| abstract |
An improved process for preparing an aromatic polyanhydride is disclosed. The aromatic polyanhydride is prepared by reacting an aromatic dicarboxylic acid with an anhydride to form an anhydride prepolymer, isolating and purifying the prepolymer, and subjecting the prepolymer to melt polycondensation conditions. The improvement specifically relates to the purification of the acid so it is essentially free of impurities before it is reacted with the anhydride. n The polymers prepared from the improved process have higher molecular weights than the molecular weights achieved from the prior art processes, and exhibit outstanding thermal stability and mechanical properties. This combination of properties allows the aromatic polyanhydrides to be melt processed to prepare numerous devices. In addition, these aromatic polyanhydrides are bioabsorbable, and this attribute in combination with its ability for melt processing makes the polyanhydrides particularly well-suited for the preparation of implantable surgical devices such as wound closure devices which are designed to absorb in the body when exposed to moist bodily tissue. |