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1.
Sung‐Seen Choi 《Polymer International》2001,50(5):524-530
Rheological behaviour and cure characteristics of silica‐filled styrene–butadiene rubber (SBR) compounds and SBR compounds filled with both silica and carbon black with different silica contents were investigated. Rheocurves of the time versus the torque of the compounds showed specific trends with the silica content. For the compounds with low silica content (less than 50 phr), the torque decreased immediately after the steep increase at the initial point of the rheocurve and then increased very slowly. For the compounds with high silica content (more than 50 phr), the rheographs showed two minimum torque points; the torque decreased immediately after the steep increase at the start point of the rheocurve and then increased sharply before reaching the second minimum point. This can be explained by the strong filler–filler interaction of silica. The minimum torque of the compound increased slightly with an increase of the silica content up to 50 phr silica content and then increased appreciably. For the silica‐filled compounds, cure times of the t02, t40, and t90 became shorter with an increase of the filler content. For the compounds filled with both silica and carbon black (total filler content of 80 phr), the cure times became longer with an increase of the silica content ratio. © 2001 Society of Chemical Industry 相似文献
2.
Because silica has strong filler–filler interactions, a silica‐filled rubber compound shows a poor filler dispersion compared to a carbon black‐filled one. Improvement of the filler dispersion in silica‐filled styrene–butadiene rubber (SBR) compounds was studied using low molecular weight polybutadiene (liquid PBD) with the high content of 1,2‐unit. By adding the liquid PBD to the silica‐filled SBR compound, the filler dispersion and flow property are improved. The cure time and cure rate become faster as the 1,2‐unit content of the liquid PBD increases for the compounds containing the liquid PBD. The crosslink density increases linearly with increase in the 1,2‐unit content of the liquid PBD. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3135–3140, 2003 相似文献
3.
Sung‐Seen Choi 《应用聚合物科学杂志》2002,83(12):2609-2616
Because silica has strong filler–filler interactions, a silica‐filled rubber compound is characterized by a poor dispersion of the filler. Properties of silica‐filled natural rubber (NR) compounds were improved using polychloroprene (chloroprene rubber [CR]). The bound rubber content of the compound increases and the filler dispersion is also improved by adding CR to the compound. Physical properties such as modulus, tensile strength, abrasion, and crack resistance are improved by adding CR. Elongation at break of the vulcanizates containing CR is longer than that of the vulcanizate without CR, although crosslink density of the former is higher than that of the latter. The improved physical properties are attributed to the good dispersion of silica by adding CR. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2609–2616, 2002 相似文献
4.
Sung‐Seen Choi 《应用聚合物科学杂志》2001,79(6):1127-1133
Since silica has strong filler–filler interactions and adsorbs polar materials, a silica‐filled rubber compound has a poor dispersion of the filler and poor cure characteristics. Improvement of the properties of silica‐filled styrene–butadiene rubber (SBR) compounds was studied using acrylonitrile–butadiene rubber (NBR). Viscosities and bound rubber contents of the compounds became lower by adding NBR to the compound. Cure characteristics of the compounds were improved by adding NBR. Physical properties such as modulus, tensile strength, heat buildup, abrasion, and crack resistance were also improved by adding NBR. Both wet traction and rolling resistance of the vulcanizates containing NBR were better than were those of the vulcanizate without NBR. The NBR effects in the silica‐filled SBR compounds were compared with the carbon black‐filled compounds. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 1127–1133, 2001 相似文献
5.
