Latex interpenetrating polymer networks based on high styrene resin

Latex interpenetrating polymer networks based on high styrene resin (“HSR300”) as seed latex and polystyrene as the second polymer have been synthesized in different compositional ratios. The morphology of resultant materials was determined by field emission electron microscopy, atomic force microscopy, transmission electron microscopy, and by dynamic mechanical analysis. A polystyrene (PS) rich shell is observed in the latex particles. At higher second polymer ratios, a PS‐rich shell can be resolved, but in general the majority of the polymer is incorporated as domains within each particle. The two crosslinked polymers are well intermeshed at the microscopic level, as reflected not only by morphology but also by single tan δ peaks in dynamic mechanical analysis (DMA) data. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 622–628, 1999     

丁苯橡胶生产及市场分析

综述了国内外丁苯橡胶（SBR）的生产及市场情况,对国内SBR的市场发展趋势进行了分析。并预测在世界金融危机的影响下,国内SBR需求增长将会放缓,而国内产能的猛增,将加剧SBR产能过剩,造成供过于求的局面。此外,本文还对国内SBR行业存在的不足提出了几点建议。     

丁苯橡胶生产及市场分析

综述了国内外丁苯橡胶的生产及市场情况,对国内丁苯橡胶的市场发展趋势进行了分析。此外,还对国内丁苯橡胶行业存在的不足提出了几点建议。     

Sequential interpenetrating polymer network of poly(ethyl methacrylate) and carboxylated nitrile rubber: Dynamic mechanical analysis and morphology

An interpenetrating polymer network (IPN) based on poly(ethyl methacrylate) (PEMA) and carboxylated nitrile rubber was synthesized. Peroxide crosslinked XNBR was swollen in ethyl methacrylate containing benzoyl peroxide as initiator and tetraethylene glycol dimethacrylate as crosslinking agent. A full and sequential IPN is formed by the two independently crosslinked phases of XNBR and PEMA. Dynamic mechanical analysis of the 50/50 XNBR/PEMA IPN shows a single, broad peak whereas a 50/50 blend shows two distinct peaks, indicating the pinning down of a microheterogeneous structure during the IPN formation rather that macrophase separation as in blends. SEM analysis confirms the development of a cocontinuous intimate structure of the IPN. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1487–1491, 2005     

SMC晶须在丁苯橡胶中的应用

对硅镁钙晶须（SMC晶须）在丁苯橡胶（SBR）中的应用进行了研究,考察了晶须用量（0～50phr）对胶料的硫化特性和硫化胶的力学性能的影响,并与常用的填料白炭黑（WCB）和碳酸钙（CaCO3）进行了比较。实验结果表明：SMC晶须对SBR有促进硫化作用;SMC晶须对SBR具有一定的补强作用,拉伸强度随着晶须用量的增加而增大;用量相同时,SMC晶须填充的复合材料硬度和撕裂强度与WCB填充的相当,300%定伸应力比WCB填充的高,拉伸永久变形比WCB小得多;SMC晶须补强效果远优于CaCO3。     

提高聚合温度增产的研究

研究了乳液聚合丁苯橡胶(ESBR)合成工艺中不同聚合反应温度及引发剂用量对聚合反应速率的影响.实验结果表明,在聚合反应温度提高至8℃,控制聚合反应速率基本不变的条件下,可降低10%引发剂用量,减少制冷量,而橡胶的凝胶含量及分子量分布正常,产品物性达到优级品指标.     

提高转化率对乳聚丁苯橡胶性能的影响

以吉林石化公司有机合成厂的乳聚丁苯橡胶(SBR)生产配方为标准配方,研究了聚合反应时间对转化率的影响,分析了提高转化率对SBR的生胶门尼黏度、结合苯乙烯含量、凝胶含量、相对分子质量及其分布、胶乳黏度等基本性能的影响。结果表明,在标准配方条件下,延长聚合反应时间,转化率可以达到70%。转化率为70%时所得SBR与转化率为62%时所得SBR相比,前者的生胶凝胶含量和胶乳黏度均增大了1倍,数均相对分子质量、重均相对分子质量和Z均相对分子质量均高于后者,相对分子质量分布变宽,且前者的生胶结合苯乙烯含量能够达到产品标准,而生胶门尼黏度和在50 m in时的300%定伸应力偏高于产品优级品要求。     

