NR／BR／EPDM共混胎侧胶中EPDM的结构：分子结构和炭黑分布对性能的影响

自EPDM问世以来,它在轮胎中的应用一直是一个难题。早在1960年,就认为这种橡胶可做为整体轮胎中SBR橡胶的耐臭氧的替代品。的确,曾用EPDM橡胶制成过完整的轮胎。但因其性能低劣,主要是耐磨耗、抗裂口增长和滚动阻力等性能不足,因而使EPDM从来没有在轮胎中得到应用。除此之外,缺乏自粘性也是轮胎生产中的一个主要问题,尽管通过选择合适的聚合物变量可以在很大程度上克服这一问题。     

新型XMT炭黑在全钢载重汽车子午线轮胎胎侧胶中的应用

研究新型XMT炭黑在全钢载重汽车子午线轮胎胎侧胶中的应用。结果表明,在全钢载重汽车子午线轮胎胎侧胶中采用XMT炭黑部分替代炭黑N375,胶料的加工安全性能、硫化特性、挤出工艺性能和物理性能可以达到要求,具有综合成本优势。     

不同厂家炭黑对胎侧胶性能的影响

研究对比了相同牌号、不同厂家的炭黑对胎侧胶性能的影响.结果表明,不同纯度的炭黑,随着筛余物、加热减量的减少,胶料的分散性和拉断伸长率等性能有不同程度提高,胎侧胶回弹性及成品胎的胎侧屈挠性能得到提升.     

炭黑对轮胎胎侧胶黑度的影响

研究炭黑品种和用量对轮胎胎侧胶黑度的影响。结果表明:在胎侧胶的常用炭黑中,当炭黑用量相同时,黑度大小顺序依次为:N375,N326,N330,N660;在全天然橡胶(NR)或NR/顺丁橡胶(50/50)配方中,当炭黑用量为46份时,胎侧胶的黑度达到最大值;通过调整生产配方,在保证性能的同时可以提高胎侧胶的黑度。     

提高全钢工程机械子午线轮胎胎侧胶和胎圈外护胶耐臭氧老化性能的研究

为提高全钢工程机械子午线轮胎胎侧胶和胎圈外护胶的耐臭氧老化性能,对其新防护体系试验配方进行了研究。结果表明,胎侧胶和胎圈外护胶防护体系均采用防老剂6PPD／TMQ／MDPPD／B型微晶蜡并用,有利于提高成品轮胎的耐臭氧老化性能,改善轮胎的耐久性能。     

钕系顺丁橡胶在全钢巨型工程机械子午线轮胎胎侧胶中的应用

试验研究两种钕系顺丁橡胶(NdBR)CB22和CB24在全钢巨型工程机械子午线轮胎胎侧胶中的应用。结果表明:与镍系顺丁橡胶相比,NdBR胶料具有较优的硫化平坦性,硫化胶具有较好的综合物理性能和耐屈挠性能及较低的压缩生热;CB22与CB24相比,CB22硫化胶具有较好的物理性能和较低的压缩生热,而CB24硫化胶具有较好的耐屈挠性能。     

活性纳米碳酸钙在全钢子午线轮胎胎侧胶中的应用

试验研究活性纳米碳酸钙在全钢子午线轮胎胎侧胶中的应用。结果表明,在全钢子午线轮胎胎侧胶中添加10份活性纳米碳酸钙,胶料的硫化速度加快,硫化胶的硬度、拉断伸长率略有增大,拉伸强度、定伸应力相当,胶料生产成本降低,具有一定的经济效益。     

改性氧化锌在全钢载重子午线轮胎胎侧胶中的应用

研究改性氧化锌在全钢载重子午线轮胎胎侧胶中的应用。结果表明:在胎侧胶中采用改性氧化锌等量替代间接法氧化锌,胶料的加工性能和物理性能基本保持不变,成品轮胎的耐久和高速性能达到国家标准要求;胶料成本降低,环保效益提高。     

全钢载重子午线轮胎胎侧胶硫化体系的研究

研究硫化体系中硫黄和促进剂用量对全钢载重子午线轮胎胎侧胶性能的影响。结果表明：在胎侧胶配方中减小硫黄用量并增大促进剂TBBS用量,胶料的硫化特性和老化前物理性能变化不大;当硫黄/促进剂TBBS用量比为1.5/2.3时,胶料的物理性能、耐老化性能和动态力学性能最佳。     

