橡胶-填料相互作用对丁苯橡胶/白炭黑复合材料性能的影响

本文研究了硅烷偶联剂原位改性白炭黑对溶聚丁苯橡胶(SSBR)性能的影响,结果表明,通过哈克转矩流变仪对含有偶联剂的SSBR/白炭黑混炼胶进行原位热处理后可明显减弱混炼胶的Payne效应,改善白炭黑在橡胶基体中的分散.原位热处理方法能够明显提高硫化胶的300%定伸应力,降低动态压缩温升,同时可使硫化胶在0℃附近具有较高的损耗因子(tanδ),60℃附近具有较低的tanδ.对不同聚合方式得到的丁苯橡胶,即溶聚丁苯橡胶与乳聚丁苯橡胶(ESBR)/白炭黑复合材料的力学性能及动态力学性能进行了研究,结果表明,白炭黑在SSBR2305中分散效果优于在ESBR1502中;采用偶联剂原位改性白炭黑可以使SSBR2305硫化胶获得与ESBR1502硫化胶相当的物理机械性能,更理想的动态力学性能,从而得到力学性能、抗湿滑性、滚动阻力及耐磨性更加均衡的理想轮胎材料.通过对具有不同偶联效率的SSBR/白炭黑体系的微观结构与性能研究发现,随偶联效率的增加,其结合橡胶含量增加,Payne效应减弱;高偶联效率的S-SBR具有较低的动态压缩温升及较好的耐磨性.     

TBIR应用于航空胎侧胶的热氧老化性能

研究了反式-1,4-丁二烯-异戊二烯共聚橡胶(TBIR)应用于航空轮胎胎侧胶[天然橡胶(NR)/顺丁橡胶(BR)/TBIR]的耐热氧老化性能.结果表明,与NR/BR硫化胶相比,10～20份质量的TBIR取代BR后,NR/BR/TBIR硫化胶的交联密度明显提高,压缩温升降低2. 2～3. 4℃,耐屈挠疲劳性能提高约100%,填料分散性改善,填料团聚体体尺寸减小,拉伸性能基本不变.随热氧老化时间延长,硫化胶的交联密度先增加后降低,并用TBIR的硫化胶交联密度在老化48 h后趋于平缓.与NR/BR相比,老化后的NR/BR/TBIR硫化胶生热最低,耐屈挠疲劳性最高.     

大麻纤维增强天然橡胶的制备及其生热现象研究

论文研究了大麻纤维(HF)不同的改性方式对天然橡胶增强效果的影响,通过使用大麻纤维来减少体系中的炭黑含量,在保证橡胶材料具有一定的力学性能的同时,降低大麻纤维增强天然橡胶(HF/CB/NR)复合材料的生热.结果 表明:通过力学性能测试,表明加入一份碱处理的大麻纤维可以减少体系中3份炭黑,表现为二者材料的力学性能相当.通...     

TBIR改性BIIR/NR共混物的结构与性能

研究了新型合成橡胶——高反式-1,4-丁二烯-异戊二烯共聚橡胶(TBIR)对全钢轮胎气密层并用橡胶——溴化丁基橡胶(BIIR)/天然橡胶(NR)(质量比70/30)的改性作用,探讨了BIIR/NR/TBIR共混物的交联密度、填料分散性及力学性能,特别是并用硫化胶的气密性及屈挠疲劳性能等.结果表明,与无定型的BIIR和NR相比,结晶性TBIR的引入提高了炭黑填充的BIIR/NR/TBIR混炼胶的强度和模量,且随着TBIR用量的增大,混炼胶中TBIR的结晶熔融峰更明显,混炼胶的强度与模量显著提高.硫化特性结果表明,随着TBIR用量的增大,BIIR/NR/TBIR共混物的硫化速率略有提高,交联密度略有降低;TBIR用量为10~30份(生胶总质量的10%~30%)时,BIIR/NR/TBIR硫化胶在机械性能基本保持不变的情况下,耐热氧老化性能提高10%以上,耐一级屈挠疲劳性能提升2~5倍,气密性提高17%.炭黑分散结果表明,经过动态疲劳实验BIIR/NR硫化胶中炭黑聚集体的平均粒径增大至11.5μm,明显大于BIIR/NR/TBIR硫化胶中炭黑聚集体的平均粒径.对含TBIR硫化胶在周期性应力应变过程中的结构演变及对耐疲劳裂纹引发性能的影响机制进行了探讨,结果表明,TBIR可改性BIIR或者BIIR/NR制备高抗裂口引发的全钢轮胎气密层材料.     

