纳米氧化锌对NR/SBR/BR并用胶性能的影响

研究纳米氧化锌对NR/SBR/BR并用胶性能的影响。结果表明 ,纳米氧化锌用量增大 ,NR/SBR/BR并用胶的正硫化时间缩短 ,耐磨性能和耐热氧老化性能提高 ,但拉伸强度和拉断伸长率下降明显 ;1份纳米氧化锌替代 5份普通氧化锌 ,NR/SBR/BR并用胶的拉伸强度、拉断伸长率、耐磨性能和耐热氧老化性能提高。     

纳米氧化锌在SR中的应用

研究纳米氧化锌分别在NR／SBR，NR／BR，SBR，EPDM，CIIR，NBR和CR中的应用，并与普通氧化锌进行对比。纳米氧化锌因具有特殊的界面效应而使反应活性增大，替代普通氧化锌可以减量使用。纳米氧化锌在二烯烃类SR中用作硫化活性剂，减量幅度可达到40％～60％；在CR中用作交联剂，减量幅度可达20％；纳米氧化锌用量超过减量水平时，胶料性能反而下降。     

纳米氧化锌在NR/BR及NR/BR/SBR体系中的应用研究

纳米氧化锌同时具有纳米材料和普通间接法氧化锌的双重特性,比表面积大、反应活性高,减量使用就可达到与正常相近的活化效果。本试验在全钢子午胎配方中进行,选择NR/BR及NR/BR/SBR生胶体系,用纳米氧化锌代替普通间接法氧化锌,以期减少氧化锌用量,进而降低胶料密度。若此举可在更多配方中推广,对成品胎重量及滚动阻力的降低有积极作用。因市售纳米氧化锌价格较间接法     

纳米氧化锌对NR/BR胎面胶性能的影响

试验研究纳米氧化锌对不同并用比NR/BR并用胶性能的影响及其减量替代间接法氧化锌在载重轮胎胎面胶中的应用。结果表明,以纳米氧化锌等量替代间接法氧化锌用于不同并用比NR/BR并用胶中,胶料的t10和t90延长,且随着BR用量的增大,延迟时间进一步延长;硫化胶的300%定伸应力、拉断强度和回弹值增大,二者300%定伸应力和拉断强度的差值随着NR/BR并用比的变化而无明显变化,回弹值的差值随着BR用量的增大而增大;抗撕裂性能和耐疲劳性能下降;以纳米氧化锌减量25%替代间接法氧化锌用于NR/BR(并用比60/40)胎面胶中,可改善胶料的加工安全性,降低生热,提高老化后性能,成品轮胎的耐久性能有所提高。     

活性氧化锌对天然橡胶 顺丁橡胶 丁苯橡胶胶料性能的影响

研究了活性氧化锌与氧化锌不同并用比对NR/BR,NR/SBR和NR/BR/SBR三种并用胶硫化特性和物理性能的影响。结果表明,选择适宜的活性氧化锌与氧化锌的并用比,可以得到性能较好的胶料。     

活性氧化锌对天然橡胶 顺丁橡胶 丁苯橡胶胶料性能的影响

研究了活性氧化锌与氧化锌不同并用比对NR/BR,NR/SBR和NR/BR/SBR三种并用胶硫化特性和物理性能的影响。结果表明,选择适宜的活性氧化锌与氧化锌的并用比,可以得到性能较好的胶料。     

复合氧化锌胶料的性能研究

试验研究复合氧化锌对NR和SBR胶料及斜交轮胎胎侧胶和胎面基部胶性能的影响.结果表明,当氧化锌用量超过2.5份后,采用复合氧化锌的NR或SBR胶料硫化特性、物理性能和耐热老化性能与采用间接法氧化锌的胶料接近;采用复合氧化锌等量替代间接法氧化锌用于斜交轮胎,胎侧胶性能变化不大,胎面基部胶物理性能有所提高,胶料成本降低.     