The influence of in situ modification of silica with bis‐(3‐(triethoxysilyl)‐propyl)‐tetrasulfide (TESPT) on filler network in silica filled solution SBR compound was investigated. In situ modification greatly increased the bound rubber content. TEM observation of silica gel showed that bridging and interlocking of absorbed chains on the surface of silica particles formed the filler network. Rubber processing analyzer (RPA) was used to characterize the filler network and interaction between silica and rubber by strain and temperature sweeps. In situ modification improved the dispersion of silica, and in the meantime, the chemical bonds were formed between silica and rubber, which conferred the stability of silica dispersion during the processing. Compared to the compound without in situ modification, the compound with in situ modification of silica exhibited higher tan δ at low strains and lower tan δ at high strains, which can be explained in terms of filler network in the compounds. After in situ modification, DMTA results showed silica‐filled SSBR vulcanizate exhibited higher tan δ in the temperature range of ?30 to 10°C, and RPA results showed that it had lower tan δ at 60°C when the strain was more than 3%. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
6.
Silica‐filled styrene–butadiene rubber (SBR) unvulcanizates and their vulcanizates with different rubber/filler interactions were prepared by using several kinds of coupling agents. Tensile tests and electron spin resonance (ESR) measurements were carried out for both unvulcanized and vulcanized samples to get information on the effects of filler/rubber interactions on the breakdown of carbon–carbon (C? C) linkages in SBR and carbon–sulfur (C? S? C, C? S? S? C) linkages at the crosslinked points between rubber and sulfur by a tensile force. The combination of ESR results and stress–strain data suggested that with increasing the mechanical energy applied to the samples by the stretching, the carbon–sulfur linkages around silica particles were broken first, followed by the breakdown of carbon–sulfur and C? C linkages in the rubber matrix. The assignment of ESR spectrum was also discussed. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
7.
Sung‐Seen Choi 《应用聚合物科学杂志》2002,85(2):385-393
Because silica has strong filler‐filler interactions and adsorbs polar materials, a silica‐filled rubber compound exhibits poor dispersion of the filler and poor cure characteristics in comparison with those of a carbon black‐filled rubber compound. Acrylonitrile‐butadiene rubber (NBR) improves filler dispersion in silica‐filled styrene‐butadiene rubber (SBR) compounds. The influence of the NBR type on the properties of silica‐filled SBR compounds containing NBR was studied with NBRs of various acrylonitrile contents. The composition of the bound rubber was different from that of the compounded rubber. The NBR content of the bound rubber was higher than that of the compounded rubber; this became clearer for NBR with a higher acrylonitrile content. The Mooney scorch time and cure rate became faster as the acrylonitrile content in NBR increased. The modulus increased with an increase in the acrylonitrile content of NBR because the crosslink density increased. The experimental results could be explained by interactions of the nitrile group of NBR with silica. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 385–393, 2002 相似文献
8.
Changwoon Nah 《Polymer International》2002,51(3):245-252
The influence of trans‐polyoctylene rubber (TOR) on the flow property, die swell behaviour and green tensile property of NR (natural rubber)/NBR (acrylonitrile–butadiene rubber) blend compound was investigated as a function of TOR loading level. The pure TOR, NR and NBR compounds were also investigated for comparison with the blend compounds. The shear viscosity of TOR strongly depended on the temperature as well as shear rate. The viscosity of the NR/NBR blend compound was even lower than that of the constituent components at relatively lower shear rates, and the viscosity difference became smaller as the shear rate was increased. The viscosity of the NR/NBR blend compounds was strongly affected by the addition of TOR but the effect became negligible with increasing the shear rate. Both the die‐swell ratio and the surface topology of extrudates were also affected by TOR addition; the dependence on shear rate was much stronger for higher TOR level. The NR/NBR blend compound showed much higher green tensile strength and elongation at break than those of the constituent components. Both the green tensile modulus and strength of the NR/NBR blend compound were greatly enhanced, while the elongation at break was reduced with the addition of TOR. © 2002 Society of Chemical Industry 相似文献
9.