反式丁戊橡胶改性航空轮胎侧胶的结构与性能

采用反式-1,4-丁二烯-异戊二烯共聚橡胶（简称反式丁戊橡胶,TBIR）改性航空轮胎侧胶[天然橡胶（NR）/顺丁橡胶（BR）（质量比80/20）],研究了NR/BR/TBIR混炼胶的结晶行为、力学性能、硫化特性及硫化胶的物理机械性能、动态力学性能和填料分散性.结果表明,相比NR/BR并用胶,结晶性TBIR的并用赋予NR/BR/TBIR混炼胶较高的格林强度和杨氏模量.NR/BR/TBIR混炼胶工艺正硫化时间延长,交联密度提高.TBIR用量范围内,NR/BR/TBIR硫化胶300%定伸应力提高7%,耐屈挠疲劳性能提高35%~50%,滚动阻力降低.m（NR）/m（BR）/m（TBIR）为80/10/10硫化胶具有更好的综合力学性能及耐热氧老化性能.随着硫化时间的延长,NR/BR/TBIR（80/10/10）硫化胶较NR/BR（80/20）硫化胶100%定伸应力提高18%以上,NR/BR体系的耐屈挠疲劳性降低近60%,而NR/BR/TBIR（80/10/10）体系仍能保持原来的50%;反映滚动阻力的60℃损耗因子降低8%~14%,反映抗湿滑性的0℃损耗因子保持不变.填料分散度得到改善,填料聚集体尺寸降低.NR/BR/TBIR（80/10/10）硫化胶具有更好的耐长时间硫化的特性.     

尼龙短纤维/白炭黑填充天然橡胶的流变与动态力学行为

以尼龙短纤维(NSF)增强天然橡胶(NR)混炼胶为研究体系,以马来酸酐接枝天然橡胶(MNR)为增容剂,考察增容剂、NSF含量对NR/NSF母胶动态流变行为的影响;将NR/NSF母胶加入30份白炭黑(Si O2)填充NR混炼胶中,对比研究NR/NSF、NR/NSF/Si O2混炼胶的线性与非线性流变行为及动态力学行为,采用修正的两相模型分析"粒子相"的增强作用,探讨硫化胶储能模量E'和损耗因子tanδ的变化.结果表明,MNR影响NSF在基体中的分散性和NSF/NR混炼胶的动态流变行为;高填充Si O2和少量NSF之间存在协同增强作用,使NR/NSF/Si O2混炼胶的补强因子和应变放大因子均高于NR/NSF混炼胶,显著增加"粒子相"的黏性与弹性贡献,限制"粒子相"的松弛;硫化胶的E'和tanδ峰值随NSF体积分数增加分别升高和降低.     

利用高压水射流技术制备天然橡胶复合材料

首先利用超声空化作用将炭黑团聚体破碎、切割、分散在水中制得炭黑悬浮液,然后在高速射流场中,炭黑悬浮液被高速射流卷吸到天然胶乳中,在射流边界,由于二者存在极大的速度差,而形成一个湍流混合层,炭黑在湍流拉伸、剪切作用下微观分散到天然胶乳中.结果表明,与传统干法工艺相比,射流工艺可以使炭黑更均匀的分散到天然橡胶基体中.Payne效应结果表明射流工艺减弱了炭黑与炭黑之间的相互作用,增强了炭黑与橡胶之间的相互作用.同时射流工艺制备的复合材料硫化时间变短,硫化程度增加,硫化胶的撕裂强度提高了78%,回弹性提高了20%,DIN磨耗减小了33%.动态力学性能结果表明,射流工艺制备的复合材料在60℃左右具有更低的损耗因子.     

