兩種半穿透型水膠之製備以及作為水泥砂漿自養護劑

The Preparation and Application of two Semi-IPN Hydrogel as Self-Curing Agents for Cement Mortars

周宜婷

指導教授 ： 許貫中

國立臺灣師範大學/理學院/化學系/碩士(2011年)

摘要

本篇論文為製備兩種半穿透式網狀水膠(semi-IPN)︰polyaspartate/polyacrylamide (Pasp/PAM) and poly(2-(3-carboxypro pan- amido) acetate)/polyacrylamide/polyethylene glycol (PPAA/PAM/ PEG)。Pasp/PAM水膠係以Pasp與丙烯醯胺為反應物，Ammonium persulfate (APS) 為起始劑，N,N’ methylene bisacrylamide (MBA)為交聯劑，經由自由基聚合反應而得；PPAA/PAM/PEG水膠係以PPAA、PEG與丙烯醯胺為反應物，APS 為起始劑 MBA為交聯劑，經由自由基聚合反應而得。聚合得到的兩種水膠均經由量測分析其FTIR光譜確認。另外，量測兩種水膠在水溶液中的吸水率。
(一) Pasp/PAM水膠
探討不同單體配比、交聯劑和起始劑濃度，對於Pasp/PAM水膠在水溶液中吸水率的影響。將水膠加入水泥漿中，探討水膠含量對於水泥漿的水泥水化程度和凝結時間的影響；將水膠加入砂漿中，探討水膠含量對於砂漿重量損失、內部濕度、抗壓強度、長度變化的影響。
研究結果隨著PAM含量的增加水膠含量的吸水率漸減；隨著APS或MBA濃度的增加水膠含量的吸水率呈現先增加、達最大值後開始減少。當聚合時添加0.8 mol% APS, 0.5 mol% MBA, Pasp/PAM=1/1，所得的水膠有最大的吸水率，在純水、0.1M NaCl(aq)和0.1M CaCl2(aq)的飽和吸水率分別為159.7g/g, 39.2 g/g和32.2 g/g。
隨著水膠含量的增加，7-28天水泥漿體中的水泥水化程度先增加、達最大值後開始減少，水膠添加量為0.2wt%的水泥漿體中的水泥水化程度最高。另外，隨著水膠含量的增加，水泥漿體的初凝時間變長而終凝時間變短。
隨著水膠含量的增加，砂漿試體的重量損失、長度變化呈現先減少、達最小值後開始增加；內部濕度、抗壓強度則先增加、達最大值後開始減少。水膠添加量為0.2wt%的砂漿試體有最小的重量損失和長度變化，有最高的內部濕度和抗壓強度。隨著水膠含量的增加，水泥漿體的初凝時間變長而終凝時間變短。
水膠添加量為0.2wt%的28天砂漿試體的重量損失為13.03 g，為未添加水膠砂漿(14.46 g)的90.1%；抗壓強度為38.66 MPa，比未添加水膠砂漿(25.31 MPa)高；內部相對濕度為56.7 %，比未添加水膠砂漿(52 %)高；長度變化為為-0.19 mm，比未添加水膠砂漿(-0.210 mm)小。

(二) PPAA/PAM/PEG水膠
探討PEG含量對於PPAA/PAM/PEG水膠在水溶液中吸水率的影響。將0.2wt%水膠加入水泥漿中，探討PEG含量對於水泥漿的水泥水化程度和凝結時間的影響；將0.2 wt%水膠加入砂漿中，探討水膠含量對於砂漿重量損失、內部濕度、抗壓強度、長度變化的影響。
研究結果隨著PEG含量的增加水膠含量的吸水率漸減。當聚合時添加1.0 mol% APS, 0.2 mol% MBA, PPAA/PAM=1/1，所得的水膠，在純水、0.1M NaCl(aq)和0.1M CaCl2(aq)的飽和吸水率分別為410.8g/g, 65 g/g和63 g/g。而PEG若接入水膠後其吸水率會下降，例如聚合時添加1.0 mol% APS, 0.2 mol% MBA, PPAA/PAM/PEG=1/1/0.5，所得的水膠，在純水、0.1M NaCl(aq)和0.1M CaCl2(aq)的飽和吸水率分別為189.4 g/g, 32.3 g/g和29.8 g/g。
隨著PEG含量的增加，3-28天添加0.2 wt% 水膠的水泥漿體中的水泥水化程度先增加、達最大值後開始減少，PEG含量為20 wt%的水泥漿體(水膠添加量為0.2wt%)中的水泥水化程度最高。另外，隨著PEG含量的增加，水泥漿體的初凝時間變長而終凝時間則改變不大。
隨著PEG含量的增加，添加0.2 wt% 水膠的砂漿試體的重量損失、長度變化呈現先減少、達最小值後開始增加；內部濕度、抗壓強度則先增加、達最大值後開始減少。PEG添加量為20 wt%的砂漿試體(PPAA/PAM/PEG(=1/1/0.2)水膠添加量為0.2wt%)有最小的重量損失和長度變化，有最高的內部濕度和抗壓強度。

