以三氟乙酸在无水条件下溶解脱脂棉纤维,在壳聚糖的醋酸溶液中析出.脱脂棉纤维均匀稳定地分散在粘稠的壳聚糖溶液中,采用原位沉析法制备得到脱脂棉纤维增强的具有层状叠加结构的壳聚糖棒材.经力学性能测试表明,当脱脂棉的质量分数为0.2%时,复合棒材的弯曲强度达136.8MPa,与纯壳聚糖棒材相比提高了48%.SEM表明,脱脂棉纤维与壳聚糖基体界面结合性能好,复合棒材在受到外力作用时,壳聚糖基体传递应力,而脱脂棉纤维可以有效承担外界应力的作用,从而使得微量的脱脂棉纤维有效地提高了壳聚糖棒材的弯曲强度,该材料有望用于临床骨折内固定.
Absorbent cotton fibers were dissolved in trifluoroacetic acid (TFA), and then precipitated in the chitosan solution. Cotton fibers were equably stably suspended in the viscous chitosan solution. Cotton fiber/chitosan composite rods with layer-by-layer structure were constructed via in-situ precipitation. Mechanical property tests showed that the bending strength of cotton fiber/chitosan composite rod reached 136.8 MPa, which was increased by 48%, compared with the pure chitosan rod, when the content percentage of absorbent cotton in the composites was 0.2%. Scanning electron microscope (SEM) indicated that the interface between the cotton fiber and chitosan matrix was well connected. Chitosan was the continuous phase that could transfer stress, whereas cotton fiber could endure outside stress effectively. Thus, chitosan rod could be reinforced by a small amount of cotton fibers to suit internal fixation of bone fracture.