不同硫化体系天然橡胶复合材料力学性能的影响

研究了不同硫化体系对炭黑填充天然橡胶力学性能的影响。结果表明,以N-(氧化二亚乙基)-2-苯并噻唑次磺酰胺(NOBS)为主促进剂的四种硫化体系中,半有效硫化体系硫化的橡胶的综合性能最好。在以N-环己基-2-苯骈噻唑次磺酰胺(CBS)+2-硫醇基苯骈噻唑(M)为促进剂的四种硫化体系中,用普通硫化体系(CV)硫化得到的碳黑/天然橡胶的综合性能最优。本文还研究了不同硫化体系对炭黑/碳纳米管填充天然橡胶力学性能的影响,结果表明,普通硫化体系(CV)硫化得到的碳纳米管/碳黑/天然橡胶的综合性能最优。     

高反式-1,4-丁二烯-异戊二烯共聚橡胶的结构表征及其在轿车轮胎子口护胶中的应用研究

采用逐步等温结晶分级法对高反式-1,4-丁二烯-异戊二烯共聚橡胶(TBIR)进行分级并对各级份进行了结构与组成表征.结果表明,TBIR-20为丁二烯单元无规分布、异戊二烯嵌段形成结晶的共聚物,TBIR-40为含TPB嵌段、TPI嵌段的共聚物;TBIR应用于轮胎子口护胶,可使混炼胶结晶度、格林强度和硬度增大,硫化速度加快;含TBIR的共混硫化胶的其他性能保持不变,压缩温升显著降低,耐磨耗性能和耐老化性能明显提高;DMA结果表明NR与TBIR的相容性优于BR,TEM结果表明并用TBIR后硫化胶中炭黑分散性更好.在轿车子午线轮胎子口护胶中应用20份左右的TBIR,其他力学性能保持在较高水平的同时,耐磨性、耐曲挠和耐老化性能显著提高,压缩温升明显降低.     

天然橡胶/稀土顺丁橡胶/反式丁戊橡胶并用高性能缺气保用轮胎胎侧支撑胶的结构与性能

研究了三种丁二烯结构单元含量和门尼粘度不同的反式丁戊橡胶(TBIR)改性天然橡胶/稀土顺丁橡胶(NR/Nd-BR)并用高性能缺气保用轮胎胎侧支撑胶的结构与性能.结果 表明,相比NR/Nd-BR(50/50)并用混炼胶,NR/Nd-BR/TBIR(45/45/10)并用混炼胶的Payne效应明显降低,填料网络结构明显削弱...     

Synergistic effect by high specific surface area carbon black as secondary filler in silica reinforced natural rubber tire tread compounds

The partial replacement of silica by high specific surface area and high structure Carbon Black (CB) N134 as secondary filler, keeping the same total filler content at 55 phr, shows a clear synergistic effect on overall performance. At low content of CB, i.e. in the range of 0–36 wt% of CB relative to total filler amount, the Payne effect and tan delta at both 0 °C and 60 °C change marginally, but thereafter gradually increase. Cure times are shortened in the presence of CB, facilitating an increase of productivity. Bound rubber content and mechanical properties show an optimum at 18 wt% of CB relative to total filler amount or at a ratio of silica/CB 45/10 phr. With regard to tire performance as indicated by the laboratory test results, the abrasion resistance, wet grip and ice traction can therefore be enhanced while maintaining the tire rolling resistance at the optimum level for this silica/CB ratio.     

Effect of nanocrystalline cellulose on the curing characteristics and aging resistance properties of carbon black reinforced natural rubber