Reinforcement Mechanism of Carbon Black (CB) in Natural Rubber Vulcanizates: Relationship Between CB Aggregate and Network Structure and Viscoelastic Properties

Carbon black (CB) aggregates in CB-filled natural rubber (NR) vulcanizate were joined together and formed CB aggregates in the CB region less than 20?phr. It was found that the viscoelastic behavior was related to the hydrodynamic interaction between CB aggregate and NR matrix. In the CB loading region more than 40?phr, CB aggregates formed CB network structure in it. Using the parallel mechanical model of the two phases of a rubber matrix and an immobilized CB/NR interfacial layer excluding a CB phase, it was possible to quantitatively explain the relationship between the viscoelastic behavior of CB network structure.     

Studying the pulverization mechanisms of low-cross-link-density natural rubber with and without carbon black

The effects of the temperature in the different heating zones and the rotating speed of the screw in the Solid State Shear Extrusion (SSSE) process were studied to obtain a better understanding of the pulverization mechanisms of the low-cross-link-density natural rubber. Results showed that providing a range of both temperature and normal stress was required to pulverize cross-linked natural rubber, but shear stress plays the most important role to produce fine particles. Two rubber samples were provided with the same composition, but one with carbon black (CB) and the other one without, and were pulverized at the same process conditions to show the effect of the material mechanical properties on the produced particles' average size. The average produced particle size of the sample without CB was considerably smaller than the one with, and they were electrostatically charged. Based on this result, under combination of the shear and normal stresses, adding hard particles (in this case CB) to the cross-linked rubber increases its dissipation energy, therefore less energy is restored for the material fracture.     

PPC/SBR共混物的研究 Ⅱ.混炼工艺对共混物性能的影响

研究了混炼工艺对聚亚丙基碳酸酯（ＰＰＣ）／ＳＢＲ共混物性能的影响。结果表明,采用混炼工艺Ａ（ＳＢＲ＋ＰＰＣ→配合剂→陈化１２ｈ→ＭＡ→返炼→硫化）,可在提高硫化体系活性的基础上消除陈化对共混物拉伸性能的影响;将ＰＰＣ与ＳＢＲ预混后混炼,可提高共混物的定伸应力和硬度,降低扯断永久变形;停放时间延长（２ｈ以内）有利于共混物性能的提高;薄通次数增加对共混物性能无显著影响。     

Effects of Carbon Fillers on Crystallization Properties and Thermal Conductivity of Poly(phenylene sulfide)

Differential scanning calorimetry and polarized optical microscopy methods were used to investigate the crystallization behavior and isothermal crystallization kinetics of poly(phenylene sulfide) (PPS)/carbon nanotube (CNT) and PPS/CNT/carbon fiber (CF) composites. In this article, the influences of CNT and CF on PPS crystallization behavior are explained. The thermal conductivity properties of composites were studied using the laser flash method. The results show that CNT increased crystallization temperature and rate and thermal conductivity greatly improved at 8 wt.% CNT content. In addition, the crystallization and thermal performance of PPS are significantly improved via synergistic effects of CNT and CF in the composites.     

聚乙烯/炭黑导电复合材料PTC特性的研究(Ⅱ)--辐射交联对导电复合材料PTC性能的影响

采用^60Coγ-射线对HDPE／CB导电复合材料进行辐射处理，研究了辐射剂量对于该复合材料室温电导率、PTC性能及稳定性的影响。结果发现，在50-300kGy范围内，随着辐射剂量的增加，复合材料的PTC强度增大，且复合材料的稳定性有所提高，NTC效应有所降低；同时，辐射交联对体系的室温电阻率影响不大。DSC测试表明，当辐射剂量为150kGy时，辐射处理对于HDPE的熔点、结晶度影响不大。     

Electrophoretic deposition of hydroxyapatite nanostructured coatings with controlled porosity

