影响顺丁橡胶装置运行周期的原因分析

顺丁橡胶作为轮胎制造业、耐寒防震制品的主要原材料,是仅次于丁苯橡胶的世界第二大通用合成橡胶,市场需求非常大,但由于国外相关生产技术封锁,目前国内顺丁橡胶生产技术落后,装置运行周期相对较短,精馏塔、反应釜、换热器、胶液管线等设备的堵、挂、腐蚀现象一直是制约橡胶生产的致命因素。本文针对生产中发现的诸多影响顺丁橡胶运行周期的问题进行深入讨论,提出有针对性的防范和改进措施,确保顺丁橡胶装置能够长周期稳定运行。     

Thermal and scanning electron microscopy/energy‐dispersive spectroscopy analysis of styrene–butadiene rubber–butadiene rubber/silicon dioxide and styrene–butadiene rubber–butadiene rubber/carbon black–silicon dioxide composites

Silica as a reinforcement filler for automotive tires is used to reduce the friction between precured treads and roads. This results in lower fuel consumption and reduced emissions of pollutant gases. In this work, the existing physical interactions between the filler and elastomer were analyzed through the extraction of the sol phase of styrene–butadiene rubber (SBR)–butadiene rubber (BR)/SiO₂ composites. The extraction of the sol phase from samples filled with carbon black was also studied. The activation energy (E_a) was calculated from differential thermogravimetry curves obtained during pyrolysis analysis. For the SBR–BR blend, E_a was 315 kJ/mol. The values obtained for the composites containing 20 and 30 parts of silica per hundred parts of rubber were 231 and 197 kJ/mol, respectively. These results indicated an increasing filler–filler interaction, instead of filler–polymer interactions, with respect to the more charged composite. A microscopic analysis with energy‐dispersive spectroscopy showed silica agglomerates and matched the decreasing E_a values for the SBR–BR/30SiO₂ composite well. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 2273–2279, 2005     

Improvement of the homogeneity of SBR/NBR blends using polyglycidylmethacrylate‐g‐butadiene rubber

Polyglycidylmethacrylate grafted butadiene rubber (PGMA‐g‐BR) was synthesized by a graft solution copolymerization technique. The PGMA content was determined through titration against HBr. The PGMA‐g‐BR was blended with styrene butadiene rubber/butadiene acrylonitrile rubber (SBR/NBR) blends with different blend ratios. The SBR/NBR (50/50) blend was selected to examine the compatibility of such blends. Compatibility was examined using scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and viscosity measurements. The scanning electron micrographs illustrate the change of morphology of the SBR/NBR rubber blend as a result of the incorporation of PGMA‐g‐BR onto that blend. The T_gs of SBR and NBR in the blend get closer upon incorporation of PGMA‐g‐BR 10 phr, which indicates improvement in blend homogeneity. The intrinsic viscosity (η) versus blend ratio graph shows a straight‐line relationship, indicating some degree of compatibility. Thermal stability of the compatibilized and uncompatibilized rubber blend vulcanizates was investigated by determination of the physicomechanical properties before and after accelerated thermal aging. Of all the vulcanizates with different blend ratios under investigation, the SBR/NBR (25/75) compatibilized blend possessed the best thermal stability. However, the SBR/NBR (75/25) compatibilized blend possessed the best swelling performance in brake fluid. The effect of various combinations of inorganic fillers on the physicomechanical properties of that blend, before and after accelerated thermal aging, was studied in the presence and absence of PGMA‐g‐BR. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1559–1567, 2006     

Styrene butadiene rubber/epoxidized natural rubber/carbon filler nanocomposites: microstructural development and cure characterization

