- 學位論文
高性能綠色輪胎的非平衡動態混煉過程與分散劑反應性研究: 超小角X光分析
Non-Equilibrium Dynamic Mixing Process and Dispersant Reactions for High Efficiency Green Tires: USAXS Analysis
摘要
我利用正新輪胎工廠內的試驗級橡膠萬馬力機(banbury)，混煉工業級配方的輪胎胎面橡膠，並取得密煉機的混煉相關數據，例如混合過程中混煉機施加的扭矩(torque)，混煉槽內的溫度變化等資訊，並分析混煉過程中胎面膠內填充物顆粒型態變化對輪胎性質的影響。本實驗使用高親水性的二氧化矽作為補強材料與高疏水性橡膠混合以提升橡膠物理性質，由於二氧化矽表面的-OH基團會使二氧化矽互相聚集，所以必須添加TESPT (bis[3-(triethoxysilyl)propyl] tetrasulfide)，俗稱Si69的矽烷偶聯劑作為分散劑，在混煉的過程中與二氧化矽表面發生化學反應，降低二氧化矽表面極性。矽烷偶連劑是由有機物與矽構成的化合物，其分子具有分別與二氧化矽顆粒以及橡膠產生化學鍵結的官能基團，能提高二氧化矽顆粒在橡膠內的分散性，所以我想了解Si69與二氧化矽顆粒的反應性對胎面膠機械性質的影響，因此我將未交聯及交聯後橡膠拿去做熱裂解氣相色譜-質譜儀分析，藉由測得胎面膠中未與二氧化矽顆粒表面反應的Si69相對含量，讓我們了解橡膠中矽烷化反應(silanization)的程度，加上從動態機械性質分析(變溫DMA以及Payne effect拉伸試驗)中所測到的動態性質數據，我們就能藉由調控Si69的添加量，生產出不同性能需求的橡膠產品，搭配X光小角散射(SAXS)和原子力顯微鏡(AFM)等技術，我們便得以從結構的觀點分析Si69的添加量對橡膠樣品物理性質的影響。 我到新竹國家同步輻射中心(NSRRC)TLS23A1以及TPS25A1等工作站，使用同步加速環產生的X光穿過橡膠樣品，利用二氧化矽顆粒對X光散射的能力，來獲得關於二氧化矽顆粒在胎面膠內分散的結構資訊，同時我們改變胎面膠的製造程序以及成分，來調控二氧化矽在橡膠的結構變化，幫助我們了解二氧化矽的製造程序與結構對橡膠性能的影響。
並列摘要
In this study, we investigate the mixing effect of rubber/filler systems by using a pilot banbury rubber mixer at Cheng Shin Rubber Ind. Co. ltd to produce industrial-grade tire tread compounds, obtain the data regarding to the processing parameters, such as the torque applied by the mixer and temperature profiles in the mixing tank, and analyze the structural changes in the tread compounds during the various formulation adjustments and mixing processes. Highly hydrophilic silica nanoparticles were used in this experiment as a reinforcing material in highly hydrophobic rubbers to improve the physical properties of the tire tread compounds. Since the -OH group on the surface of the silica causes the silica particles to aggregate with each other to form hierarchical structures, TESPT (bis [3-(triethoxysilyl)propyl] tetrasulfide), commonly known as Si69, acting as a dispersant was added in the compound so as to be chemically grafted onto the surface of silica nanoparticles during mixing process to reduce its surface polarity to improve silica dispersibility in rubbers, The coupling agent is composed of an organic substance and silicon, and has functional groups to bond to silica nanoparticles and rubber molecules separately to improve the dispersibility of silica in the compounds, My objective for the thesis was to understand the reaction of Si69 with silica nanoparticles and its optimum amount on the mechanical properties of tread compounds. By using pyrolysis gas chromatography/mass spectrometry, I was able to measure the relative amount of unreacted Si69 during the mixing process in the uncrosslinked and cross-linked compounds so that the degree of average silanization of Si69 on silica nanoparticles can be obtained. The amount of Si69 added in the compounds was studied and its effect on the dynamic mechanical property (tangent delta curve and Payne effect profile) as measured by dynamic mechanical analysis. The correlation between process/structure/property (rolling resistance, wet traction, and stiffness) of the tread compounds was investigated as a function of Si69 amount. In particular, ultra-small angle x-ray scattering (USAXS) technique, conducted at the TLS23A1 and TPS25A1 end-stations of the National Synchrotron Radiation Center (NSRRC) in Hsinchu, Taiwan as used to analyze the hierarchical structure of silica nanoparticles and to correlate the structure with the measured property. Based on a fractal model developed by Hashimoto, I created a corresponding software program to simulate USAXS spectrum to understand the internal structures built up by the fillers in the tire tread compounds.