Hydroxyapatite (HA) coatings with controlled porosity were prepared by electrophoretic deposition (EPD) method. Carbon black (CB) particles were used as the sacrificial template (porogen agent). Two component suspensions containing different concentrations of HA and CB particles were prepared in isopropanol. It was found that the finer and positively charged HA nanoparticles are heterocoagulated on the coarser and negatively charged CB particles to form CB–HA composite particles with net positive charge. The deposition rate from the suspensions with WR (C_CB/C_HA ratio) of 0.25 was faster than that of those with WR: 0.5 at initial times of EPD. However the situation was reversed at longer EPD times. It was also found that the amount of porosity in the coatings increases as the CB concentration in the suspension increases (15%, 24%, 31%, 43% for the coatings deposited from the suspensions with 20 g/L HA nanoparticles and 0, 5, 10 and 20 g/L CB particles, respectively).     

硫化氢对氢化丁腈橡胶性能的影响

就硫化氢与丁腈橡胶和氢化丁腈橡胶的不饱和双键,以及与丙烯腈侧基的老化反应的机理作了介绍。研究表明:氢化丁腈橡胶具有优异的耐硫化氢性能,适合用来生产石油钻探领域的相关橡胶制品。     

Effect of Silane Coupling Agent on the Mechanical Properties of Clay Filled Styrene Butadiene Rubber

Abstract

The effect of treatment of coupling agent [Bis (3-triethoxy-silyl-propyl) tetrasulphide] on mechanical properties of composites made from styrene butadiene rubber and clay is reported in this paper. The coupling agent in the form of solution (1.0%) was used for treatment of the filler. The treatment resulted in enhancement of mechanical properties of composites when compared with composites containing untreated clay. The properties under consideration were tensile strength, modulus at 100% and 400%, Young's modulus, hardness, etc. Good reinforcement was observed due to treatment of 1% coupling agent. Tensile strength was improved by 11%, modulus at 400% was found to improve by 237%, elongation at break was improved by 250%, while Young's modulus also was improved by 298% for treated clay composites, respectively, at 0.41 volume fraction when compared with untreated clay composites.     

Electrochemical deposition of Pt nanoparticles on CNTs for fuel cell electrode

In order to increase the performance of fuel cell electrode, carbon nanotubes (CNTs) were used as support instead of conventional carbon black, and the Pt catalyst was synthesized by using electrochemical deposition (ECD) method which has recently been adopted as a synthetic tool of metal nanoparticles. CNTs used in this paper were grown directly on carbon paper by chemical vapor deposition (CVD) of acetylene. Highly dispersed and nano-sized Pt particles were electrochemically deposited on CNTs surface, which would simplify the manufacturing process of membrane-electrode-assembly (MEA). Pt particles on CNTs were investigated by SEM and TEM. The particle size of Pt is less than 2 nm, which is relatively small compared to that of conventional wet impregnated catalyst (2–8 nm). CO chemisorption results show that the amounts of catalytic sites are about three times larger in Pt/CNT prepared by ECD than those in conventional wet-impregnated one. The mass activity of the former catalyst for oxygen reduction is more than three times higher compared to that of the latter one. This paper was presented at the 11th Korea-Japan Symposium on Catatysis held at Seoul, Korea, May 21–24, 2007.     

AM与HEMA共聚制备水凝胶接触镜材料及其溶胀性能

采用丙烯酰胺(AM)与甲基丙烯酸β-羟乙酯(HEMA)进行本体共聚制备水凝胶接触镜材料,研究了水凝胶的溶胀性能及其温度和pH值敏感性。结果表明,引发剂过氧化苯甲酰(BPO)用量为反应单体总质量的0.3%、反应温度80℃,产物溶胀之后为无色透明的玻璃状水凝胶;共聚物水凝胶具有较好的pH值敏感性,水凝胶在酸性溶液中溶胀,在碱性溶液中收缩:含有AM的水凝胶,其pH值敏感性较大:随AM的含量增大,共聚物水凝胶的溶胀速度和饱和含水量增大,随温度升高,水凝胶的饱和含水量下降,共聚物水凝胶中AM的含量对其温度敏感性无显著影响:SEM照片显示,AM与HEMA共聚物存在均匀的纤维状结构,并且共聚物中AM的含量越大,这种纤维状结构越大、越明显。