Microstructural development of elastomeric nanocomposites based on (50/50 wt%) styrene butadiene rubber (SBR) and epoxidized natural rubber (50 mol% epoxidation, ENR50) as the rubber matrix including two types of carbon fillers, carbon black (CB) and functionalized multiwall carbon nanotube (NH₂-MWCNT), which were prepared through melt mixing, was studied. The results from FTIR analysis show that there is interaction between functional groups on MWCNT surface and the rubber chains. The AFM analysis also indicates good dispersion of filler particles in the rubber phases. FESEM images from cryo-fractured surface of samples have revealed that nanotubes were rarely pulled out of matrix and their diameter increased, resulting from good interaction between MWCNTs and rubber chains. The DMA results confirm good interfacial interaction between them. Furthermore, the reduced difference between the two T_gs of phases (ΔT_g) shows that the incorporation of 3 phr MWCNT into the blend leads to increment in rubber phase compatibility but at higher MWCNT content (5 phr) due to lower Mooney viscosity of SBR phase, MWCNTs tend to remain in this phase. The bound rubber was adopted to characterize the polymer–filler interaction, showing that bound rubber content has an increasing trend with increasing in fillers content. The cure rheometric studies reveal that MWCNTs accelerate the cure process due to the presence of amine groups on the nanotube surface. In addition, the mechanical properties of samples show an increasing trend by increasing nano-filler content.

     

溶聚丁苯橡胶与不同结构顺丁橡胶并用的SiO2/SSBR/BR复合材料性能研究

传统的镍系顺丁橡胶BR9000和四种稀土顺丁橡胶以低并用比（25phr）与SSBR并用时,BR9000与SSBR并用的硫化胶性能与稀土顺丁橡胶并无明显差距,有些性能还要比一些稀土顺丁橡胶更加优良。稀土顺丁橡胶CB24在物理机械性能方面表现出较好的综合性能。具有长链支化结构的稀土顺丁橡胶Nd24EZ具有最高的直角撕裂强度和最低的裂纹扩展速率。具有长链支化结构和高门尼粘度的稀土顺丁橡胶Nd22EZ则具有最佳的滚动阻力和抗湿滑性能。CB24虽然在抗湿滑性能方面表现优良,但其滚动阻力性能在五种顺丁橡胶中是最差的。Nd22EZ与Nd24EZ与白炭黑的相互作用力最强,白炭黑分散最好,表现出最低的佩恩效应。CB24和SKD-NDII则与白炭黑相互作用力较弱,白炭黑分散较差,佩恩效应最强。     

硅橡胶/丁苯橡胶并用胶的制备及表征

针对硅橡胶具有较高的耐热性,但力学性能差;丁苯橡胶(SBR)力学性能较好,但粘性较差;提出了将硅橡胶与SBR共混,制成共混材料;采用偏光显微镜、傅里叶变换红外光谱、差示扫描量热仪以及力学性能、热老化性能测试手段,研究了甲基乙烯基硅橡胶(MVQ)/SBR共混体系的并用比(质量比)、硫化工艺参数以及顺丁橡胶(BR)的加入对力学性能、耐热老化性能和相容性的影响。结果表明:MVQ与SBR最佳配比为30/70,白炭黑为45份;最佳硫化工艺参数为170℃×10 MPa×30 min。MVQ/SBR并用胶的玻璃化温度为-20℃,MVQ和SBR具有较好的相容性。     

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     

固相法改性淀粉／炭黑／丁苯橡胶复合材料的制备与性能研究

采用固相法制备了淀粉接枝马来酸酐（MAH）和丙烯酸丁酯（BA）的共聚物Starch-gMAH／BA（SMB）。采用机械共混法用15phr的改性淀粉（SMB）代替等量的炭黑（CB）,制备了改性淀粉／炭黑／丁苯橡胶复合材料（SMt3／CB／SBR）,研究了复合材料的力学性能、热氧老化性能、动态力学性能以及微观形态。结果表明,SMB／CB／SBR复合材料的力学性能优于未改性淀粉／CB／SBR复合材料,拉伸强度及扯断伸长率等性能优于SBR／CB复合材料;且SMB／CB／SBR复合材料具有更好的耐热氧老化性能;与SBR／CB复合材料相比,SMB／CB／SBR复合材料具有更低的滚动阻力;微观形态显示,淀粉经改性后粒子尺寸减小,在SBR基体中的分散性得到改善,与SBR基体的相容性得到提高。     

Preparation and characterization of poly(styrene‐co‐butadiene) and polybutadiene rubber/clay nanocomposites