This work focused on the effect of nanocrystalline cellulose (NCC) on the curing characteristics, aging resistance and thermal stability of natural rubber (NR) reinforced with carbon black (CB). Sharing the same fillers loading of 45 parts per hundred rubber (phr), NR/NCC/CB composites with different NCC/CB ratios (i.e. 0/45, 5/40, 10/35, 15/30, 20/25 phr) were prepared and analyzed. Resorcinol and hexamethylene tetramine (RH), acting as the modifier in NR/NCC interface, was also discussed for its influence. The result showed that an relatively higher ratio of NCC/CB led to a lower torque, a shorter cure time (T ₉₀), a slightly longer scorch time (T ₁₀) and a bigger vulcanization rate constant (K). This tendency suggested that the existence of NCC accelerated the vulcanization process. Additionally, modified by RH, NR/NCC/CB compounds exhibited a short T ₁₀ and a elevated torque. And a moderate RH content would lower the E _a of vulcanization. A 10 phr substitute of CB by NCC can help to improve aging resistance in terms of mechanical properties. In a high temperature aging condition, composites with 10 phr NCC also performed the highest storage modulus (G′) among composites tested. A moderate NCC content contributed to the best retention of G′ after high temperature aging, so did the incorporation of RH. With the partial replacement of CB by NCC, the temperature of 5% weight-lose had a slight drop and the apparent crosslink density showed a decrease. Thanks to the interaction of RH with both NR and NCC, composites showed an improvement in apparent crosslink density after modified by RH.     

Influence of Carbon Black and Silica Filler on the Rheological and Mechanical Properties of Natural Rubber Compound

Rubber compounds are reinforced with fillers such as carbon black and silica. In general, filled rubber compounds shows smooth rheological behavior and mechanical properties. Variation in rheological behavior and mechanical properties was studied in terms of the filler composition using natural rubber compounds filled with both carbon black and silica CB/Si = 0/60, 20/40, 30/30, 40/20 and 60/0 phr (parts per hundred rubber is parts of any non-rubbery material per hundred parts of raw gum elastomer (rubbery material)). The rheological behaviour can be showed in measurement of Mooney viscosity and cure time. The Mooney viscosity of rubber compounds increase with the increasing the carbon black in the compounds. The compound filled with CB/Si of 30/30 and 60/0 showed abnormal rheological behaviour in which the cure time decreased suddenly and the increased at certain ratio during the measurement. The mechanical properties such as hardness, abrasion resistance and tensile stress at 300% elongation were studied. In the hardness and abrasion resistance measurement, the higher ratio CB/Si decrease contribution of silica, which resulting smaller of hardness value. Ratio CB/Si 40/20 gives an optimum filler blended. It is also clearly understood that higher abrasion resistance mainly due to the lower hardness value under the same condition. The tensile stress at 300% elongation of rubber compound increased with the increasing carbon black filler.     

EFFECT OF INCORPORATING STARCH/SILICA COMPOUND FILLERS INTO UNCURED SSBR ON ITS DYNAMIC RHEOLOGICAL PROPERTIES

The dynamic rheological properties of a composite composed of solution-polymerized styrene butadiene rubber (SSBR) filled with starch/silica (SiO_2) compound fillers were studied by means of temperature,frequency and strain sweeps, respectively,and the influence of the starch content in the compound fillers (SCCF) on the rheological behaviors was discussed.It is found from frequency sweeps that a maximum of loss tangent (tanδ) appears at 20 rad/s,which is independent of SCCF.G' of the composites decrease...     

胶乳接枝插层法天然橡胶/蒙脱土/聚丙烯酸丁酯纳米复合材料结构与性能的研究

采用胶乳接枝插层法,引入单体,制备了天然橡胶蒙脱土聚丙烯酸丁酯纳米复合材料.X射线衍射(XRD)和透射电镜(TEM)结果表明,在单体丙烯酸丁酯(BA)的作用下,改性蒙脱土片层被进一步撑大,并在橡胶基体中以纳米级分散;动态粘弹谱(DMA)测定结果显示,该体系的玻璃化温度有所提高,且60℃时具有较低的tanδ值,说明具有较小的滚动阻力;物理机械性能测试表明该方法有效地实现了对天然橡胶的补强.     

