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Effects of coagulation conditions on properties of multifilament fibers based on dissolution of cellulose in NaOH/Urea aqueous solution / Yuan Mao ; Lina Zhang ; Jie Cai ; Jinping Zhou in Industrial & engineering chemistry research, Vol. 47 n°22 (Novembre 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8676–8683 Titre : Effects of coagulation conditions on properties of multifilament fibers based on dissolution of cellulose in NaOH/Urea aqueous solution Type de document : texte imprimé Auteurs : Yuan Mao, Auteur ; Lina Zhang, Auteur ; Jie Cai, Auteur ; Jinping Zhou, Auteur Année de publication : 2008 Article en page(s) : p. 8676–8683 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Dissolution--Cellulose  NaOH/Urea  Aqueous Résumé : Effects of coagulation temperature, coagulants, and wet-spinning methods on structure and properties of novel regenerated cellulose (RC) fibers prepared from cellulose in 7.5 wt % NaOH/11 wt % urea aqueous solution on pilot scale spinning machine by one- and two-stage coagulation were investigated by tensile testing, optical microscopy, scanning electron micrograph, and wide-angle X-ray diffraction. The results indicated that H2SO4/Na2SO4 and H2SO4 aqueous solutions are potential coagulants for NaOH/urea system and fibers wet-spun from the two-stage coagulation obviously exhibited the better mechanical properties than those from the one-stage coagulation. The optimal coagulation conditions for two-stage coagulation are 10 wt % H2SO4/15 wt % Na2SO4 for the first coagulation bath and 5 wt % H2SO4 for the second bath or 5 wt % H2SO4/15 wt % Na2SO4 for the first coagulation bath and 10 wt % H2SO4 for the second bath. Moreover, the tensile strength of novel fibers increased with a drop in coagulation temperature. The diffusion rate between the coagulant and solvent plays a major role in determining the mechanical properties of the cellulose fibers. Our spinning process was quite different from that of the viscose process, in which orientation and coagulation proceed more or less simultaneously. The production method of this fiber wet-spun could be suitable in the wide range of coagulation conditions, compared to the viscose one. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800833w [article] Effects of coagulation conditions on properties of multifilament fibers based on dissolution of cellulose in NaOH/Urea aqueous solution [texte imprimé] / Yuan Mao, Auteur ; Lina Zhang, Auteur ; Jie Cai, Auteur ; Jinping Zhou, Auteur . - 2008 . - p. 8676–8683. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8676–8683 Mots-clés : Dissolution--Cellulose  NaOH/Urea  Aqueous Résumé : Effects of coagulation temperature, coagulants, and wet-spinning methods on structure and properties of novel regenerated cellulose (RC) fibers prepared from cellulose in 7.5 wt % NaOH/11 wt % urea aqueous solution on pilot scale spinning machine by one- and two-stage coagulation were investigated by tensile testing, optical microscopy, scanning electron micrograph, and wide-angle X-ray diffraction. The results indicated that H2SO4/Na2SO4 and H2SO4 aqueous solutions are potential coagulants for NaOH/urea system and fibers wet-spun from the two-stage coagulation obviously exhibited the better mechanical properties than those from the one-stage coagulation. The optimal coagulation conditions for two-stage coagulation are 10 wt % H2SO4/15 wt % Na2SO4 for the first coagulation bath and 5 wt % H2SO4 for the second bath or 5 wt % H2SO4/15 wt % Na2SO4 for the first coagulation bath and 10 wt % H2SO4 for the second bath. Moreover, the tensile strength of novel fibers increased with a drop in coagulation temperature. The diffusion rate between the coagulant and solvent plays a major role in determining the mechanical properties of the cellulose fibers. Our spinning process was quite different from that of the viscose process, in which orientation and coagulation proceed more or less simultaneously. The production method of this fiber wet-spun could be suitable in the wide range of coagulation conditions, compared to the viscose one. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800833w

Flocculation properties and antimicrobial activities of quaternized celluloses synthesized in NaOH/Urea aqueous solution / Yongbo Song in Industrial & engineering chemistry research, Vol. 49 N° 3 (Fevrier 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 3 (Fevrier 2010) . - pp. 1242–1246 Titre : Flocculation properties and antimicrobial activities of quaternized celluloses synthesized in NaOH/Urea aqueous solution Type de document : texte imprimé Auteurs : Yongbo Song, Auteur ; Jie Zhang, Auteur ; Weiping Gan, Auteur ; Jinping Zhou, Auteur Année de publication : 2010 Article en page(s) : pp. 1242–1246 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Flocculation--Antimicrobial--Quaternized--Celluloses--Synthesized  --NaOH/Urea--Aqueous--Solution Résumé : Three water-soluble quaternized cellulose derivatives (QCs) with degree of substitution (DS) values of 0.38, 0.50, and 0.74 were synthesized in NaOH/urea aqueous solutions. The flocculation characteristics of QCs have been evaluated in montmorillonite (MMT) suspensions and simulated dye (Reactive Red) aqueous solutions by spectrophotometry. The results showed that QCs were effective flocculating agents for MMT over a wide range of pH values, and the flocculation efficiency of MMT was up to nearly 100%. Decolorization efficiency of Reactive Red dye reached 93% under optimum conditions. In vitro antimicrobial activity of QC was evaluated by determining minimum inhibition concentration (MIC) values against Gram-positive bacteria (S. aureus) and Gram-negative bacteria (E. coli), respectively. The results showed that QC could strongly inhibit the growth of E. coli and S. aureus. Therefore, quaternized cellulose is applicable as a novel wastewater treatment agent with high flocculation efficiency as well as effective antimicrobial activity. Note de contenu : Bibiogra. