兩性分散劑的合成以及對於氧化石墨烯砂漿性質的影響

Abstract

本論文研究目的在於合成一種兩性離子型磺酸系分散劑來改善氧化石墨烯在水泥基材料中的分散性並提升漿體的機械性質。使用甲基丙烯酸二甲基丙基磺酸胺乙酯 (N-(3-sulfopropyl)-N- methacroyloxyethyl-N,N-dimethyl-ammonium betaine)與丙烯醯胺(Acrylamide)為單體，起始劑為Benzoyl peroxide，經由自由基聚合反應得到分散劑Poly(sulfobetaine-co-acryl amide)(PSA)，化學結構經由FT-IR和1H-NMR光譜鑑定，以GPC測量聚合物的分子量。石墨烯則是經由Hummers法氧化成氧化石墨烯，化學結構再經由FT-IR、RAMAN、SEM觀察其結構變化。 經由沉降體積、粒徑分布、界達電位和流變性質實驗結果顯示，添加PSA42 (Mw = 5.4×105)在氧化石墨烯人工孔隙溶液中的分散效果優於其他分子量之聚合物，因PSA42於氧化石墨烯表面有較小的粒徑、較高的界達電位、較低的黏度以及在水泥砂漿中添加10wt% PSA42和0.05 wt% GOA的28天抗壓強度為32.5MPa、抗彎強度為7.1MPa，與控制組相比能分別提升84%、97%；最後經由XRD和DSC實驗則觀察到在水泥漿中添加GO能有效加速和增加前期水化產物的形成。

This research focused on the enhancing the dispersibility of graphene oxide in the cement-based materials, and improving the mechanical properties. First, we synthesized a amphoteric dispersant, Poly(sulfobetaine -co-acrylamide) (PSA)) is synthesized by N-(3-sulfopropyl)-N-methacroyloxyethyl-N,N-dimethyl-ammonium betaine(SB) and acrylamide as monomer, benzoyl peroxide as initiator. FT-IR, 1H-NMR was used to identify the functional groups of the dispersant. Molecular weight of the polymer was measured by GPC. Then, we used Hummers Method to oxidize graphene, and FT-IR, RAMAN, SEM to observe the change of chemical structure. The experimental results of sedimentation volume, particle size distribution, zeta potential and rheological properties showed that the dispersion effect of PSA42 (Mw = 5.4×105) in the graphene oxide artificial pore solution is better than other polymers, because PSA42 causes small particle size, high zeta potential, low viscosity. The results of compressive and flexural strength test of 28-day cement mortar with 10 wt% PSA42 and 0.05 wt% GOA were 32.5MPa and 7.1MPa respectively, which increased by 84% and 91% respectively compared with the control sample. Finally, it was observed through XRD and DSC experiments that the addition of GO to the cement paste can effectively accelerate and increase the early formation of hydration products.