的用量比,制备出具有不同填料网络结构的硫化胶,通过胶料的硫化特性、交联密度、结合胶含量、Payne效应、损耗特性对填料网络结构进行表征并建立填料网络结构模型,最后通过各种性能测试考察了填料网络对橡胶动静态力学性能和屈挠疲劳性能的影响,建立了复合填料网络结构和屈挠疲劳性能的相关性。结果表明,白炭黑-白炭黑相互作用强于炭黑-炭黑相互作用,但白炭黑与橡胶基体的结合作用差;复合填料网络在屈挠疲劳过程中产生的内耗小,白炭黑/炭黑质量比为20/20时,硫化胶的疲劳性能最好。     

炭黑与白炭黑补强溴化丁基橡胶性能对比

采用RPA2000橡胶加工分析仪对炭黑N660和白炭黑1165分别填充的溴化丁基橡胶(BIIR)混炼胶进行了不同温度下的应变扫描分析。结果表明,2种BIIR胶料的门尼粘度值均随填料用量的增大而增大;在相同用量条件下,白炭黑胶料的门尼粘度值高于炭黑胶料;炭黑胶料的应变与温度依赖性均比白炭黑胶料的强,白炭黑在胶料中的分散好于炭黑,且与BIIR橡胶的相互作用较强;相同硫化体系下,白炭黑胶料的焦烧时间(t10)略长,正硫化时间(t90)明显长于炭黑胶料,最低扭矩和最高扭矩均显著高于炭黑胶料,但硫化胶总体力学性能不如炭黑N660填充的硫化胶。     

促进剂M/DM/D并用比及用量对胶料性能的影响

研究了（促进剂Ｍ＋促进剂ＤＭ）／促进剂Ｄ并用比、促进剂Ｍ／ＤＭ并用比及促进剂总用量对胶料硫化特性及硫化胶物理性能的影响。试验结果表明,（促进剂Ｍ＋促进剂ＤＭ）／促进剂Ｄ并用比为１／０６时硫化速度最快,活性最高;随着促进剂Ｄ用量的增大,焦烧速度加快,交联密度提高;并用促进剂ＤＭ的胶料流动性好,增大促进剂ＤＭ的用量能有效地改善胶料的焦烧性能;随着促进剂总用量的增大,焦烧时间缩短,硫化速度提高,交联密度增大。     

Influence of bound polymer on cure characteristics of natural rubber compounds reinforced with different types of carbon blacks

Rubber compounds are reinforced with fillers such as carbon black and silica. The cure characteristics of a filled rubber compound vary with the filler type and content. The influence of the type of carbon black on the cure characteristics of carbon black filled natural rubber compounds is investigated using two types of carbon black (N220 and N550), which are different in primary size and structure. The cure time and cure rate become faster as the carbon black content increases. The crosslink density also increases and reversion resistance is improved with the increase of carbon black content. The cure time and cure rate of the compound filled with N550 are faster than those of the compound filled with N220 at the same level of bound rubber content. In addition, higher crosslink density is also observed in the compound filled with N550 compared to that of the compound filled with N220 at the same level of bound rubber content. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2282–2289, 2005     

不同白炭黑填充充油溶聚丁苯橡胶的性能

考察了不同白炭黑对填充充油溶聚丁苯橡胶的硫化特性、交联密度、常规力学性能及动态力学性能的影响,分析了白炭黑在胶料中的分散状况,并与炭黑增强胶料进行了对比.结果表明,白炭黑粒径越小、分散性越好,所填充硫化胶的拉伸强度越高,但动态力学性能较差;高分散性白炭黑Z 1165 MP适用于要求高强度、高耐磨的胶料,而粒径相对较大的白炭黑Z 125 Gr适用于要求动态力学性能较好的橡胶制品;白炭黑可达到与炭黑相当的增强效果,与炭黑相比,其在胶料中分散困难,易团聚,因此必须选择合适的混炼工艺才能保证充分发挥其增强作用.     