Poly(styrene‐co‐butadiene) rubber (SBR) and polybutadiene rubber (BR)/clay nanocomposites have been prepared. The effects of the incorporation of inorganically and organically modified clays on the vulcanization reactions of SBR and BR were analysed by rheometry and differential scanning calorimetry. A reduction in scorch time (t_s1) and optimum time (t₉₅) was observed for both the rubbers when organoclay was added and this was attributed to the amine groups of the organic modifier. However, t_s1 and t₉₅ were further increased as the clay content was increased. A reduction in torque value was obtained for the organoclay nanocomposites, indicating a lower number of crosslinks formed. The organoclays favoured the vulcanization process although the vulcanizing effect was reduced with increasing clay content. The tensile strength and elongation of SBR were improved significantly with organoclay. The improvement of the tensile properties of BR with organoclay was less noticeable than inorganic‐modified clay. Nevertheless, these mechanical properties were enhanced with addition of clay. The mechanical properties of the nanocomposites were dependent on filler size and dispersion, and also compatibility between fillers and the rubber matrix. Copyright © 2004 Society of Chemical Industry     

Effects of antimicrobial agents on the processing and performance properties of rubber material formulations with no cytotoxicity

The present work aims to develop antimicrobial rubber for safe industrial toys. For this purpose, natural rubber (NR) and synthetic rubber as styrene butadiene rubber (SBR) and ethylene propylene diene monomer (EPDM) were examined. Rubber and their ingredients as well as antimicrobial agents (doxycycline and cephalexin) were mixed in a rubber mixer. The rheological properties of compounded rubber were studied, and the curing time was determined. Mechanical properties and cytotoxicity were evaluated at optimally cured rubber compounds. Scanning electron micrographs of vulcanizates showed good dispersion of ingredients throughout the investigated matrices. Rheology study for the investigated vulcanizates in presence of tested antimicrobial species exhibited no significant change in their flow behaviors. It is significant to remember that the desired physical characteristics of rubber products, including their chemical and mechanical characteristics (elongation at break and tensile strength) enhanced when doxycycline and cephalexin are present, depending on their nature and concentration. Similar results were obtained for both the SBR and EPDM rubber vulcanizates. The cytotoxicity of the prepared vulcanizates towards human normal retina cell line (RPI-1) indicated good safety of these rubber products. Furthermore, developed rubber vulcanizates showed good antimicrobial efficacy towards the test bacteria and fungi strains.”     

Synergic effect of N‐benzylimine aminothioformamide secondary accelerator during sulfur vulcanization of a styrene‐butadiene‐natural rubber blend

In this study we reported synergic activity of a novel secondary accelerator N‐Benzylimine aminothioformamide (BIAT) along with tetramethylthiuram disulfide (TMTD) in improving cure and mechanical properties of gum and filled mixes of Styrene‐Butadiene Rubber (SBR). The feasibility of application of BIAT in sulfur vulcanization of an ideal blend of SBR and natural rubber (NR) has also been investigated. The mechanical properties like t ensile strength, tear resistance, hardness, compression set, and abrasion loss were measured. Swelling values were also determined as a measure of crosslink densities of the vulcanizates. The binary accelerator system BIAT‐TMTD was found very effective in improving cure properties of the mixes of pure SBR and a 50/50 blend of SBR and NR.There was also found simultaneous improvement in mechanical properties of vulcanizates of both pure and blend. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

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     

改性淀粉对炭黑填充丁苯橡胶/顺丁橡胶并用胶性能的影响

用改性淀粉替代部分炭黑填充丁苯橡胶(SBR)/顺丁橡胶(BR)并用胶,考察了改性淀粉用量及偶联剂种类对混炼胶硫化特性及硫化胶物理机械性能和动态力学性能的影响.结果表明,用改性淀粉替代部分炭黑可对SBR/BR混炼胶的硫化产生明显的延迟作用,但改性淀粉用量的变化对焦烧时间与正硫化时间影响不大;添加偶联剂KH-570或NDZ-201延迟了混炼胶的硫化过程,KH-550能大幅度地促进硫化作用,Si-69对于体系的硫化性能略有影响;随着改性淀粉用量的增加,SBR/BR硫化胶的拉伸性能、耐磨耗性均有所降低,但弹性、动态生热和滞后性能得到了明显改善,改性淀粉最佳用量为5～8份;各种偶联剂均可提高SBR/BR硫化胶的拉伸性能,硅烷偶联剂Si-69和KH-570对弹性和动态生热也略有改善,添加偶联剂KH-550改善了SBR/BR硫化胶的抗湿滑性能,但滞后性能变差,添加偶联剂KH-570或Si-69对SBR/BR硫化胶动态力学性能的影响较小,综合考虑,以添加偶联剂KH-570较好.     

