Kristalisanje koncentrovanih rastvora celuloze u N-metilmorfolin-N-oksidu

Abstract

U istraživanju mogućnosti dobijanja hemijskih celuloznih vlakana bez upotrebe ugljen disulfida posebna pažnja je posvećena takvim direktnim rastvaračima celuloze kao što su tercijerni amini. U ovom radu proučavane su pojave pri očvršćavanju koncentrovanih rastvora celuloze u N-metilmorfolin-N-oksidu monohidratu (NMMO). Kristalizacija je praćena u dužem vremenskom periodu (neposredno od trenutka očvršćavanja do tri meseca). Struktura rastvora celuloze u NMMO, kao i struktura regenerisanih celuloznih filmova ispitivana je optičkom mikroskopijom. Uočena je zavisnost između koncentracije celuloze u rastvoru i brzine kristalizacije, kao i njen uticaj na veličinu formiranih sferolita. Prečnik nastalih radijalnih sferolita bio je do 150µm. Na kraju treba napomenuti da stepen polimerizovanja upotrebljene celuloze nije uticao na veličinu sferolita, što je u skladu sa prethodnim istraživanjima.

Is research of possibility to obtain man-made cellulose fibers without use of carbondisulphide a special attention was given to those direct solvents of cellulose such as tertiary amines. In this paper some phenomena were studied concerning solidification of concentrated cellulose solutions in N-methylmorpholine-N-oxide monohydrate (NMMO). Crystallization was followed in a longer period (directly from the moment of solidification up to three months). Structure of cellulose solution in NMMO as well as the structure of regenerated cellulose films were tested by optical microscopy. Dependence was observed between concentration of cellulose in solution and the speed of crystallization, as well as its influence to the size of the formed spherulite. Diameter of developed radial spherulites was up to 150µm. One should note at the end that degree of polymerization of used cellulose did not influence to the size of spherulites being in accordance with the previous researches.