有机锌在NR/SBR/BR胎面胶中的应用

以氧化锌作对比,对有机锌在天然橡胶(NR)/丁苯橡胶(SBR)/顺丁橡胶(BR)胎面胶中的应用进行试验研究。结果表明,添加有机锌和氧化锌的2种胶料硫化特性接近;添加有机锌的胶料部分物理性能超过添加氧化锌的胶料,耐热氧老化性能明显优于添加氧化锌的胶料。     

纳米氧化锌母炼胶对NR性能的影响

将纳米氧化锌制成纳米氧化锌母炼胶，研究纳米氧化锌母炼胶对NR硫化胶物理性能的影响及纳米氧化锌的减量机理。试验结果表明，与加5份普通氧化锌相比，加2份纳米氧化锌母炼胶，硫化胶的拉伸强度提高，其它物理性能相近。透射电镜分析表明，纳米氧化锌母炼胶在NR胶料中不存在团聚现象，其分散性优于普通氧化锌和纳米氧化锌。在热力学理论分析基础上提出了纳米氧化锌在橡胶硫化过程中的作用机理。为纳米氧化锌减量60％替代普通氧化锌提供了理论依据。     

纳米氧化锌对天然橡胶疲劳性能的影响

研究了纳米氧化锌对天然橡胶（NR）硫化胶疲劳性能的影响。结果表明,纳米氧化锌对NR胶料的硫化起步延迟作用较大,但却能改善NR的热老化性能,当其用量为5份时综合性能最佳。与普通氧化锌相比,纳米氧化锌会使NR的疲劳寿命下降,其原因主要是纳米氧化锌聚集在橡胶中易于形成微观空穴,疲劳应力作用下逐渐导致宏观上的材料破坏;而普通氧化锌的大粒径颗粒较多,不易发生聚集现象,这也导致了添加纳米氧化锌的NR疲劳断裂后其断裂面较平滑,而添加普通氧化锌的断裂面较粗糙。     

新型白炭黑改性橡胶研究

采用2种新型白炭黑替代常用白炭黑来改性天然橡胶（NR）、顺丁橡胶（BR）、丁笨橡胶（SBR）、三元乙丙橡胶（EPDM）、丙烯酸酯橡胶（ACM）和硅橡胶。研究不同用量和不同种类的白炭黑对上述几种橡胶进行改性,通过对硬度、扯断伸长率、拉伸强度、磨耗和耐老化性能的测试,确定白炭黑的最佳用量和最适宜的种类。结果表明：白炭黑填料用量为80份时效果最好,普通白炭黑适合做EPDM的补强剂,碱法白炭黑对NR、SBR和ACM的改性效果更好,而酸法白炭黑改性的橡胶拉伸强度和硬度很小,不适于补强;白炭黑对硅橡胶的改性效果不好,得到的产品硬度很小,无法进行力学性能测试。     

Influence of rubber composition on change of crosslink density of rubber vulcanizates with EV cure system by thermal aging

Variation of the crosslink density of a rubber vulcanizate depending on the rubber composition after the thermal aging was studied with single rubber, biblend, and triblend vulcanizates of natural rubber (NR), butadiene rubber (BR), and styrene‐butadiene rubber (SBR). The efficient vulcanization (EV) system was employed to minimize the influence of free sulfur in the vulcanizate on the change of the crosslink density. Thermal aging was performed at 40, 60, and 80°C for 20 days with 5‐day intervals. The crosslink densities of the vulcanizates after the thermal aging increase. For the single rubber vulcanizates, variation of the crosslink density by the thermal aging has the order: SBR > BR > NR. For the biblend vulcanizates, variations of the crosslink densities of the NR/SBR and SBR/BR blends are larger than that of NR/BR blend. Variation of the crosslink density of the vulcanizate increases by increasing the SBR content in the vulcanizate. Variation of the crosslink density of the rubber vulcanizate depending on the rubber composition was explained by miscibility of the blends, combination reaction of the pendent groups, and mobility of the pendent group. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 75: 1378–1384, 2000     

Compatibility studies on some polymer blend systems by electrical and mechanical techniques