Optical and mechanical properties of polyurethane/surface-modified nanocrystalline cellulose composites

in order to improve the optical and mechanical performances of waterborne polyurethane （WPU）, nanocrystalline cellulose （NCC）/WPU composites were synthesized in this study. NCC （prepared by acid hydrolysis of cotton fiber） was modified by （3-aminopropyl）triethoxysilane （APTES） to enhance its compatibility with WPU, and the surface-modified NCC was characterized by grafting ratio, crystallinity and contact angle （CA）. NCC/WPU composites were examined by scanning electron microscopy （SEM）, X-ray powder diffraction （XRD） and thermogravimetric analysis （TG）. The anti-yellowing property, specular gloss, pencil hardness, and abrasion resistance of NCC/WPU composites were investigated by the methods of Chinese National Standards GB/T 23999-2009, GB/T 9754-2007, GB/T 6739-2006 and GB/T 1768-2006, respectively. The results showed that the grafting ratio of NCC modified by 6% APTES was 36.01% and the crystallinity of modified NCC was decreased with the enhancement of APTES. CA of the modified NCC was decreased by 28.8% and the nanoparticles were homogeneously dispersed in the WPU matrix. The XRD patterns of the NCC/WPU composites were relatively steady, while the thermal stability of the composites was enhanced by 6.7% with 1.0 wt% modified NCC. Modified NCC affected the specular gloss of NCC/WPU composites more obviously than the anti-yellowing property. The pencil hardness of NCC/WPU composites was increased from 2H to 4H by addition of NCC and the abrasion resistance of the composites was enhanced significantly. In general, NCC/WPU composites showed significant improvements in the optical and mechanical performances.     

非交联组份对端乙烯基聚环氧丙烷/聚苯乙烯网状共聚物粘弹性的影响

本文描述了端乙烯基聚环氧丙烷/聚苯乙烯网状共聚物的合成及表征。研究了非交联组份对共聚物的玻璃化转变温度T_g,贮能模量E'、耗能模量E'和阻尼系数tanδ等动态力学性能的影响,计算了试样的粘弹性参数。结果表明,非交联组份对交联网有明显塑化作用,使其T_g降低,自由体积分数和阻尼系数增大。     

微波处理和溶胶凝胶法共同改性废胶粉及其与天然橡胶复合材料性能的研究

采用微波处理打断废胶粉(WRP)的三维网状结构用来提高WRP在有机溶剂中的溶胀性,然后采用溶胶凝胶法,将微波改性后的WRP浸入正硅酸乙酯中,通过水解反应和缩合反应,在WRP表面原位生成SiO2网络,从而制得改性废胶粉(MWRP).将制得MWRP与天然橡胶(NR)共混,制备了NR/MWRP复合材料,研究了NR/MWRP复合材料的性能.通过热重分析仪、差示扫描量热仪和力学分析表明微波处理最佳时间是20 s.由于微波处理提高了NR与WRP的相容性,原位生成的SiO2粒子起到了补强作用,所以所制备的NR/MWRP复合材料拥有较好的力学性能;随着Si69的加入,抑制了SiO2粒子聚集,提高了SiO2粒子的分散性,从而进一步提高复合材料的力学性能并降低复合材料的Payne效应;在进行频率扫描时,硫化胶的储存模量随频率的增大而增大;硫化胶的温度扫描结果表明,随着温度的升高,复合材料中SiO2粒子聚集程度加剧并且复合材料出现老化的现象.为了提高复合材料的耐老化性能,N,N-间苯撑双马来酰亚胺(BMI)作为一种防老剂加入复合材料中,BMI利用Diels-Aider反应补偿橡胶在老化过程中所损失的交联键并提高NR与WRP的界面相容性,从而提高复合材料的耐老化性能.     

Silica dispersion and properties of silica filled ESBR/BR/NR ternary blend composites by applying wet masterbatch technology

Silica is used as a reinforcing filler in the rubber product such as a tire. When silica contents increased in the composite, deterioration of the processability and silica dispersion in silica-rubber composites cannot be overcome only by adding a silane coupling agent. Therefore, silica wet-masterbatch (WMB) technology is considered for manufacturing highly silica filled composites. Herein, we investigated silica dispersion, cure behavior, mechanical properties, abrasion characteristics, and viscoelastic properties of 3 types of WMB blend composites. Up to 82% improvement in silica dispersion was determined by the Payne effect and confirmed by atomic-force microscopy. The tensile strength and elongation at break increased and tan δ at 60 °C decreased by improving silica dispersion. The silica WMB is suitable for manufacturing highly silica filled composites.