TAILIEUCHUNG - The effect of the duration of alkali treatment on the solubility of polyoses
Holocelluloses from the wood of pine and oak species growing naturally in Turkey were extracted with 5% KOH solution under specified conditions, and soluble polyoses and lignin were examined. | Tr. J. of Agriculture and Forestry 23 (1999) 667-671 © TÜBİTAK The Effect of the Duration of Alkali Treatment on the Solubility of Polyoses Mualla BALABAN, Güneş UÇAR İstanbul Üniversitesi, Orman Fakültesi Orman Ürünleri Kimyası ve Teknolojisi 80895 Bahçeköy, İstanbul-TURKEY Received: Abstract: Holocelluloses from the wood of pine and oak species growing naturally in Turkey were extracted with 5% KOH solution under specified conditions, and soluble polyoses and lignin were examined. The extractions of both pine and oak wood holocelluloses followed the mechanism of second order reaction. While the glucomannan of pine was poorly dissolvable during the extraction, xylan, the main polyose of hardwoods, was removed very efficiently upto almost 90 %. The solubility of xylane also obeyed the some kinehes. By the equation [A ]1-n - [A0]1-n = (n -1) kt, where n =2, for the second order mechanism, kinetic parameters [AO] and k were calculated to be , for pine and , 0,03018 for oak. Using these kinetic parameters, the predicted yields were in very close agreement with their counterparts from the experiments. Moreover, the holocelluloses and certain residues obtained after alkali were analyzed with regard to their anhydromonosaccharides. Galactoglucomannan, the main polyose of pine wood, was resistant to alkali, and about half of the more easily soluble arabinoxylane was removable. In contrast to mannane, nearly 90% of the hard wood xylane was dissolved by alkali, and its extraction also followed the second order mechanism. Thereafter, the kinetic parameters related to this extraction were calculated. Alkali ile İşlem Süresinin Polyozların Çözünürlüğü Üzerine Etkisi Özet: Ülkemizde doğal olarak yetişen çam ve meşe gibi iki önemli iğne yapraklı ve yapraklı ağaç odunlarından elde edilen holoselüzlor %5’lik KOH çözeltisi ile belli koşullar altında ekstrakte edilmiştir. İşlem sırasında polyozların, özellikle çözünür polyozlar ile .
đang nạp các trang xem trước
