A novel polymeric stabilizing system for modified lyocell solutions

Abstract

A novel polymeric stabilizer consisting of iminodiacetic acid sodium salt (ISDB) and benzyl amine (BSDB) covalently bound to a styrene/divinyl benzene copolymer were studied. Calorimetric, spectroscopic, rheological, and high performance liquid chromatography analysis revealed distinctive improvements of the thermal stability of modified Lyocell solutions compared to the unstabilized solution and to that with conventional NaOH/propyl gallate stabilizer. Segregation processes of the system cellulose/N‐methylmorpholine‐N‐oxide and autocatalytic reactions caused by carboxyl group‐containing additives are suppressed by ISDB/BSDB. Concerning to surface‐active additives, enhanced thermal stability is only received for a weakly reactive charcoal. In the case of nanoscaled carbon black modifier, autocatalytic reactions indicated by isoperibolic measures are prevented by the new polymeric stabilizer system. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 1702–1713, 2006

Degradation processes in the cellulose/N-methylmorpholine-N-oxide system studied by HPLC and ESR. Radical formation/recombination kinetics under UV photolysis at 77 K

“…The stabilized solutions show reduced concentrations compared to the unstabilised and NMMO. In fact, the used stabilizers are able to scavange highly reactive compounds, especially radicals and subsequently inhibit hazardous reactions in cellulose/NMMO solutions (Rosenau et al 2002c;Wendler et al 2006). …”

Thermal Stability of Lyocell Solutions: Experimental Results and Modeling Using Cluster Analysis and Partial Least Squares Regression

“…The collection of distillates accumulating over the whole dissolving process of cellulose in a 50 vol.-% aqueous solution of NMMO provides the opportunity to measure volatile degradation products. [13] These distillates contain water soluble compounds which will be exhausted by low pressure (approximately 35 mbar) and increasing temperature (25 to 90 8C). Aqueous materials can be measured by HPLC without any complicated sample preparation.…”

“…Iminodiacetic acid sodium salt covalently bound to a styrene/divinyl benzene copolymer -TP207 (ISDB; Bayer AG, Leverkusen, Germany) and benzyl amine covalently bound to a styrene/divinyl benzene copolymer -VPOC1065 (BSDB; Bayer AG, Leverkusen, Germany) were applied as stabilizers. [13] …”

Trace element status of activated charcoals and carbon black: Influence on thermal stability of modified lyocell solutions

“…T on is enhanced by NaOH and PG being a commercialized stabilization system employed in the Lyocell process 15. However, stabilization of modified solutions, especially with surface‐active additives is a crucial issue, which is partly solved for coals of lower reactivity as reported in earlier studies 24. Stabilization of solutions with enhanced reactive charcoals (A6 and A7), special technological features must be applied as described later.…”