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9015057 [article] Flocculation properties and antimicrobial activities of quaternized celluloses synthesized in NaOH/Urea aqueous solution [texte imprimé] / Yongbo Song, Auteur ; Jie Zhang, Auteur ; Weiping Gan, Auteur ; Jinping Zhou, Auteur . - 2010 . - pp. 1242–1246. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 3 (Fevrier 2010) . - pp. 1242–1246 Mots-clés : Flocculation--Antimicrobial--Quaternized--Celluloses--Synthesized  --NaOH/Urea--Aqueous--Solution Résumé : Three water-soluble quaternized cellulose derivatives (QCs) with degree of substitution (DS) values of 0.38, 0.50, and 0.74 were synthesized in NaOH/urea aqueous solutions. The flocculation characteristics of QCs have been evaluated in montmorillonite (MMT) suspensions and simulated dye (Reactive Red) aqueous solutions by spectrophotometry. The results showed that QCs were effective flocculating agents for MMT over a wide range of pH values, and the flocculation efficiency of MMT was up to nearly 100%. Decolorization efficiency of Reactive Red dye reached 93% under optimum conditions. In vitro antimicrobial activity of QC was evaluated by determining minimum inhibition concentration (MIC) values against Gram-positive bacteria (S. aureus) and Gram-negative bacteria (E. coli), respectively. The results showed that QC could strongly inhibit the growth of E. coli and S. aureus. Therefore, quaternized cellulose is applicable as a novel wastewater treatment agent with high flocculation efficiency as well as effective antimicrobial activity. Note de contenu : Bibiogra. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9015057

Primarily Industrialized Trial of Novel Fibers Spun from Cellulose Dope in NaOH/Urea Aqueous Solution / Ran Li in Industrial & engineering chemistry research, Vol. 49 N° 22 (Novembre 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 22 (Novembre 2010) . - pp. 11380-11384 Titre : Primarily Industrialized Trial of Novel Fibers Spun from Cellulose Dope in NaOH/Urea Aqueous Solution Type de document : texte imprimé Auteurs : Ran Li, Auteur ; Chunyu Chang, Auteur ; Jinping Zhou, Auteur Année de publication : 2011 Article en page(s) : pp. 11380-11384 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Aqueous  solution Résumé : Faced with the serious pollution caused by the viscose method (use of CS2), a primarily industrialized trial via a "green" wet-spinning process based on dissolution of cellulose in NaOH/urea aqueous solution precooled to -12.5 °C was performed. In a dissolution tank of 1000 L capacity, the cellulose could be dissolved completely in the NaOH/urea system within 5 min, and cellulose fibers were spun successfully from the transparent dope. A 15:10 H2SO4/Na2SO4 aqueous solution was adopted as the first coagulants in the bath, and a 5 wt % H2SO4 aqueous solution was used as the second coagulant to fabricate new regenerated cellulose fibers. There was no evaporation of any chemical agent during dissolution and regeneration. The structure of the fibers was characterized with scanning electron microscope, wide-angle X-ray diffraction, 13C NMR, and tensile testing. The cellulose fibers exhibited a bright surface and a circular section, and their tensile strength reached 1.63-1.97 cN/dtex, which is close to commercial viscose fiber, although the drawing orientation in the production process was not performed. Therefore, we created a novel and simple approach combining a nonpolluting, low-cost, and quick process for the production of cellulose fibers, which was important for environmental conservation. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23437835 [article] Primarily Industrialized Trial of Novel Fibers Spun from Cellulose Dope in NaOH/Urea Aqueous Solution [texte imprimé] / Ran Li, Auteur ; Chunyu Chang, Auteur ; Jinping Zhou, Auteur . - 2011 . - pp. 11380-11384. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 22 (Novembre 2010) . - pp. 11380-11384 Mots-clés : Aqueous  solution Résumé : Faced with the serious pollution caused by the viscose method (use of CS2), a primarily industrialized trial via a "green" wet-spinning process based on dissolution of cellulose in NaOH/urea aqueous solution precooled to -12.5 °C was performed. In a dissolution tank of 1000 L capacity, the cellulose could be dissolved completely in the NaOH/urea system within 5 min, and cellulose fibers were spun successfully from the transparent dope. A 15:10 H2SO4/Na2SO4 aqueous solution was adopted as the first coagulants in the bath, and a 5 wt % H2SO4 aqueous solution was used as the second coagulant to fabricate new regenerated cellulose fibers. There was no evaporation of any chemical agent during dissolution and regeneration. The structure of the fibers was characterized with scanning electron microscope, wide-angle X-ray diffraction, 13C NMR, and tensile testing. The cellulose fibers exhibited a bright surface and a circular section, and their tensile strength reached 1.63-1.97 cN/dtex, which is close to commercial viscose fiber, although the drawing orientation in the production process was not performed. Therefore, we created a novel and simple approach combining a nonpolluting, low-cost, and quick process for the production of cellulose fibers, which was important for environmental conservation. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23437835