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Synthesis and prope...
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Zhou, QiKTH,Bioteknologi
(författare)
Synthesis and properties of O-2- 2-(2-methoxyethoxy) ethoxy acetyl cellulose
- Artikel/kapitelEngelska2001
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Nummerbeteckningar
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LIBRIS-ID:oai:DiVA.org:kth-20301
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https://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-20301URI
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https://doi.org/10.1002/1099-0518(20010201)39:3<376::AID-POLA1004>3.3.CO;2-QDOI
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Språk:engelska
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Sammanfattning på:engelska
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Klassifikation
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Ämneskategori:ref swepub-contenttype
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Ämneskategori:art swepub-publicationtype
Anmärkningar
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QC 20100525
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In this article, a series of O-2-[2-(2-methoxyethoxy)ethoxy] acetyl celluloses with different degree of substitution (DS) values was synthesized by a homogeneous reaction of cellulose with 2-[2-(2-methoxyethoxy)ethoxy] acetyl chloride in a 10% (w/w) dimethylacetamide/lithium chloride solution, combined with pyridine as the acid acceptor. The total DS values of the derivatives in anhydroglucose units was determined by H-1 and C-13 NMR spectra, and ranged from 0.4 to 3.0, depending on the amount of acid chloride in the reaction. The effects of the total DS values and the O-2-[2-(2-methoxyethoxy)ethoxy]acetyl acetyl substituent distribution on the solubility of the derivatives were investigated. The lowest limit of the DS value for water-soluble 0-2-[2-(2methoxyethoxy)ethoxy]acetyl cellulose was approximately 0.5, which is lower than that of methylcellulose. The amphiphilic derivatives with higher DS values than 1.7 exhibited a good solubility in both water and organic solvents, such as dimethyl sulfoxide, tetrahydrofuran, and chloroform. Sol-gel transition in aqueous solution was observed for the amphiphilic derivatives with a higher DS value than 1.7; the precipitation temperature (T-p) decreased as the DS value increased, showing that the derivatives are highly temperature sensitive. The thermal properties of the fully substituted derivative were measured using polarized microscopy, DSC, and X-ray diffraction; and are dis cussed in terms of phase transition of the sample derivatives.
Ämnesord och genrebeteckningar
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cellulose ester
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degree of substitution
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sol-gel transition
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thermotropic liquid crystal
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substituent distribution
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acetylated derivatives
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flexible substituents
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water solubility
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excluded-volume
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polymers
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c-13-nmr
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acetate
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ethers
Biuppslag (personer, institutioner, konferenser, titlar ...)
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Zhang, L. N.
(författare)
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Okamura, H.
(författare)
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Minoda, M.
(författare)
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Miyamoto, T.
(författare)
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KTHBioteknologi
(creator_code:org_t)
Sammanhörande titlar
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Ingår i:Journal of Polymer Science Part A39:3, s. 376-3820887-624X1099-0518
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