基于BP神经网络优化制备化学改性脱硫灰/丁苯橡胶复合材料

以化学改性脱硫灰取代部分炭黑与丁苯橡胶复合制备化学改性脱硫灰/丁苯橡胶复合材料,运用均匀设计结合BP神经网络建立制备工艺参数与力学性能的BP神经网络优化模型,获得制备最优化学改性脱硫灰/丁苯橡胶复合材料的工艺参数,对最优复合材料进行了表征. 结果表明,最优化学改性脱硫灰/丁苯橡胶复合材料的制备参数为促进剂N-叔丁基-2-苯并噻唑次磺酰胺用量1.2 g、硫磺用量1.3 g、硬脂酸用量1.1 g、氧化锌用量2.4 g、硫化时间27 min,该条件下所制复合材料的拉伸强度为20.31 MPa、撕裂强度为45.68 kN/m、邵氏A硬度为66,最优实测值与最优模型预测值吻合较好,相对误差为3.03%~3.22%.     

Novel green composites from styrene butadiene rubber and palm oil derivatives for high performance tires

In rubber compounding, renewable, nontoxic, and degradable palm oil is used as a safe alternative softener or stabilizer process oil. In the tire industry, with the development of environment-friendly “green tires,” silica has been used as a reinforcing filler for tread compounds. To make the hydrophilic silica compatible with the hydrophobic rubber matrix, the addition of amphiphilic oil is required. We, for the first time, prepared an amphiphilic palm oil derivative (PO) with hydrophobic and hydrophilic functional groups in bulk. Rubber composites prepared with the PO exhibited remarkable improvements in mechanical properties, including tensile strength, elongation, and fatigue. These improvements are attributed to the enhanced dispersion of the fillers in the rubber matrix due to the PO. Also, the mixing of PO in the rubber matrix resulted in outstanding abrasion, rebound resilience, and heat buildup properties at low loadings. We then prepared pneumatic tires with a tread composite using PO, and conducted virtual tests using a vehicle-mounted pneumatic tire. The pneumatic tire exhibited enhanced high speed durability, dry and wet braking. The strong interfacial interactions between the silica and the rubber matrix due to the PO resulted in improved viscoelastic properties. These results show that PO is a renewable potential replacement for conventional aromatic oils in tire engineering applications. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47672.     

Effect of liquid isoprene rubber on dynamic mechanical properties of emulsionpolymerized styrene/butadiene rubber vulcanizates

The effect of liquid isoprene rubber (LIR) on the dynamic mechanical properties of emulsion‐polymerized styrene/butadiene rubber (ESBR) vulcanizates was investigated by temperature sweep using dynamic mechanical analysis. The introduction of LIR led to ESBR vulcanizates having higher loss factor (tan δ) in the temperature range ? 30 to 0 °C, and lower tan δ in the range 60 to 80 °C. A small amount of LIR‐403 (LIR with carboxyl groups) led to a significant change in tan δ: the addition of LIR‐403 (3 phr) led to a 7.5% increase in tan δ from ? 30 to 0 °C, and a 24.9% decrease in tan δ from 60 to 80 °C. It was found that the introduction of LIR increased the bound rubber content in the ESBR compound. Equilibrium swelling experiments showed that the crosslink density of the vulcanizates increased after the introduction of LIR‐403 or LIR‐50 (general purpose LIR). The change in tan δ from 60 to 80 °C was related to polymer–filler interactions. The characteristic constant of filler–ESBR matrix interaction (m) was calculated. At a given filler volume fraction, the increase in m in the presence of LIR could be well related to the decrease in tan δ from 60 to 80 °C. The influence of LIR on filler network in the ESBR compound was also investigated by strain and temperature sweeps using a rubber processing analyzer. Copyright © 2011 Society of Chemical Industry     

Interpenetrating polymer networks based on nitrile rubber and metal methacrylates

Interpenetrating polymer networks (IPNs) based on nitrile rubber (NBR) as first component and zinc dimethacrylate (ZnDMA), aluminum trimethacrylate (AlTMA), or zirconium tetramethacrylates (ZrTeMA) as second component were synthesized. Sequential IPNs (SeqIPN) were formed by two routes such as compression molding (CM) and swelling/curing (SC). The IPNs were found to have superior properties compared to metal oxide/hydroxide‐filled NBR. Tensile strength has increased to a large extent while maintaining appreciable elongation. Total crosslink density (covalent and ionic) was found to increase in the order NBR/metal oxide or hydroxide < SeqIPN(CM route) < SeqIPN (SC route). IPNs are found to retain high storage modulus even in the rubbery region. It is observed that change of technique for IPN formation has drastically changed the modulus of the present system. Decrease in tan δ value and inward shifting of peaks were observed because of IPN formation. Morphology of SeqIPN by SC process was found to be more uniform compared to others. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 2542–2548, 2006     

