【摘要】 分析壳聚糖棒材在湿态环境下力学性能衰减速率过快的原因,通过对植物叶拒水机理的仿生,将壳聚糖表面进行复合式仿生疏水改性.先对壳聚糖棒材表面进行酰化改性,降低了棒材表面极性,使棒材表面形成一种微观凹凸的粗糙结构.然后在此粗糙结构上进行生物酯涂覆,以达到仿植物叶的拒水效果.结果表明,壳聚糖棒材表面经过乙酰化处理,表面变得粗糙.经接触角实验和吸水速率测试表明,壳聚糖棒材表面经酰化改性后,降低了材料表面的极性及亲水性.通过控制酰化反应时间,能有效地增大棒材的接触角,使得最外层的生物酯涂层紧密结合,经模拟体液浸泡实验,该材料3个月内完全拒水,达到了预期的目的.更多还原

【Abstract】 In-situ precipitation method was developed to prepare chitosan rod. But high water penetrating rate and large amount of water absorption of chitosan rod limit its practical application as internal fixation of bone fracture. Many terrestrial plants and animals are water-repellent. It was believed that water-repellency is based on the surface roughness caused by different microstructures, together with the waterproof properties of the epicuticular wax. The surface acetylation and bio-ester coating were adopted as the method of surface waterproof modification of chitosan rod. Firstly, a scraggy surface was obtained though the surface acetylation of chitosan rod. Subsequently bio-ester was coated onto the modified surface. Then the final waterproof effect was characterized by contact angle and water absorption rate also. Soaked in the simulated body fluid(SBF) for three months, little mechanical properties attenuation shows that the surface composite modification is a method with a feasibility to improve the waterproof property of the chitosan rod.更多还原