Effect of pulverized coal/carbon black hybrid fillers on mechanical properties and thermal stability of styrene butadiene rubber composites

Pulverized coal (coal) possesses a layered structure similar to graphite and is a potential reinforcing filler. In this paper, ball milling is used to reduce the particle diameter of coal. The coal is modified with KH-560 to obtain K-COAL and prepared K-COAL/styrene-butadiene rubber (SBR) composites. In addition, carbon black (CB) is modified to obtain CB-Si69, K-COAL and CB-Si69 are added to SBR in different ratios to prepare COAL/CB/SBR composites. The results show that the addition of K-COAL can improve the vulcanization performance, thermal stability, and mechanical properties of SBR composites, but the reinforcing effect is weak. In the COAL/CB/SBR composites, the vulcanization and mechanical properties of the composites gradually increase with the increase of CB, while those of the thermal stability decrease. The tensile strength of the 10 phr COAL/30 phr CB/SBR composite is 24.1 MPa, which is elevated by 1105% and 205% compared with the pure SBR and 40 phr K-COAL/SBR composites, respectively. The composites maintain high elasticity while the tensile strengths are greatly improved, and the mechanical properties are significantly enhanced. In conclusion, this paper provides a reference for the clean utilization of coal and shows new possibilities for finding new fillers to replace CB.     

Co-compatibilising effect of carbon nanotubes and liquid isoprene rubber on carbon black filled natural rubber/polybutadiene rubber blend

Abstract

Bis-(triethoxysilylpropyl)-tetrasulfane functionalised carbon nanotubes (t-CNTs) were used as compatibiliser along with liquid isoprene rubber (LIR) in the natural rubber (NR)/polybutadiene rubber (BR) blend. Their reinforcing and compatibilising effects were evaluated by mechanical, fatigue crack growth resistance properties and blend homogeneity. Scanning electron microscope and transmission electron microscope showed enhanced interfacial adhesion between the binary rubber phases and improved dispersion of the minor phase in the rubber blend respectively with the co-existence of LIR and carbon nanotubes. The tensile strength of the carbon black (CB) filled NR/BR blend reached its optimum when 3 phr CB was replaced with an equal amount of t-CNTs in the presence of 7 phr LIR, while the fatigue crack growth resistance property achieved its maximum in the presence of 3 phr LIR. This interesting co-compatibilisation behaviour of t-CNTs and LIR suggests that t-CNTs have a better effect than CB with the assistance of LIR, which is an effective plasticiser in the NR/BR blend.     

Studies on preparation and properties of vinyltriethoxysilane‐grafted styrene‐butadiene rubber

Graft polymerization of vinyltriethoxysilane (VTES) onto styrene‐butadiene rubber (SBR) was carried out in latex using benzoic peroxide (BPO) as an initiator. The concentration of VTES effecting on vulcanization characteristics, mechanical properties and thermal properties of VTES‐grafted SBR (SBR‐g‐VTES) were investigated. The grafting of VTES onto SBR and its pre‐crosslinking were confirmed by attenuated total teflectance‐Fourier transform infrared reflectance and proton nuclear magnetic resonance. The mechanism of graft polymerization was studied. The results revealed that the minimum torque, optimum cure time, tensile strength, thermal decomposition temperature, and glass transition temperature (T_g) all increased with the increasing concentration of VTES. But the grafting efficiency of VTES, rate of vulcanization, and elongation at break of the SBR‐g‐VTES decreased. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Surface modification of MWCNT to improve the mechanical and thermal properties of natural rubber nanocomposites

