生物基高吸水温敏性水凝胶的制备及性能表征

Preparation and characterization of bio based superabsorbent thermosensitive hydrogel

为进一步有效抑制煤炭自燃,以海藻酸钠和羧甲基纤维素为基体,以聚乙烯醇和N-异丙基丙烯酰胺为单体,采用接枝共聚技术制备了一种生物基高吸水性温敏水凝胶。采用傅里叶红外光谱、热重实验以及扫描电子显微镜对凝胶的微观结构进行表征,通过溶胀动力学实验研究水凝胶的吸水倍率,探究引发剂和交联剂对LCST影响。结果表明,温敏性防灭火凝胶成功合成,具有较高的热稳定性,致密的结构有利于保持凝胶内部的水分,可隔离煤与氧的接触。水凝胶抑制煤自燃特性分析表明,凝胶对煤的氧化有明显的抑制作用。此外,N,N’-亚甲基双丙烯酰胺和过硫酸钾用量的增加均会降低LCST,水凝胶在不同的温度下可实现溶胶与凝胶之间的相态转变,更好的实现煤炭火灾的防控。

In order to further effectively inhibit the spontaneous combustion of coal,a kind of bio based superabsorbent thermosensitive hydrogel was prepared by grafting copolymerization technology with sodium alginate and carboxymethyl cellulose as matrix,polyvinyl alcohol and N-isopropylacrylamide as monomers.The microstructure of the gel was characterized by Fourier transform infrared spectroscopy,thermogravimetry and scanning electron microscopy.The water absorption of the hydrogel was studied by swelling kinetics experiments,and the effects of initiator and crosslinker on LCST were explored.The results showed that the temperature sensitive fire prevention and extinguishing gel was successfully synthesized and had high thermal stability.The compact structure was conducive to maintaining the moisture in the gel and isolating the contact between coal and oxygen.The increase of Methylene-Bis-Acrylamide and potassium persulfate will reduce LCST,and the hydrogel can realize the phase transformation between sol and gel at different temperatures,so as to better realize the prevention and control of coal fires.