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Synthesis and characterization of chitosan-g-poly(acrylic acid)/attapulgite superabsorbent composites Junping Zhang a,b, Qin Wang a,b, Aiqin Wang a,* Carbohydrate Polymers 68 (2007) 367–374 指導教授：林鴻儒 博士 姓名：徐楓茜 日期：98.08.14 Outline • • • • • Introduction Materials Experimental Results and discussion Conclusions Introduction • 親水性的網狀高分子，可把水份鎖在裡面，不易流失。像 傳統的吸水性材料如海綿，棉和紙漿等。這些高吸水性材 料廣泛的應用在衛生產品，園藝，藥物釋放，煤炭脫水， 然而這些材料都容易降解，對環境有影響。 • 因此Kiatkamjornwong等人利用親水性單體乙烯基接枝在天 然高分子澱粉及Chitosan側鏈上的-NH2及-OH，使其水膠 具有吸水之性質。 • 現今Chitosan廣泛的應用於生醫材料，且具有較好的生物 相容性。 • 因此利用高吸水性材料丙烯酸接枝Chitosan，不僅可以改 善生物降解的問題，且材料也具有吸水的特點。 Introduction • 近年來，Clay常應用於與吸水性材料做結合，來改善其膨 潤性質與降低成本並可加強水膠之強度。 Material • • • • • Acrylic acid (AA) ammonium persulfate (APS) N,N’-methylenebisacrylamide (MBA) Chitosan (CTS) Attapulgite (APT) Experimental - different MW 2 g CTS 40 ml distilled water 30% H2O2(0.3, 1.0, 3.7, 9.4ml) Stirred and kept at 50℃, 2h Suspension Average molecular weight of CTS was determined by viscometry measurement Filtrated Solid (washed) Solid Washed with distilled water to pH=7 Solid Dried under vacuum at 50℃ Preparation of CTS-g-PAA/APT 1% acetic acid solution 30ml CTS In the 250 ml four-neck flask, equipped with a mechanical stirrer, a reflux condenser, a funnel and a nitrogen line Purged with nitrogen for 30 min to remove oxygen and heated to 60 ℃ 0.10 g APS 10 min 3.55 g AA MBA and APT The water bath, kept 60℃, 3h Use 40-80 mesh milled Spread on a dish to dry overnight at room temperature Use filter paper wiping off excessive dewatering agents Transferred 1M NaOH aqueous solution to be neutralized to pH=7, dried in oven or dewatering agents, methanol, ethanol and acetone Results and discussion COOH COO- C-H C-H OH C3-OH C=O -NH2 -NHCO C-H C6-OH COOCOO- Si-OH Fig. 2. IR spectra of (a) APT, (b) uncrosslinked CTS-g-PAA/APT, (c) CTS, (d) CTS-g-PAA and (e) CTS-g-PAA/APT. Weight ratio of AA to CTS is 7.2; average molecular weight of CTS is 22.9*104; MBA content is 2.94 wt%; APT content is 10 wt%; dewatered with methanol. 381.7℃ 578.4℃ 604.3℃ Fig. 3. TGA curves of CTS-g-PAA and CTS-g-PAA/APT. Weight ratio of AA to CTS is 7.2; average molecular weight of CTS is 22.9*104; MBA content is 2.94 wt%; APT content is 10 wt%; dewatered with methanol. Fig. 4. SEM micrographs of (a) APT, (b) CTS-g-PAA and (c) CTS-g-PAA/APT superabsorbent composite. Weight ratio of AA to CTS is 7.2; average molecular weight of CTS is 22.9*104; MBA content is 2.94 wt%; APT content is 10 wt%; dewatered with methanol. Fig. 5. Variation of water absorbency for the CTS-g-PAA/APT superabsorbent with average molecular weight of CTS. Weight ratio of AA to CTS is 7.2; MBA content is 2.94 wt%; APT content is 10 wt%; dewatered with methanol. Fig. 6. Variation of water absorbency for the CTS-g-PAA/APT superabsorbent composite with MBA content. Weight ratio of AA to CTS is 7.2; average molecular weight of CTS is 22.9*104; APT content is 10 wt%; dewatered with methanol. Fig. 7. Variation of water absorbency for the CTS-g-PAA/APT superabsorbent composite with weight ratio of AA to CTS. Average molecular weight of CTS is 22.9*104; MBA content is 2.94 wt%; APT content is 10 wt%; dewatered with methanol. Fig. 8. Variation of water absorbency for the CTS-g-PAA/APT superabsorbent composite with weight ratio of AA to CTS. Weight ratio of AA to CTS is 7.2; average molecular weight of CTS is 22.9*104; MBA content is 2.94 wt%; dewatered with methanol. Fig. 9. Variation of water absorbency for the CTS-g-PAA/APT superabsorbent composite with dewatering agents. Weight ratio of AA to CTS is 7.2; average molecular weight of CTS is 22.9 *104; MBA content is 2.94 wt%; APT content is 30 wt%. Conclusion • CTS, AA and APT接枝聚合後，使用NaOH 中和，可得到新穎的超吸水複合材料。 • CTS的 -OH, -NH2, -NHCO和APT的-OH會與 AA接枝聚合成水膠。 • 以TGA和SEM觀察其材料可看出，添加 APT後，可以增加材料的熱穩定性及其網狀 結構的孔洞會更加緊實。 • 少量的APT可改善CTS-g-PAA的吸水性。