| 摘要 |
A polymer of a vinyl aromatic compound <FORM:0909673/IV(a)/1> wherein X is H or C1 to C4 alkyl and R is H or C1 to C2 alkyl, in which the polymer molecules contain terminal hydroxyl units, may be prepared by terminating an anionic polymerization of the vinyl aromatic compound by a terminating agent <FORM:0909673/IV(a)/2> wherein R1 is H, alkyl or phenyl and R2 is H or alkyl, and then contacting the terminated product with a proton donor, e.g. an alcohol, water or a mineral acid. The anionic polymerization may be in a liquid, such as a hydrocarbon, an ether or ammonia, and may be catalysed with an alkali metal or an organo-compound of an alkali metal (many of which are specified), including sodium-a -methyl styrene tetramer; active polyisoprene containing sodium, butyl sodium or phenyl lithium catalyst; dialkali metal compounds and polycyclic aromatic hydrocarbon/sodium compounds. Of the specified terminating agents, those preferred are formaldehyde, acetaldehyde, benzaldehyde and acetone. The hydroxyl containing products may be after-treated and/or cross-linked by reaction with polyisocyanates /sB water. |