降低负重轮天然橡胶基复合材料生热的研究状况

概述负重轮天然橡胶(NR)基复合材料的生热原理及表征方法,重点介绍交联结构和填料包括炭黑、硅烷偶联剂改性白炭黑、新型碳材料氧化石墨烯和多壁碳纳米管对复合材料生热影响的研究状况。指出将新型碳材料部分取代炭黑,采用胶乳共沉法制备新型碳材料母胶有利于将新型碳材料均匀分散在NR基复合材料中,在有效提高NR基复合材料强度的同时降低其生热。新型碳材料制备成本高,需要进一步探讨其放量制备的简易方法及分散工艺,以开发能够工业化生产的应用于负重轮的高强度和低生热NR基复合材料。     

Failure properties of thermoplastic elastomers from polyethylene/nitrile rubber blends: Effect of blend ratio,dynamic vulcanization,and filler incorporation

Thermoplastic elastomers from blends of high‐density polyethylene and acrylonitrile butadiene rubber were prepared by a melt‐blending technique. The blends were dynamically vulcanized using sulfur, peroxide, and mixed curing systems. The peroxide concentration was varied to obtain samples of varying degrees of crosslinking. The peroxide system showed better mechanical properties. The crosslink density determination by the equilibrium swelling method revealed that the enhancement in properties can be correlated to the extent of crosslinking. It is observed that the effect of dynamic vulcanization on the property improvement is much more pronounced in rubber‐rich blends. To study the effect of filler incorporation on mechanical properties, fillers such as carbon black, silica, silane‐treated silica, and cork‐filled samples were prepared. All filled systems, except cork filled, exhibited superior mechanical properties. Scanning electron micrographs of selected fractured surfaces were analyzed to study the failure mechanism of the different compositions. Various theoretical models were applied to correlate the observed mechanical behavior with that of theoretically predicted values. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2912–2929, 2006     

Effect of carbon black and thermal aging on the conduction mechanism of natural and styrene butadiene rubbers

Two types of carbon black namely fast extrusion furnace black (FEF) and high abrasion furnace black (HAF) were incorporated with a concentration of 50 phr into styrene butadiene rubber (SBR) and natural rubber (NR). The effect of the time of aging and temperature on the electrical conductivity was studied. It was found that a thermal aging at 95°C leads to the appearance of minimum in conductivity (σ) in both FEF/NR and HAF/NR. This was explained by a competition between two factors: degradation and increase of crosslinking density in the rubber matrix. In case of FEF/SBR and HAF/SBR it seems that these factors have comparable effects on the conductivity after 10 days of aging. From the current-voltage (I-V) characteristics the carrier concentration, trap density, and the drift mobility were calculated. The minimum found in the temperature dependence of σ for FEF/NR is discussed and found to be controlled by the relative dimension of carbon and rubber aggregates.     

辐射预硫化炭黑/白炭黑天然橡胶胶料性能对比研究

对炭黑和白炭黑分别填充的天然橡胶(NR)胶料进行电子辐射预硫化,研究辐射预硫化对胶料的结合胶含量、门尼粘度和硫化特性及硫化胶的物理性能和动态性能的影响。结果表明,辐射预硫化能提高胶料的结合胶含量、门尼粘度和硫化速度,对两种硫化胶的应力应变、生热和磨耗等性能产生不同的影响,并能显著抑制填料在橡胶基体内网络结构的形成,降低胶料的滞后损失。     

Effects of crosslinking reaction and extension strain on the electrical properties of silicone rubber/carbon nanofiller composites

