利用有機矽烷耦合劑及高分散性二氧化矽強化綠色輪胎之動態機械性質

Abstract

本研究中使用萬馬力混煉機(banbury)，將橡膠材料與高分散性二氧化矽(highly-dispersive silica)進行混合，用以強化橡膠之機械性質並作為製造輪胎之胎面(tire tread)配方。 由於二氧化矽與橡膠的親疏水性不同，因此必須使用矽烷耦合劑(silane)以降低二氧化矽顆粒表面的極性並使其在親油性橡膠中均勻分散。 在本研究將改變這些工業級的配方(二氧化矽與矽烷耦合劑)來使胎面膠達到理想的滾動阻力、濕地抓地力、剛性之三重性能。 研究內容包含-改變混煉配方: 一、添加不同比表面積(specific surface area)的二氧化矽顆粒。 本研究利用Evonik公司製造之SilicaB與SilicaA兩種二氧化矽顆粒，研究填充物(filler)大小形狀的不同對於胎面膠以及矽烷耦合劑使用量之影響。 二、使用不同矽烷耦合劑:A.雙邊乙氧基團官能基的TESPT(俗稱SilaneA)與B.一邊乙氧基團一邊硫醇基(thiol)的SilaneB，我也研究不同矽烷耦合劑對二氧化矽顆粒的分散效果之影響。 實驗分析分為三大部分: silane反應量分析、動態機械性質量測、二氧化矽結構分析。 Silane反應量分析由熱裂解氣相質譜儀(Pyrolysis GC-MS)分析未與二氧化矽顆粒表面反應所剩餘的silane相對含量，了解此配方在二氧化矽顆粒表面之矽烷化(silanization)程度。 動態機械性質量測胎面膠的潘恩效應(Payne effect)以及濕抓、滾阻、剛性等物理性質。 二氧化矽顆粒之聚集狀態結構分析利用原子力顯微鏡(AFM)以及穿透式電子顯微鏡(TEM)切片觀察二氧化矽顆粒分布，以及使用國家同步輻射中心(NSRRC)之TPS25A1工作站，以同步加速環的X光穿透樣品，並以X光之散射(SAXS)分析二氧化矽顆粒在橡膠中所表現的結構變化。

In this study, we use a banbury mixer at CST Ind. Co. to mix rubbers with highly-dispersible silica to improve the mechanical properties of rubbers for uses as a tire tread. Due to the different hydrophilicity between silica and rubbers, silane coupling agent must be used to reduce the polarity of silicas and make them evenly dispersed in the rubber system. I modify the tread formulas to achieve a better rolling resistance, wet grip, and stiffness. The compound formula is modified according to the following principles: 1. Silica is changed by using the fillers with different specific surface area: SilicaB and SilicaA silicas manufactured by Evonik. The effect of different silica addition on the morphology of the fillers and the resulting tread property as a function of silane coupling agent loading is studied. 2. The effect of using different silane coupling agents, TESPT (commonly known as SilaneA) with bilateral ethoxy groups and SilaneB with only one ethoxy group and one thiol (SH) group at the other end is investigated as a function of their addition concentrations. The analysis of the nanocomposites is mainly divided into three parts: the analysis for the extent of silane reaction during banbury mixing, the measurement of dynamic mechanical property, the analysis of silica hierarchical structure and their structure- property relation. The extent of silane reaction is based using pyrolysis GC-MS technique to analyze the relative amount of unreacted silane with inorganic filler left in the compounds to understand the degree of silanization coverage on silica surface. The dynamic mechanical property measures the Payne effect which is related to the effect of filler-filler interaction. In addition tan (delta) and elastic modulus at different temperature of their dynamic property can be related to the physical properties of the tire tread compounds such as wet grip, rolling resistance, and stiffness. The structural analysis of silica is based on the complimentary techniques of atomic force microscopy, transmission electron microscopy and small angle X-ray scattering (SAXS) located at the TPS25A1 workstation of the NSRRC to analyze their hierarchical structural transformation of different silica types, loadings, and different silane surface modifications in the rubber system.