| 摘要 |
A process for making a phosphoester polymer comprising the recurring monomeric units of formula I: wherein: X is -O- or -NR''-, where R'' is H or alkyl; L is a divalent organic moiety; R' is H, alkyl, alkoxy, aryl, aryloxy, heterocyclic, or heterocycloxy; and n is between about 25 to 2,000, is described. The process comprises the steps of: (a) polymerizing in the presence of a solvent p moles of a di-XH compound having formula II:H-X-L-X-HII wherein X and L are as defined above, with q moles, where p APPROX q, of a phosphorodihalo compound to form a polymer of formula I, wherein n is about 12 to 1000, having a first molecular weight Mw1, wherein the solvent is present in an amount greater than about 5 ml of solvent per gram of compound of formula II; (b) removing at least about 25% of the solvent to form a more concentrated reaction mixture; and (c) further polymerizing the concentrated reaction mixture for an additional time sufficient to produce a polymer of formula I wherein n is between about 25 and 2,000, the polymer having a second molecular weight Mw2, which is significantly higher than Mw1. |