Systematic electrical and mechanical studies were carried out on natural rubber (NR) blended with different types of synthetic rubber such as styrene‐butadiene rubber (SBR), polybutadiene rubber (BR), and ethylene‐propylene‐diene monomer (EPDM) as nonpolar rubbers and nitrile‐butadiene rubber (NBR) and chloroprene rubber (CR) as polar rubbers. The NR/SBR, NR/BR, NR/EPDM, NR/NBR, and NR/CR blends were prepared with different ratios (100/0, 75/25, 50/50, 25/75, and 0/100). The permittivity (ε′) and dielectric loss (ε″) of these blends were measured over a wide range of frequencies (100 Hz–100 kHz) and at room temperature (∼ 27°C). The compatibility results obtained from the dielectric measurements were comparable with those obtained from the calculation of the heat of mixing. These results were confirmed by scanning electron microscopy and showed that NR/SBR and NR/BR blends were compatible while NR/EPDM, NR/NBR, and NR/CR blends were incompatible. To overcome the problem of phase separation (incompatibility) between NR and EPDM, NBR, or CR, a third component such as SBR or poly(vinyl chloride) (PVC) was added as a compatibilizing agent to these blends. The experimental data of dielectric and mechanical measurements showed that the addition of either SBR or PVC could improve the compatibility of such blends to some extent. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 60–71, 2001     

纯化改性乳聚丁苯橡胶的性能研究

用提纯的方法改性乳聚丁苯橡胶(ESBR),对比改性ESBR(TSBR)、ESBR和溶聚丁苯橡胶(SSBR)的加工工艺和物理性能,并考察3种丁苯橡胶(SBR)与天然橡胶(NR)和顺丁橡胶(BR)并用制备胎面胶的性能。结果表明:TSBR的炭黑分散性、硫化特性和物理性能较ESBR好,生热降低;弹性优于SSBR。TSBR可用于高性能轮胎胎面胶。     

Quantitative characterization of interfaces in rubber–rubber blends by means of modulated‐temperature DSC

Rubber–rubber blends are used widely in industry, for example, in tire manufacture. It is often difficult to characterize interfaces in such rubber–rubber blends quantitatively because of the similarity in the chemical structure of the component rubbers. Here, a new method was suggested for the measurement of the weight fraction of the interface in rubber–rubber blends using modulated‐temperature differential scanning calorimetry (M‐TDSC). Quantitative analysis using the differential of the heat capacity, dCp/dT, versus the temperature signal from M‐TDSC allows the weight fraction of the interface to be calculated. As examples, polybutadiene rubber (BR)–natural rubber (NR), BR–styrene‐co‐butadiene rubber (SBR), SBR–NR, and nitrile rubber (NBR)–NR blend systems were analyzed. The interfacial content in these blends was obtained. SBR is partially miscible with BR. The cis‐structure content in BR has an obvious effect on the extent of mixing in the SBR–BR blends. With increasing styrene content in the SBR in the SBR–BR blends, the interface content decreases. NR is partially miscible with both BR and SBR. The NBR used in this research is essentially immiscible with NR. The maximum amount of interface was found to be at the 50:50 blend composition in BR–NR, SBR–BR, and SBR–NR systems. Quantitative analysis of interfaces in these blend systems is reported for the first time. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 1791–1798, 2000     

不同发泡剂及工艺条件对BR／SBR／NR发泡材料相结构及尺寸稳定性的影响

分别采用一段和两段模压法制备了以顺丁橡胶（BR）／丁苯橡胶（SBR）／天然橡胶（NR）为基体的橡胶发泡材料,研究了三种化学发泡剂N,N＇-二甲基戊次甲基四胺（H）、4,4＇-氧代双（苯磺酰肼）（OBSH）以及H／OBSH（质量比1：1）复配对发泡及硫化特性的影-向,以及3种发泡剂和2种成型工艺对收缩率及相结构的影响。结果表明,发泡剂H对硫化性能影响最大,含发泡剂H的混炼胶在分解过程中释放的热量最多;加入3种发泡剂都具有一种较大的泡孔镶嵌在较小的泡孔丛中的泡孔形态;密度和线收缩率均随着时间的增加而增加,经H／OBSH复配的发泡剂更适合该体系成型,材料线收缩率均比单独使用H和OBSH小,两段模压法可以有效地提高发泡材料的尺寸稳定性,收缩率降低至3．88％,同时发泡剂使用率最多可提高31．67％。     

Effect of nano zinc oxide on the cure characteristics and mechanical properties of the silica‐filled natural rubber/butadiene rubber compounds