橡胶助剂Silane-M对丁苯橡胶/白炭黑复合材料硫化性能的影响

用硫化仪考察了橡胶助剂3-苯并噻唑硫代-1-丙基-三乙氧基硅烷(Silane-M)对丁苯橡胶/白炭黑复合材料硫化性能的影响.结果表明,Silane-M可明显缩短丁苯橡胶/白炭黑复合材料的正硫化时间,但不影响其焦烧时间.Silane-M具有一定的促进作用,可以加快硫化速率.未添加和添加6份(质量)Silane-M的丁苯橡胶/白炭黑复合材料在135～160 ℃的硫化温度系数和硫化反应表观活化能均比较接近,2种复合材料的硫化性能对温度的依赖性基本一致.     

提高乳聚丁苯橡胶转化率的影响因素

以吉林石化公司生产的丁苯橡胶(1500)为研究对象,以12 h内聚合转化率达到(70±2)%、产品性能与转化率为(62±2)%者相当为目标,研究了引发剂、相对分子质量调节剂、电解质、单体配比与纯度及乳化剂等对丁苯橡胶聚合的影响,测定了不同转化率丁苯橡胶胶乳的机械稳定性及丁苯橡胶生胶和硫化胶的性能。结果表明,在不改变原材料品种和规格的前提下,于氧化剂用量110%(以标准配方所用质量为100%计,下同)、还原剂用量100%和助还原剂用量110%,硫醇初始量与补加量的质量比为100/20、补加时机在反应开始后2 h,电解质用量为110%~115%、初始时一次加入,丁二烯与苯乙烯的质量比为(72.0/28.0)~(72.5/27.5),乳化剂初始量与补加量的质量比为100/10、补加时机在反应开始后2 h的条件下,在12 h内可以使丁苯橡胶1500的聚合转化率提高到(70±2)%,并确保其产品性能全部达到国标优级品标准。     

Natural rubber–styrene butadiene rubber latex blends: Time-dependent rheological behavior and film formation

This article focuses mainly on the effect of maturation time on the rheological behavior of unvulcanized natural rubber (NR)–styrene butadiene rubber (SBR) latex blends. Viscosity shows a composition-dependent behavior with maturation time. It was found that there is a marginal decrease in viscosity for all the systems with maturation time except for the 70/30 NR–SBR blend. In this blend, there is a sharp decrease in viscosity with maturation time. This is associated with the exchange of stabilizers with one another until an equilibrium is reached; that is, all the particles of the blend are stabilized with random mixture of stabilizers. The structural build up observed in 70/30 NR–SBR blend was found to be diminished as the maturation time increases. At equilibrium, there is no further exchange of stabilizers. The behavior of this blend has been explained with the help of a schematic model. The effects of blend ratio and surface active agents on the viscosity were also studied. In addition, the time-dependent flow behavior of prevulcanized latex blends was evaluated as a function of vulcanizing systems and prevulcanization time. There is a regular increase in viscosity with prevulcanization time. However, after 3 h, the viscosity of almost all blends levels off, indicating that the curing reaction is complete within this time. Finally, the morphological changes occurred during film formation of the blends were studied using scanning electron microscopy. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68: 1473–1483, 1998     

Correlation between mechanical damping and interphase content in interpenetrating polymer networks

Recently, some interpenetrating polymer networks with good mechanical damping properties have been synthesized. However, the effect of morphology on this property has not yet been clearly elucidated. Herein, two polystyrene–polyurethane interpenetrating polymer networks, which were grafted using TMI [benzene‐1‐(1‐isocyanato‐1‐methyl ethyl)‐3‐(1‐methylenyl)] and HEMA (2‐hydroxyethyl methacrylate), respectively, have been investigated, as model samples, by modulated‐temperature differential scanning calorimetry and by dynamical mechanical thermal analysis. The results indicate that there is a correlation between mechanical damping and both interphase content and the distribution of composition in the interphase region. The findings should provide valuable information for the design of future damping materials. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2439–2442, 2001     