In this study, we focused on the synergistic effect between carbon black (CB) and multiwall carbon nanotube (MWCNT) hybrid fillers. In particular, the surface modification of pristine MWCNT (P-MWCNT) via an acid (oxidation) treatment was used to improve their dispersion, as well as the mechanical and thermal properties of their corresponding natural rubber (NR)-based nanocomposites. Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM) were carried out to determine the presence of functional groups on the oxidized MWCNT (O-MWCNT). After vulcanization, dynamic mechanical analysis (DMA), tensile properties, hardness, thermal conductivity, swelling behaviour in toluene and SEM characterizations were performed on both NR/CB/P-MWCNT- and NR/CB/O-MWCNT-based nanocomposites. The results showed the positive effect of MWCNT surface oxidation on the fillers' dispersion and nanocomposites' properties.     

Adhesion of flame-treated polyolefins to styrene butadiene rubber

Samples of polyethylene and polypropylene have been submitted to repeated short duration (75 ms) flame treatments, at optimum flaming conditions. Surface energies of untreated and flamed specimens were determined by liquid contact angle measurements. It appears that the surface energy of polyethylene increases much more than that of polypropylene after flame treatment. The flamed polymer surfaces were further examined by electron spectroscopy, Fourier Transform IR spectroscopy and secondary ions mass spectrometry. The adhesion properties of modified polymer surfaces were studied by testing in peel the bonded Styrene Butadiene Rubber/polyolefins assemblies. Scanning electron microscopy (SEM) and water contact angle measurements have been used to observe the locus of failure. Good correlations were obtained between surface energy and adhesion strength, the increase in adhesion strength being particularly important for flamed PE/SBR assemblies. In addition, the peeling in a liquid medium allowed the determination of the respective contribution to adhesion of chemical and physical interactions. It is shown that a major part of the adhesion strength increase is of chemical origin, particularly for the bonded flamed PE/SBR assemblies.     

天然橡胶/顺丁橡胶/丁苯橡胶自润滑喷蜡橡胶材料的性能

在天然橡胶(NR)/顺丁橡胶(BR)/丁苯橡胶(SBR)为基体的自润滑喷蜡橡胶材料中加入芥酸酰胺,考察芥酸酰胺作为润滑剂时对NR/BR/SBR自润滑喷蜡橡胶材料的硫化特性、力学性能、门尼黏度、摩擦系数及耐老化性能的影响。结果表明,与未加芥酸酰胺的胶料相比,当芥酸酰胺用量为10份时,胶料转矩减小,焦烧时间和正硫化时间缩短,扯断伸长率从388%增加至523%,拉伸强度降低了21.36%,邵尔A硬度、压缩永久变形分别下降5.56%和8.74%,动、静摩擦系数分别减小23.46%和24.82%,门尼黏度降低20.89%,耐热氧老化性能下降。硫化胶拉伸100%停放5 min后,表面出现明显的白色润滑膜,胶料流动性变好,各组分分散得更均匀,断面更光滑。     

Preparation and properties of styrene‐butadiene rubber nanocomposites blended with carbon black‐graphene hybrid filler

Graphene has become an attractive reinforcing filler for rubber materials, but its dispersion in rubber is still a big challenge. In this work, a novel carbon black‐reduced graphene (CB‐RG) hybrid filler was fabricated and blended with styrene‐butadiene rubber (SBR) via simple two‐roll mill mixing. The prepared CB‐RG hybrids had a microstructure with small CB agglomerates adsorbed onto graphene surfaces. CB acted as a barrier preventing the RG sheets from restacking even after drying. Homogeneous dispersion of graphene sheets in SBR matrix was observed by the mechanical mixing method based on the application of the CB‐RG hybrid fillers. Dynamic mechanical analysis showed that Tg of the SBR/CB‐RG blend was higher than that of the SBR/CB blend indicating strong interfacial interactions between RG and SBR due to the high surface area of graphene and the π‐π interaction between SBR and graphene. The tensile properties of SBR/CB‐RG composites improved significantly and the volume resistivity decreased compared with the SBR/CB blends. The thermal stability of SBR composites filled with CB and CB‐RG showed slight difference. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41309.