半穿透型水膠的合成及作為水泥砂漿自養護劑之研究

張志成(Chih Cheng Chang)

指導教授 ： 許貫中

國立臺灣師範大學/理學院/化學系/碩士(2010年)

摘要

本篇論文主要是合成一半穿透式網狀(semi-IPN)水膠poly 2-(3-carboxy- propanamido) acetate/polyacrylamide (PPAA/PAM)，探討其作為混凝土自養護劑的可行性。實驗上使用PPAA和acrylamide(AM)，以APS為起始劑、MBA為交聯劑聚合得到PPAA/PAM水膠。探討起始劑濃度、交聯劑濃度與PPAA相對於PAM重量比例對於PPAA/PAM在純水中吸水率的影響，以及水膠在鹽水和不同pH值與溫度下的吸水行為，並且藉由電子掃描顯微鏡觀測水膠吸水前後的孔洞大小。另外，將水膠加入砂漿中，探討水膠對於砂漿重量損失、內部濕度、抗壓強度與乾縮的影響。
研究結果顯示在適當反應條件下可成功的聚合得到PPAA/PAM水膠。合成的單體與水膠藉由NMR及FT-IR光譜來確認其結構。隨著APS濃度的增加，水膠在純水中的吸水率呈現先增後減的趨勢；隨著MBA濃度的增加，水膠的吸水率漸減；隨著PPAA含量的增加，水膠的吸水率漸增。當APS的莫耳濃度相對於AM單體的濃度為1.0 %、MBA的莫耳濃度為2.0 %、PPAA相對於PAM重量比例為1時所製得之水膠(代號P1115)在純水中的飽和吸水率達到426 g/g，在0.1M NaCl(aq)和0.1M CaCl2(aq)的飽和吸水率分別為69和66 g/g。添加0.2wt% P1115的水泥砂漿(M02)在28天的重量損失13.2g，低於未添加水膠的水泥砂漿(M00)重量損失(=14.3g)；M02在28天的抗壓強度為34.2 MPa，高於M00的抗壓強度(=31.9 MPa)；M1在28天的內部相對濕度為68.7%，高於M0的相對濕度(=64.7%)；M1在28天的乾縮量為0.189 mm，低於M0的乾縮量(=0.236 mm)。XRD與DSC的測試結果顯示添加P1115的水泥漿之水泥水化程度亦高於未添加水膠的水泥漿。

關鍵字

半穿透式水膠 ； 吸水率 ； 砂漿 ； 自養護劑 ； 重量損失

並列摘要

This thesis is to prepare a semi-IPN hydrogel, i.e., poly 2-(3-carboxy- propanamido) acetate/polyacrylamide (PPAA/PAM) as a potential self-curing agent for concrete. Experimentally, PPAA/PAM hydrogel was prepared by reacting PPAA and acrylamide using APS as an initiator, MBA as a crosslinking agent. The effects of APS concentration, MBA concentration, and PPAA/PAM ratio on the water absorbency of the hydrogel in deionized water were examined. The water absorption behavior of the hydrogel in salt solutions at different pH values and temperatures was also studied. The pore size of the hydrogel before and after water-absorption was observed and analyzed using a SEM. Furthermore, the hydrogel was added in mortars; the effects of hydrogel on the properties of mortars such as weight loss, humidity, compressive strength, and dry shrinkage were determined.
The results indicated PPAA/PAM hydrogel was prepared successfully; its structure was verified by the NMR and FT-IR spectra. Along with increasing APS concentration, the water absorbency of the hydrogel in deionized water increases initially, reaches a maximum, and then decreases afterward. The water absorbency decreases with increasing MBA concentration or PAM content monotonically. The saturated water absorbencies of P1115 hydrogel ( [APS]/[AM] =1%, [MBA]/[AM]=2%, and [PPAA]/[PAM]=1) are 426 g/g, 69 g/g, and 66 g/g in deionized water, 0.1M NaCl(aq) and 0.1M CaCl2(aq) respectively. The weight loss of mortars with 0.2% P1115 (M02) is 13.2g, which is lower than that (=14.3g) of mortars without any hydrogel present (M00). The compressive strength of M02 is 34.2 MPa, which is higher than that (=31.9 MPa) of M00. The relative humidity in M02 is 68.7%, which is higher than that (=64.7%) in M00. The dry shrinkage of M02 is 0.189 mm, which is lower than that (0.236 mm) of M00. Finally, incorporation of hydrogel could improve the degree of cement hydration in cement pastes, as examined from both XRD and DSC measurements.

並列關鍵字

semi-IPN hydrogel ； water absorbency ； mortar ； self-curing agent ； weight loss

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