Stretchable conductive silicone rubber (SR) composites are important in wearable electronic devices and the crosslinking of SR composites is necessary for their applications. But the effect of the crosslinking reaction on the electrical conductivity of SR composites is rarely reported. In this article, the effect of crosslinking reaction on the electrical conductivity of SR composites filled with conductive carbon black, carbon nanotubes, and graphene are studied. The crosslink density of SR composites increases with increasing curing time, but the electrical conductivity decreases sharply at the early stage of crosslinking, especially for SR/conductive carbon black composite, which is ascribed to the reaggregation of conductive nanofillers in SR during the crosslinking process. The elastic modulus of the three SR composites gradually increases while the elongation at break decreases with increasing curing time, and the SR/carbon black composite shows ultra-high elongation at break (1578%). In addition, SR/graphene composite is more sensitive to the extension strain than SR/carbon black and SR/carbon nanotubes composites, and its gauge factor is 414 at the strain ranges of 3–25%. This research work brings a new method to optimize the crosslinking structure of conductive SR composites.     

Grafting and crosslinking reaction of carboxyl-terminated liquid rubber with silica nanoparticles and carbon black in the presence of Sc(OTf)3

The grafting of carboxyl-terminated liquid rubbers, specifically polybutadiene (BR-COOH) and nitrile rubber (NBR-COOH), was investigated in the presence of scandium trifluoromethanesulfonate (Sc(OTf)₃) as a catalyst, on silica nanoparticles and on carbon black surfaces. In the absence of the catalyst, the grafting of the liquid rubbers onto silica nanoparticles and carbon black minimally proceeded. In contrast, terminal-carboxyl groups of the liquid rubbers readily reacted with amino groups on silica and phenolic hydroxyl groups on carbon black in the presence of Sc(OTf)₃ to give BR-grafted and NBR-grafted silica and carbon black. After the grafting reaction, Sc(OTf)₃ was easily recovered and the recovered Sc(OTf)₃ could be reused in the grafting of the liquid rubbers onto silica and carbon black. In addition, when an excess of silica nanoparticle and carbon black was reacted in the absence of solvent, the crosslinking reactions of the liquid rubbers by silica nanoparticles and carbon black proceeded in the presence of Sc(OTf)₃.     

Effect of particulate fillers on short jute fiber-reinforced natural rubber composites

The effect of carbon black on the processing characteristics and physical properties of jute fiber-reinforced composites and the role of silica and carbon black in promoting the adhesion between jute fiber and natural rubber have been studied. It was found that presence of silica is not essential to develop adhesion between fiber and rubber in the presence of carbon black. However, silica and carbon black can improve adhesion by minimizing the resin formation and controlling it to a low molecular weight species. Processing properties like green strength and mill shrinkage are improved by the addition of fiber. Carbon black does not affect mill shrinkage, but improves the green strength. Breakage of jute fiber during mixing is severe, but the extent of breakage is not affected by the presence of carbon black. The minimum loading of fiber to achieve reinforcement is reduced in the presence of carbon black. It was also found that the presence of clay in jute fiber rubber composites impairs the properties. Scanning electron microscopy (SEM) has been used to assess the failure criteria.     

Effect of high-abrasion furnace carbon black on the course of thiuram-accelerated sulfur vulcanization

The effect of high-abrasion furnace (HAF) carbon black on the course of the tetra-methylthiuram disulfide-accelerated sulfur vulcanization of natural rubber has been investigated at temperatures from 100°C to 140°C. Continuous measurements in a Vuremo curemeter were used to estimate the extent of crosslinking, which was plotted against cure time. Results now available show (1) HAF carbon black does not alter the mechanism of the thiuram-accelerated sulfur cure; it also has no qualitative effect on the kinetics of the vulcanization reactions involved. (2) Quantitatively speaking, essential differences take place. The rate constants of vulcanization rise considerably when HAF carbon black is used; there is a dependence on the HAF carbon black content of the rubber compound. Yet the activation energies of vulcanizations are practically the same as in carbon black-free mixture, amounting to about 31 kcal/mole. (3) Measurements of the course of vulcanizations prove the reinforcing effect of HAF carbon black.