Dissolution, Modification And Preparation Of Aerogel Of Plant Fiber In Ionic Liquid

The paper of this work were to study the dissolution behavior of the banana fiber,sisal fiber in two ionic liquids which the banana fiber, sisal fiber as raw material, the ionic liquid [Amim]Cl, [Bmim]Cl as solvent.And the paper of this work were to study the homogeneous modification of the banana cellulose,sisal cellulose in [Amim]Cl, [Bmim]Cl. Banana cellulose aerogels materials and composite flame retardant banana cellulose aerogels were prepared via cellulose dissolution in ionic liquids([Amim]Cl) combined with frozen vacuum drying. The hydrophobic modification could make the banana cellulose aerogels had hydrophobic properties.Some important results can be drawn below:1.The ionic liquid could be used as the banana fiber and sisal fiber’s direct solvent.In the process of the dissolution,with the increasing of solution temperature,the solution time decreased. The solution temperature of banana fiber was lower than the sisal fiber and the solution temperature of the two fibers in [Amim]Cl was lower than in [Bmim]Cl. Through the determination of the banana, sisal cellulose’s polymerization degree,with the increasing of the dissolution temperature,the polymerization degree increased first,then decreased.With the increase of the dissolution time, the polymerization degree decreased. The optimal conditions for banana fiber respectively in [Amim]Cl and [Bmim]Cl:the solution temperature,dissolution time was 80°C,65 min and 100°C,163min; sisal fiber respectively in [Amim]Cl and [Bmim]Cl:the solution temperature,dissolution time was 120°C,72 min and 140°C,265 min.2.The banana cellulose and sisal cellulose were respectively homogeneous modification in ionic liquid [Amim]Cl or [Bmim]Cl, acetic anhydride as esterifying agent.The results showed that the optimal conditions of banana cellulose respectively in [Amim]Cl and [Bmim]Cl were acetic anhydride /AGU for 5:1, 80 °C, 4h, degree of substitution was 0.507; acetic anhydride /AGU for 5:1, 100 °C, 3h, degree of substitution was 0.455. The optimal conditions of sisal cellulose respectively in [Amim]Cl and [Bmim]Cl were acetic anhydride /AGU for 5:1, 90 °C, 2h, degree of substitution was 0.742; acetic anhydride /AGU for 5:1, 80 °C, 4h, degree of substitution was 0.868.3.Banana cellulose aerogels materials and composite flame retardant banana cellulose aerogels were prepared via cellulose dissolution in ionic liquids([Amim]Cl) combined with frozen vacuum drying. The results showed that the banana cellulose aerogels with small density of 0.034 ~ 0.207g/cm3; the water multiple could reach 7 ~ 14 times, the oil absorption multiple could reach 7 ~ 12 times; the microstructure was network structure, when the concentration of cellulose is 5%,the open pore network structure of the banana cellulose aerogels is the best which the pore network structure was more uniform,continuous and compact. The banana cellulose / flame retardant(magnesium hydroxide, aluminum hydroxide, ammonium polyphosphate) composite aerogels, improving the thermal stability of cellulose aerogels, cellulose / Mg(OH) 2 aerogel composite material’s thermal stability was better than the other two kinds of composite materials, the choice of magnesium hydroxide compared to the other two kinds of flame retardant was better.4.The banana cellulose aerogels which had hydrophobic properties were modified by three methyl chlorosilane, acetic anhydride. The results showed that the contact angle of the banana cellulose aerogels which modified by three methyl chlorosilane and ethanol mixed solution or acetic anhydride could reach 91.99 ° to 125.99°.The modified banana cellulose aerogels’ oil absorption multiple could reach 7 ~ 11 times and it still had good thermal stability.