摘要:
采用注射成型法制备了羟基磷灰石/聚酰胺66(HA/PA66)多孔支架, 用SEM、XRD和DSC等手段表征了支架的形貌和结构, 测试了其力学性能。研究表明, 调节注射参数(发泡剂和储料量)能控制支架的力学性能、孔径大小和孔隙率。HA能提高支架的刚性, 但使孔径和孔隙率下降。在HA/PA66(30/70, 质量比)中添加乙烯-醋酸乙烯共聚物(EVA), 可改善材料的加工性能和支架的力学性能, 有利于孔径增大和均匀孔结构的形成。注射成型法可快速便利地制备多孔支架, 使孔径控制在200~600 μm, 孔隙率超过64％, 压缩性能达到或超过人体骨小梁, 并接近人体松质骨的压缩强度。
Abstract:
Hydroxyapatite/polyamide-66 (HA/PA66) composite porous scaffolds were prepared using injection-molding technique and analyzed by means of SEM, XRD, DSC and mechanical testing. The results demonstrate that the mechanical properties, porosity and pore size of HA/PA66 composite scaffolds can be effectively controlled by changing the molding parameters (foaming agent and shot size). HA particles increase the stiffness of HA/PA66 composite scaffolds accompanied by the reduction of pore size and porosity. The addition of ethylene-vinyl acetate copolymer (EVA) in HA/PA66 (30/70, mass ratio) scaffolds conduces to the pore growth, the formation of uniform porous structure, the improvement of the scaffolds'mechanical properties and melt processability of the composites. The injection-molding method can rapidly and conveniently fabricate the composite scaffolds. The obtained scaffolds with a pore size ranging from 200 μm to 600 μm and a porosity more than 64% can simultaneously meet the requirements of porous structure and mechanical performance. The compressive properties of the scaffolds are similar to or higher than those of trabecular bone and close to those of the cancellous bone.
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