The tensile properties of polypropylene (PP) filled with two A‐glass beads with the same size, PP/3000 (glass bead surface pretreated with a silane coupling agent) and PP/3000U (no surface pretreatment), have been measured by using an Instron materials testing machine at room temperature, to identify the effects of the filler surface pretreatment and its content on the tensile properties of these composites. The results show that the Young's modulus Ec of the composites increases non‐linearly with increasing volume fraction of glass beads ϕf, while the tensile yield strength σyc and tensile stress at break σbc of the composites decrease with an increase of ϕf, in the ϕf range 0–30%. Furthermore, the values of Ec and σbc of the PP/3000 system are somewhat higher than those of the PP/3000U system under the same test conditions, but this is in contrast to the tensile strain at break εbc and tensile fracture energy Ebc, especially at higher ϕf values. Good agreement is shown between the measured tensile strength and the predicted value by using an equation proposed in previous work. In addition, εbc and Ebc reach maximum values at ϕf = 25% for both systems. This indicates that there is a brittle–ductile transition for the composites in tension. © 2000 Society of Chemical Industry 相似文献
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Polyethyene glycol (PEG) is widely used as a dispersing agent and can also be used to prevent the adsorption of ingredients on the surface of silica. From the XRD results, PEG that was used as the dispersing agent on the SBR/organoclay compound filled with silica and carbon black (CB) was intercalated between the organoclay layer. Additionally, the interactions with the PEG differed depending on whether 3‐aminopropyltriethoxysilane (APTES) or N,N‐dimethyldodecylamine (DDA) were used as clay modifiers. When PEG was added, the Tg of the SBR/silica/APTES‐MMT compound increased through the formation of hydrogen bonds between the ether linkages of PEG and the hydroxyl groups of APTES. For the SBR/silica/DDA‐MMT compound with PEG, slippage occurred between the silicate, and DDA because of the alkyl chain of DDA. The SBR/silica/APTES‐MMT/CB compound with PEG exhibited the highest Tg value and the highest bound rubber content, with high modulus values at 100 and 300%. The SBR/silica/DDA‐MMT/CB compound had the best properties in terms of the wet skid resistance and the rolling resistance. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 相似文献
12.
A modification of the existing methods for evaluating the dispersive and specific components of surface free energy (γd and γs, respectively) was made to investigate filler–rubber and filler–filler interactions by inverse gas chromatography. Four silicas as fillers and various probes that mimic elastomers were employed in this study. It was shown that the pretreatment of silicas with helium could increase γd and decrease γs. Modification of the silica surface with silane could enhance the dispersive interaction and weaken the specific interaction. The temperature dependence of the interfacial interaction was also investigated, and it was found that lower temperatures favored filler–rubber interactions and mixing efficiency. Tests on different sizes of agglomerates demonstrated the existence of a filler–rubber and filler–filler network. It was also found that γd played a role in agglomeration or filler–filler interaction. Our study showed that the larger the specific surface area was, the stronger the dispersive and specific interactions were. The effectiveness of various fillers and elastomer probes was also compared. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2517–2530, 2001 相似文献
13.
The fatigue resistance of silica‐filled natural rubber (NR) mixes modified with phosphorylated cardanol prepolymer (PCP) was studied in comparison with similar compositions without PCP and with those containing the same dosage of a silane coupling agent (Si‐69). Considerable improvement in the fatigue resistance was observed for the PCP‐modified NR vulcanizate containing 20 phr of silica compared with the unmodified and Si‐69 modified vulcanizates. In addition, the tear strength of the PCP‐modified NR vulcanizate was higher than that of the others. Atomic force microscopy and the scanning electron microscopy of the vulcanizates showed better dispersion of silica particles in the NR matrix in the presence of PCP than in the unmodified and Si‐69‐modified NR vulcanizates. It is assumed that, at a dosage of 5 phr, PCP functions as a coupling agent between NR and the silica particles thereby improving the filler dispersion and consequently the mechanical properties of the vulcanizate. Copyright © 2005 Society of Chemical Industry 相似文献
14.