With the increasing interest in environmental and health issues, legal restrictions, such as European Union (EU) End of Life Vehicle Directives, were strengthened. This led us to incorporate nano zinc oxide (nano‐ZnO), with particle sizes of 30–40 nm and specific surface areas of 25.0–50.0 m²/g, instead of conventional ZnO into natural rubber (NR)/butadiene rubber (BR) compounds to decrease the content of zinc in the formulation. In the unfilled system, only a 20 wt % nano‐ZnO content, compared to conventional zinc oxide content, showed the cure characteristics and mechanical properties of the same level. This was because the increase in the specific surface area of the nano‐ZnO led to an increase in the degree of crosslinking. The effect of nano‐ZnO on the cure characteristics and mechanical properties was more pronounced in the silica‐filled system than in the unfilled system. This was mainly because of the dispersing agent used in the silica‐filled system, which also improved the dispersion of nano‐ZnO. The silica‐filled NR/BR compounds containing 0.3–3.0 phr of nano‐ZnO showed improved curing characteristics and mechanical properties, such as optimum cure time, 100 and 300% modulus, tensile strength, and tear strength compared to the compound with 5 phr of conventional ZnO. The optimum amounts of nano‐ZnO and stearic acid were only 1.0 and 0.1 phr, respectively. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Silica‐modified SBR/BR blends

The purpose of this article is that the silica‐modified SBR/BR blend replaces natural rubber (NR) in some application fields. The styrene‐butadiene rubber (SBR) and cis‐butadiene rubber (BR) blend was modified, in which silica filler was treated with the r‐Aminopropyltriethoxysilane (KH‐550) as a coupling agent, to improve mechanical and thermal properties, and compatibilities. The optimum formula and cure condition were determined by testing the properties of SBR/BR blend. The properties of NR and the silica‐modified SBR/BR blend were compared. The results show that the optimum formulawas 80/20 SBR/BR, 2.5 phr dicumyl peroxide (DCP), 45 phr silica and 2.5 mL KH‐550. The best cure condition was at 150°C for 25 min under 10 MPa. The mechanical and thermal properties of SBR/BR blend were obviously modified, in which the silica filler treated with KH‐550. The compatibility of SBR/BR blend with DCP was better than those with benzoyl peroxide (BPO) and DCP/BPO. The crosslinking bonds between modified silica and rubbers were proved by Fourier transform infrared analysis, and the compatibility of SBR and BR was proved by polarized light microscopy (PLM) analysis. The silica‐modified SBR/BR blend can substitute for NR in the specific application fields. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.     

环氧树脂增强天然橡胶/顺丁橡胶并用胶的性能

采用低相对分子质量的液体环氧树脂(EP)与固化剂混合作为增强体的前驱体,比较了其填充天然橡胶(NR)、顺丁橡胶(BR)及两者并用胶的物理机械性能,考察了EP用量对并用胶及炭黑增强并用胶物理机械性能的影响,并通过扫描电子显微镜表征了填充后的NR、BR及并用胶的微观相态结构。结果表明,EP的加入均可提高NR、BR、NR/BR并用胶的物理机械性能,其中并用胶的拉伸强度提高幅度最大;当EP用量约为24份时,NR/BR并用胶的综合性能最佳;EP可以提高炭黑增强NR/BR并用胶的物理机械性能,但提高幅度不大;EP在NR/BR并用胶中呈现规整的圆球形状,直径为1.0～2.5μm。     

有机蒙脱土对天然橡胶/丁苯橡胶的补强及增容作用

采用机械混炼法制备了天然橡胶(NR)/丁苯橡胶(SBR)/有机蒙脱土(OMMT)纳米复合材料,采用TEM和XRD对复合材料的亚微观结构进行了表征,并对复合材料的表观交联密度、静态力学性能、动态力学性能和硫化热效应进行了研究。结果表明,复合材料为剥离型纳米复合材料;OMMT能够明显提高纳米复合材料的交联密度和静态力学性能;OMMT导致NR/SBR共混胶动态损耗因子降低,并且能够促使NR和SBR玻璃化转变温度更为接近,起到了增容作用;OMMT实现了NR和SBR两相的同步硫化。