| 摘要 |
<p>A method of making a solution of a polysaccharide, particularly cellulose, in an aqueous tertiary amine N-oxide solvent which exhibits good thermal stability is disclosed. The solution contains at least one compound selected from the group consisting of compounds of the formula ArCR<1>=NNR<2>R<3>, where Ar represents an aromatic group which comprises an aromatic ring having six pi-electrons and substituted by a hydroxy group in the ortho position, optionally further substituted on the aromatic ring; R<1> represents hydrogen or C1-C4 n-alkyl; R<2> represents hydrogen, C1-C4 alkyl or C6-C10 aryl; and R<3> represents hydrogen, C1-C4 alkyl, C6-C10 aryl or R<4>CO, where R<4> represents hydrogen, C1-C4 alkyl, C6-C10 aryl, XCONR<2>NH2 or XCONR<2>N=CR<1>Ar, where X represents a chemical bond, a C1-C4 alkylene or C2-C4 alkylidene group or a C6-C10 arylene group; or R<2> and R<3> together represent ArCR<1>; and of one or more precursors of such compounds; and of compounds of the formula R<5>CONR<1>NH2 wherein R<5> represents hydrogen, C1-4 alkyl, C6-10 aryl or XCONR<1>NH2. When the groups R<2>, R<3> and R<4> are alkyl or aryl groups, they may optionally be substituted alkyl or aryl groups. When the groups R<2>, R<3> and R<4> are aryl groups, they may optionally be carbocyclic or heterocyclic aryl groups. The solutions are suited to being formed into extruded articles such as fibres and films.</p> |
