脂肪族聚氨酯/磷灰石复合材料的原位制备及性能

Preparation and properties of aliphatic polyurethane/hydroxyapatite composites by in situ polymerization

为避免芳香族聚氨酯在体内降解时产生有毒物质,选用生物相容性良好的脂肪族聚氨酯(PU)与生物活性的羟基磷灰石(HA)为原料,通过原位聚合法制备了脂肪族PU/HA组织工程用多孔支架,并采用SEM、IR和力学试验等方法对多孔支架的形貌和性能进行了表征,进一步研究了发泡剂(水)用量和HA含量对支架泡孔结构和力学强度的影响。结果表明,当发泡剂用量为1%～1.5%(质量分数)时制得的多孔PU/HA复合支架材料孔隙之间相互贯通,孔径范围分布在300～800μm,大孔壁上分布着孔径为50～200μm的小孔,孔隙率达80%以上。随HA含量增加,支架抗压强度和弹性模量显著上升。综合考虑HA的增强效果和组织工程支架的孔隙结构,本体系中HA的最佳添加量为40%(质量分数),发泡剂的最佳用量为1%(质量分数)。

In order to avoid toxic degradation products of aromatic polyurethanes in vivo,aliphatic polyurethanes with good biocompatibility and bioactive hydroxyapatite were selected to fabricate porous PU/HA scaffolds for tissue engineering by in situ polymerization.The morphology and properties of the scaffolds were characterized by SEM,IR,and mechanical testing.The effects of the amount of blowing agent（water） and HA content on the pore structure and mechanical strength of scaffolds were investigated.The results indicate that when adding 1wt%-1.5wt% blowing agent into PU,the scaffolds possess interconnected porous structure with a pore size mainly ranging from 300 to 800μm,and 50-200μm micropores existed on the pores＇ walls,the porosity of the scaffolds is more than 80%.The compressive strength and modulus of the composite scaffolds show higher enhancement with increasing HA content.Considering comprehensively the reinforcing effect of the HA filler and the open porous structure for tissue engineering scaffold,in this system,the optimal addition of HA particles in polyurethane can be 40wt% and the optimal amount of blowing agent can be 1wt%.