Patent ID: 6028163
Filing Date: 2000-02-22
Classification: C08G

Abstract:
A process for preparing a high molecular weight poly(phosphoester) comprising the recurring monomeric units of formula I: ##STR13## wherein: X is --O-- or --NR""--, where R"" is H or alkyl;L is a divalent organic moiety, with the proviso that L cannot have the formula ##STR14## R' is H, alkyl, alkoxy, aryl, aryloxy, heterocyclic, or heterocycloxy; and n is from about 25 to 2000,said process comprising the steps of:(a) substantially dissolving p moles of a di-XH compound having formula II:H--X--L--X--H IIin a solvent comprising at least 75% toluene by volume at a first temperature between about -75.degree. C. and +60.degree. C. to form a reaction mixture;(b) while maintaining the reaction mixture at the first temperature, adding q moles, where p.apprxeq.q, of a phosphorodihalo compound of formula III: ##STR15## wherein R' is defined as above and ""halo"" is Br, Cl or I; (c) gradually increasing said first temperature at a rate of less than about 2.degree. C. per minute as necessary to achieve a second temperature between about 0.degree. C. and 150.degree. C., and mixing the reaction mixture at the second temperature to form the polymer of formula I; and(d) isolating the polymer of formula I.