从力学性能、动态压缩疲劳生热、动态力学性能等方面对比了分别由SnCl_4和SiCl_4偶联的溶聚丁苯橡胶(SSBR)与白炭黑所制备复合材料的性能,并利用测定结合橡胶含量、橡胶加工分析仪及Kraus模型等手段探讨了两种SSBR与白炭黑的相互作用。结果表明,与用SnCl_4偶联所制备的SSBR相比,经SiCl_4偶联制得的SSBR与白炭黑的相互作用力更强,白炭黑的分散性更好。所制备SSBR/白炭黑复合材料的力学性能更好,压缩温升更低,滚动阻力更小,抗湿滑性能更好。 相似文献
15.
含硫硅烷偶联剂对白炭黑填充天然橡胶填料网络结构及流变行为的影响 总被引:4,自引:0,他引:4
通过橡胶加工分析仪研究了分别添加偶联荆双(三乙氧基丙基硅烷)四硫化物(TESPT)、双(三乙氧基丙基硅烷)二硫化物(TESPD)、3-丙酰基硫代-1-丙基-三甲氧基硅烷(PXT)的白炭黑填充天然橡胶(NR)混炼胶的填料网络结构,考察了3种偶联剂对白炭黑填充NR混炼胶的门尼黏度及流变形为的影响.结果表明,3种偶联剂均使白炭黑填料网络化程度大幅度减轻,弹性模量和损耗模量变小,Payne效应大大减弱,增大了胶料的流动性,改善了加工性能;PXT与TESPT比TESPD更能有效地减轻填料的网络化程度. 相似文献
16.
通过研究补强材料白炭黑以及助剂偶联剂对导电橡胶力学性能的影响分析,发现白炭黑和偶联剂的加入均可有效增强导电橡胶的力学性能,且对导电橡胶的导电性影响不大。当白炭黑添加量为15%,偶联剂的添加量为0.7%时,力学性能相对最佳。此外,还研究了导电橡胶的高温环境适应性,发现在高温96 h内,导电橡胶的力学性能以及导电性能可保持相对较佳的状态。 相似文献
17.
Curing characteristics, tensile properties, morphological studies of tensile fractured surfaces using scanning electron microscopy (SEM), and the extent of rubber filler interactions of rattan‐powder‐filled natural rubber (NR) composites were investigated as a function of filler loading and silane coupling agent (CA). NR composites were prepared by the incorporation of rattan powder at filler loading range of 0–30 phr into a NR matrix with a laboratory size two roll mill. The results indicate that in the presence of silane CA, scorch time (ts2), and cure time (t90) of rattan‐powder‐filled NR composites were shorten, while, maximum torque (MH) increased compared with NR composites without silane CA. Tensile strength and tensile modulus of composites were enhanced whereas elongation at break reduced in the presence of silane CA mainly due to increase in rubber‐filler interaction. It is proven by SEM studies that the bonding between the filler and rubber matrix has improved. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 相似文献
18.
采用阳离子乳化剂聚二烯丙基二甲基氯化铵(PDDA)对氨基硅溶胶进行改性制备改性氨基硅溶胶(MSS),然后将其与天然乳胶(NRL)进行杂凝聚制得MSS/NRL膜材料,分析了MSS,MSS/NRL膜材料的结构、粒径、Zeta电位及形态,考察了MSS/NRL膜材料的力学性能及耐紫外老化性能。结果表明,MSS与NRL共混后粒径较NRL增大;氨基硅溶胶经PDDA改性后呈弱正电性,能在杂凝聚共混环境下与带负电荷的乳胶粒子形成多层次核-壳结构;随着MSS添加量的增加,MSS/NRL膜材料的拉伸强度呈先增后减的趋势,当MSS质量分数为0.35%时,膜材料的拉伸强度达到21.98 MPa的最大值,扯断伸长率达到750%;MSS/NRL薄膜的耐紫外老化性能在老化12 h以后较NRL薄膜提高10%以上。 相似文献
19.