蔗渣纤维与丁二酸酐反应的研究

Study on the Reaction between Sugarcane Bagasse and Succinic Anhydride

以蔗渣为原料,探讨了丁二酸酐改性的影响因素,并采用FT-IR半定量法进行了表征。研究发现,采用丁二酸酐直接处理蔗渣可以将羧基引入蔗渣中,羧基化的程度随着反应时间、酸酐用量、反应温度的提高而提高。在超声波处理时间30 m in、反应时间60 m in、反应温度115℃、丁二酸酐与蔗渣质量比1.25∶1的条件下,蔗渣与环状酸酐反应后的质量提高百分数(WPG)为39.4%。采用CP/MAS13C NMR对反应前后的蔗渣试样进行了表征,探讨了反应机理,发现反应后纤维素结晶指数降低,表明碳水化合物和木质素均参与了化学反应。

Carboxylation of unprocessed sugarcane bagasse with succinic anhydride under ultrasound irradiation was studied. The effects of ultrasound-irradiating time, reaction time, reaction temperature, and anhydride dosage on the reaction were discussed. The extent of carboxylation was measured by the weight percent gain （WPG）. FT-IR spectra of unmodified and carboxylated bagasse were also used to characterize the effects of experimental conditions on carboxylation. The results showed that modification of bagasse with succinic anhydride is an efficient method for preparation of products containing carboxylic groups. Increases of reaction time, anhydride dosage, and reaction temperature led to increment of WPG under given experimental conditions. A WPG of 39.4 % was achieved under the condition of uhrasound-irradiation time 30 min, reaction time 60 min, succinic anhydride dosage by the ratio of anhydride to dried bagasse 1.25 ： 1, and reaction temperature 115℃. The samples were also characterized by CP/MAS 13C NMR spectroscopy. It was found that during treatment of sugarcane bagasse with succinic anhydride under the conditions used, both polysaccharide and lignin participated the reaction. The crystallinity indexes of cellulose in sugarcane bagasse decreased after chemical modification.