| 摘要 |
<p>Covers polyester polycarbonates of the structure: <IMAGE> wherein X and Y, independently, are H, methyl, or ethyl, m and n independently are integers of 1-5, R is a nucleus of a glycol selected from the group of lower alkylene glycols and polyalkylene glycols of up to about 600 molecular weight, Z is an organic radical from a cyclic organic acid anhydride having 4-20 carbon atoms, and r is an integer of 1-5. Also covers a method of preparing said polyester polycarbonates as well as polyurethanes derived therefrom, as well as polyisocyanurate polymers containing both isocyanurate linkages and urethane linkages.</p> |