用甲酸-过氧化氢法制备环氧化丁苯橡胶

以聚乙二醇为相转移催化剂,采用甲酸-过氧化氢法制备了环氧化丁苯橡胶(SBR),研究了聚乙二醇/SBR(质量比)、甲酸/SBR(质量比)、过氧化氢/甲酸(摩尔比)、SBR质量浓度、反应温度、反应时间的影响,并用红外光谱法及核磁共振法对其结构进行了表征。结果指出,相转移催化剂聚乙二醇可提高SBR的环氧化程度。最佳环氧化反应条件为:聚乙二醇/SBR0·05,甲酸/SBR0·15,过氧化氢/甲酸1·0~1·2,SBR质量浓度0·11g/mL,反应温度70℃,反应时间4h。     

改性碱式氯化镁晶须/丁苯橡胶复合材料制备与性能研究

以工业活性轻烧氧化镁粉和盐酸为原料,采用水溶液法制备了碱式氯化镁晶须,继而采用硅烷偶联剂对碱式氯化镁晶须进行改性,然后将其与丁苯橡胶混炼得到改性碱式氯化镁晶须/丁苯橡胶复合材料,研究了改性碱式氯化镁晶须对丁苯橡胶力学性能及热学性能的影响。结果表明：采用水溶液法制备得到的碱式氯化镁晶须结构为Mg₂（OH）₃Cl·4H₂O,呈微细纤维状,分布较均匀,长径比大于20;改性碱式氯化镁晶须的加入,可以改善丁苯橡胶的机械强度和阻燃性能。     

Improvement of cutting and chipping resistance of carbon black-filled styrene butadiene rubber by addition of nanodispersed clay

A novel, effective approach to improve the cutting and chipping resistance (CCR) of carbon black (CB)-filled styrene butadiene rubber (SBR) composite was reported in this study. CCR of SBR was dramatically improved more than 30% by addition of 4 phr nanodispersed clay (NC), while not decreasing the stress at 100% and the Shore A hardness of the composite. The curing characteristics, loss tangent (tan δ), and the strength of filler network of the composites were further measured by a Disk Oscillating Rheometer and a rubber processing analyzer, respectively. It was found that the addition of NC led to a slightly lower crosslink density, higher tan δ, and stronger filler network, which contributed to the higher CCR. Therefore, the novel layered NC is more efficient in improving CCR when compared with CB. The results are expected to promote the application of NC in rubber industry. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Electrical properties of nanostructured interpenetrating polymer networks based on natural rubber (NR)/polystyrene (PS)

The electrical properties of nanostructured sequential interpenetrating polymer networks from natural rubber (NR) and polystyrene (PS) have been studied in the frequency range of 10²–10⁷ Hz. The permittivity, volume resistivity, dielectric loss factor, and dissipation factor were analyzed as a function of frequency, blend composition, crosslinking level, and initiating system. It was found that the volume resistivity and dissipation factor first increase, reach a maximum around 10³–10⁵ Hz, and then decrease gradually with the increase of frequency. As the NR content is increased from 30 to 70%, the dissipation factor (tan δ) increases. On increasing the extent of the PS phase crosslinking, the permittivity increases. However, at higher levels of PS crosslinking, the permittivity values decrease due to the agglomeration of PS phase arising from excessive crosslinking. The morphology studies using a scanning electron microscope confirmed the agglomeration of PS phase at high crosslinking level. The permittivity values are maximum at 4% of crosslinking content. The influence of initiating system on the dielectric properties was not very significant. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2017–2026, 2005     

Tear and processing behaviour of short sisal fibre reinforced styrene butadiene rubber composites

The tear failure and processing characteristics of short sisal fibre reinforced styrene butadiene rubber (SBR) composites were investigated. Tear strength was examined with special reference to the effects of fibre length, fibre orientation, fibre concentration and bonding agent. It was observed that the tear strength depends on all the above factors. The tear failure mechanism was analysed from fractographs taken using a scanning electron microscope (SEM). During tear testing, the composites failed by a shearing process. Microscopic examination of cracks propagating in SBR composites revealed that the amorphous SBR matrix developed cracks, leaving ligaments of rubber attached to the broken fibres. The rubber particles were stretched as the crack opened and failure occurred at large critical extensions. It was observed that an increase in the concentration of fibres increased the tear strength in both longitudinal and transverse directions. The tear strength values were almost three to four times higher than those of the unfilled vulcanizates under similar conditions. In order to analyse the processing behaviour, the green strength, mill shrinkage and Mooney viscosity of the compounds were determined. Finally, the polymer–filler interaction was studied using the Lorenz–Park and Kraus equations.