Abstract:

BACKGROUND: High strength, high modulus controllable degradable and absorbable internal fixation bone substitutes the metal implant which is currently clinically used and present with biological stability, thus avoiding the metal implant from inflammation, too high elastic modulus, and requirement to perform secondary operation.
OBJECTIVE: To synthesize unsaturated polyester amide resin and to observe the influence of various initiator-accelerants on its initial setting time at room temperature, as well as polymer mechanics and degradation properties after cross-linking.
METHODS: Using maleic anhydride, phthalic anhydride, ethylene glycol, 1,2-propanediol, neopentyl glycol, caprolactam, unsaturated polyester amide resin prepolymer was synthesized with melt polycondensation method, and was then characterized. Using vinyl acetate as the cross-linking agent, adding a certain amount of initiator-accelerants for pre-crosslinking agent at room temperature, followed by heat treatment, the high-strength, fully degradable polyester amide polymer was deeply cross-linked. The influence of various initiator-accelerants on initial setting time of unsaturated polyester amide resin at room temperature, as well as polymer mechanics and degradation properties after cross-linking, were observed.
RESULTS AND CONCLUSION: The synthesized, unsaturated polyester amide resin oligomer has a good performance, which can meet the requirement of cross-linking; different types of initiator-accelerants exhibited various impacts on the gel time of unsaturated polyester amide resin pre-crosslinking at room temperature. The mechanism underlying crosslinking was different; Following the heat treatment of the deep cross-linking, resin ionomer degraded in simulated body fluid, indicating good mechanical strength retention capacity. Preliminary results show that this material can be developed into a fully degradable bone internal fixation material.