Polyanhydrides. IV. Unsaturated and crosslinked polyanhydrides

Abstract

Unsaturated polyanhydrides of the structure [(COCHCHCOO)x(CORCOO)y]n, were synthesized. The polymers were prepared by either melt or solution polycondensation. Weight average molecular weights of up to 30,000 were obtained. The double bonds remain intact throughout the polymerization process and were available for a secondary reaction to form a crosslinked matrix. Poly(fumaric acid) is crystalline and insoluble in common organic solvents. Copolymers of fumaric acid with aliphatic diacids are less crystalline and soluble in chlorinated hydrocarbons. These copolymers displayed nearly constant degradation rates and drug release rates under physiological conditions. The time for complete degradation of 14 × 1.5 mm discs of poly(fumaric anhydride) and poly(sebacic anhydride) occurred in 2 and 15 days, respectively, while their copolymers degraded within this range. Further crosslinking of the polyanhydrids is demonstrated.

Polyanhydrides

“…A detailed analysis of the copolymers of SA with the aromatic and unsaturated monomers, CPP, CPH, FA, and trimellitic -amino acid derivative, showed that copolymers with high ratios of SA and CPP, TMA -gly, or CPH were crystalline while copolymers with equal ratios of SA and CPP or CPH were amorphous [69] . In contrasts, the poly(FA -SA) series displayed high crystallinity regardless of comonomer ratio [72] . Aliphatic polyanhydrides generally melt at lower temperatures than do aromatic polyanhydrides.…”

Characterization of polysuccinate and hydroxyapatite-based nanocomposites containing poly(ester-anhydride) microspheres

“…PEA was synthesized in two‐step procedure. First, the prepolymer was prepared according to the literature . Briefly, OSAGE and SBA were mixed in ratio 20:80 w/w and refluxed in acetic anhydride (1/10 w/v ) under nitrogen for half an hour.…”

Biodegradable poly(L‐lactide) and polycaprolactone block copolymer networks

“…Hydroxyl‐terminated oligomers have been functionalized to obtain acrylated or methacrylated poly(α‐hydroxy acid) 30–35. In this way, crosslinked polyanhydrides have been synthesized from crosslinkable precursors that contain labile anhydride bonds 36–40…”