【作者】 周明；

【导师】 郑强； 宋义虎；

【作者基本信息】 浙江大学 ， 材料科学与工程， 2006， 硕士

【摘要】 通常绿色轮胎胎面胶使用SiO₂作为补强材料,而SiO₂粒子不易在橡胶中分散,导致胶料性能变差。除混炼工艺外,偶联剂的应用被认为是改善SiO₂分散状态的重要手段。双官能团硅烷偶联剂不仅能提高其与橡胶相容性,还可与橡胶发生反应,导致SiO₂与橡胶的结合力增大,使SiO₂分散更加均匀。 本论文以γ-巯丙基三乙氧基硅烷与己酰氯为单体,在N₂保护与低温下合成新型偶联剂3-己酰基硫代-1-丙基三乙氧基硅烷（HXT）。将HXT与双-（3-乙氧基硅基丙基）-二硫化物（TESPD）分别添加到溶液聚合丁苯橡胶（SSBR）/SiO₂混炼胶体系中,采用流变学方法表征复合体系的动态粘弹行为。结果表明,HXT可改善填料和基体的相互作用,有效阻止SiO₂粒子在加工过程中的团聚。与TESPD相比,含HXT体系具有较高“Payne效应”临界应变值（γ_c）。 研究了高填充补强SSBR混炼胶的动态流变特性。分别考察了在两个混炼温度（120℃、160℃）下添加三种不同偶联剂(双-（3-乙氧基硅基丙基）-四硫化物、双-（3-乙氧基硅基丙基）-二硫化物（TESPD、3-辛酰基硫代-1-丙基三乙氧基硅烷）对SiO₂粒子表面改性的效果。结果表明,较低混炼温度不利于偶联剂对SiO₂粒子的表面改性,在较高混炼温度下,偶联剂TESPT、PESPD、NXT均对SiO₂粒子表面有显著的改性效果,但同时引起混炼胶不同程度的焦烧,其中以TESPT最明显。随SiO₂粒子表面改性程度的提高,出现“Payne效应”的临界应变（γ_c）值以及低频率（ω）区域动态储能模量（G′）与ω的对数关系logG′～logaω曲线的斜率值均增大,反映出偶联剂对SiO₂与SSBR相互作用的促进以及SiO₂粒子分散的改善。 考察了填料含量与偶联剂结构对SSBR/SiO₂动态流变行为的影响。不含偶联剂体系出现SiO₂聚集体。在G′～γ系图中出现了“Payne效应"以及高抠域的G′与G″峰值;同时,低ω区域出现明显的G′平台。偶联剂的加入,促进了SiO₂在体系中的分散,增强了体系中填料的网络结构,使体系的模量降低,G′的线性粘弹区域（Linear Viscoelastic Range,LVR）显著增大;而动态损耗模量（G″）～γ曲线出现G″极大值,高γ区域的G′与G″峰值消失,同时低γ区域力学损耗正切值（tanδ）减小。更多还原

【Abstract】 "Green Tire" with saving benzine and reducing exhaust emission is believed to be a promising direction of tire industry. Precipitated silica （SiO₂） is an especially useful additive to "Green Tire", for reducing rolling resistance, and heat build-up. Howerver, there exist a lot of hydrophilic silanol groups on surfaces of silica, leading to their compatibility with hydrophobic rubbers. Silane having bifunctional group facilitate interaction between SiO₂ and rubber which induce more even dispersion due to their compatibilities enhanced.A minimum dump temperature of 130 ℃ is required to ensure silica and silane to react to desired extents. However, at high temperatures, coupling agent such as bis-（3-triethoxysilylpropyl）-tetraslufide （TESPT） either starts to react with rubber or donates sulfur, which leads to scorch. Therefore, requirement of investigation on new silane with lower reactivity during mixing has been fully recognised.3-Hexanoylthio-1-propyltriethoxysilane （HXT） was synthesized from reaction of 3-triethoxysiyl-1-propanethiol and hexanoyl chloride. HXT or bis-（triethoxysilylp-ropyl）-disulfide （TESPD） as coupling agent were incorporated into polymerized styrene-butadiene rubber （SSBR）/silica （SiO₂） compounds. Moreover, dynamic rheological behaviors of the compounds were investigated by using an advanced rheomitric expended system （ARES）. It is found that incorporation of silane coupling agent into SSBR/SiO₂ compounds improves the elastic properties and weaken the "Payne effect" due to the surface modification of SiO₂ particles and the improved dispersion of the particles in the SSBR matrix.Effect of silane coupling agent on the dynamic rheological behaviors for unvulcanized SSBR/ SiO₂ compounds was also investigated. It is found that the molecular structure of silane coupling agent significantly influences dynamic storage modulus （G’） in the temperature region from 100 to 180 ℃ and also the strain （γ） as well as frequency （ω） dependence of G’ at 100 ℃. The critical strains （γ_c） from linearto nonlinear region are 1.00 %, 0.36 % and 0.57 %, and the slopes of plotting logG’ vs.logtu in the low co region （terminal region） are 0.14,0.17 and 0.20, for the compounds containing TESPT, TESPD and NXT, respectively. It is suggested that the increase of both yc value and the slopes of those plots are responsible for surface-modification of S1O2 particles and enhancement of interaction between the particle and SSBR.The influence of filler loadings and silane on the dynamic rheological behaviors for unvulcanized SSBR/SiC>2 compounds was investigated. It is found that incorporation of 30 phr SiO2 without silane induces a significant change of the dynamic rheological behaviors for SSBR/SiC>2 compounds because of the strong interactions among SiO2 particales. Meanwhile, it is noted that "Panye effect" and peaks in the high y regions of G’ and G" can be observed obviously for SSBR/SiO2 compounds. On the other hands, the influence of different filler loadings with silane on the dynamic rheological behaviors for SSBR/SiC>2 compounds was also investigated. It is found that yc of SSBR/SiC>2 compounds with silane increase and G’ and G" peaks in the high y region disappear. The reason for these is resulting from the surface-modification of SiC>2 particles and enhanced interaction between SiC>2 and SSBR.Effect of silane coupling agent on the mechanical properties for vulcanized SSBR/SiC>2 compounds was investigated by a universal testing and dynamic mechanical analysis （DMA）. Addition of silica alone leads to significant change in the tensile properties. A remarkable increases in the moduli are observed for SSBR filled with SiO2 containing TESPT. The 100% and 300% moduli of SSBR/SiO2 with silane increase significanty. The ratio of 100% to 300% moduli is reported as an alternative measurement of coupling efficiency. The the highest ratio appears in the vulcanites containing NXT, indicating that the coupling efficiency of NXT is the best. It is also found that the traction properties of SSBR/SiC^ with different silane on water and snow are almost the same and vulcanites containing NXT has the lowest rolling resistance and heat build-up.Keywords: Solution-polymerized styrene butadiene rubber（SSBR）, Silica（SiO2）, Silane coupling agent, Surface-modification, Dynamic rheological behavior.更多还原