關鍵字

半穿透式水膠 ； 製備 ； 反應物比例 ； 吸水率 ； 水泥漿 ； 水化程度 ； 砂漿 ； 重量損失 ； 溼度 ； 抗壓強度 ； 長度變化

並列摘要

This thesis has prepared two semi-IPN hydrogels, i.e., polyaspartate/polyacrylamide (Pasp/PAM) and poly(2-(3-carboxypropanamido) acetate)/polyacrylamide/polyethylene glycol (PPAA/PAM/PEG). Pasp/PAM hydrogel was prepared from polyaspartate and acrylamide through free radical polymerization. PPAA/PAM/PEG hydrogel was prepared from poly(2-(3- carboxypropanamido)acetate), polyethylene glycol, and acrylamide through free radical polymerization. Ammonium persulfate (APS) and N,N’ methylene bisacrylamide (MBA) were used as an initiator and a crosslinking agent, respectively. The chemical structures of both hydrogels were verified by FTIR spectroscopy. The water absorbency of these hydrogels in aqueous solutions was measured.
1. Pasp/PAM hydrogel:
The effect of reactant ratio, APS and MBA content on the water absorbency of Pasp/PAM hydrogel was studied. The hydrogel was then added in cement pastes and mortars. The effects of the hydrogels on the properties of cementitious materials were determined and discussed.
The result indicates that the water absorbency of Pasp/PAM hydrogel increased with decreasing PAM content. Increase of either APS or MBA content increased the water absorbency initially, reached a maximum value, and decreased afterwards. The hydrogel showed the highest water absency when it was prepared with Pasp/PAM=1/1, using 0.8 mol% APS and 0.5 mol% MBA. The saturated water absorbency were 159.7 g/g, 39.2 g/g, and 32.2 g/g, in pure water, 0.1M NaCl(aq), and 0.1 M CaCl2(aq), respectively.
At 7 and 28 days, the degree of cement hydration increased with hydrogel content first, reached a maximum value, and decreased afterwards. The cement pastes with 0.2 wt% hydrogel showed the highest degree of cement hydration. Along with increasing hydrogel content, the initial setting time increased, but the final setting time decreased.
Increase of hydrogel content decreased the weight loss and length change of mortars, reached minimum values, and increased subsequently. Increase of hydrogel content increased the relative humidity inside mortars and improved the compressive strength, reached maximum values, and decreased subsequently. The mortars with 0.2 wt% hydrogel showed the lowest weight loss and length change, and the highest relative humidity and compressive strength.
2. PPAA/PAM/PEG hydrogel:
The effect of PEG content on the water absorbency of PPAA/PAM/PEG hydrogel was studied. The hydrogel was then added in cement pastes and mortars. The effects of the PEG content on the properties of cementitious materials with 0.2 wt% hydrogel were determined and discussed.
The result indicates that the water absorbency of PPAA/PAM/PEG hydrogel decreased with increasing PEG content. The hydrogel showed the highest water absency when it was prepared with PPAA/PAM =1/1, using 1.0 mol% APS and 0.2 mol% MBA. The saturated water absorbency were 410.8 g/g, 65 g/g, and 63 g/g, in pure water, 0.1M NaCl(aq), and 0.1 M CaCl2(aq), respectively. The hydrogel showed the highest water absency when it was prepared with PPAA/PAM/PEG =1/1/0.5, using 1.0 mol% APS and 0.2 mol% MBA. The saturated water absorbency were 189.4 g/g, 32.3 g/g, and 29.8 g/g, in pure water, 0.1M NaCl(aq), and 0.1 M CaCl2(aq), respectively.
At 3-28 days, the degree of cement hydration with 0.2 wt% hydrogel increased with PEG content first, reached a maximum value, and decreased afterwards. The cement pastes with 0.2 wt% hydrogel containing 20 wt% PEG showed the highest degree of cement hydration. Along with increasing PEG content, the initial setting time increased, but the final setting time did not change significantly.
Increase of PEG content decreased the weight loss and length change of mortars with 0.2. wt% hydrogel, reached minimum values, and increased subsequently. Increase of hydrogel content increased the relative humidity inside mortars and improved the compressive strength, reached maximum values, and decreased subsequently. The mortars with 0.2 wt% hydrogel containing 20 wt% PEG (PPAA/PAM/PEG=5/5/1) showed the lowest weight loss and length change, and the highest relative humidity compressive strength.

並列關鍵字

semi-IPN hydrogel ； preparation ； reactant ratio ； water absorbency ； cement paste ； degree of cement hydration ； mortar ； weight loss ； humidity compressive strength ； length change

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