N-羧丙酰壳聚糖钠增强改性壳聚糖棒材

采用原位沉析法制备N-羧丙酰壳聚糖钠增强改性的三维壳聚糖复合棒材, 并用傅里叶变换红外(FTIR)光谱、X射线衍射(XRD)、热重(TG)分析、扫描电镜(SEM)以及力学性能测试等方法研究复合棒材结构与性能之间的关系. FTIR分析表明, 壳聚糖分子中的氨基官能团和乙酰氨基官能团均与N-羧丙酰壳聚糖钠分子中的羧酸盐官能团发生强烈的静电相互作用. 加入N-羧丙酰壳聚糖钠后: 两种分子间产生强烈的静电相互作用, 限制了大分子链的运动, 使得大分子链趋于刚性, 同时复合棒材的层状叠加结构变得更加紧密, 提高了复合棒材的热稳定性与力学性能; 大分子链的刚性增强, 限制了分子链排入晶格, 从而降低了壳聚糖的结晶度. 当复合棒材中含有15% (w)的N-羧丙酰壳聚糖钠时, 其弯曲强度和弯曲模量可达156.0 MPa、5.3 GPa, 与纯壳聚糖棒材相比, 分别提高了68.8%、29.3%.因此, N-羧丙酰壳聚糖钠可有效地增强改性三维壳聚糖棒材, 该三维复合物棒材有望用作骨折内固定材料.

Chitosan Rods Reinforced by N-Carboxyl Propionyl Chitosan Sodium

N-carboxyl propionyl chitosan sodium (CPCS) was used to reinforce chitosan (CS) rods by an in-situ precipitation method.Fourier transform infrared (FTIR) spectroscopy,X-ray diffraction (XRD),thermogravimetric (TG)analysis,scanning electron microscopy (SEM),and mechanical test were used to study the properties of the composite rods.The FTIR spectra confirmed that the amino and acetamido groups on CS had a strong electrostatic attraction to the carboxylate groups on CPCS.The XRD patterns showed that the crystals in CS were destroyed because of the addition of CPCS.The thermal stability of the CPCS/CS composite rods was better than those of pure CS rods and pure CPCS as a strong interaction exists between CS and CPCS molecules.The layer-by-layer structure of the CPCS/CS composite rods became tighter compared with that of pure CS rods,which resulted in improved mechanical properties for the composite rods.As 15% (w) CPCS in the composite rods,the bending strength and the bending modulus were 156.0 MPa and 5.3 GPa,which increased by 68.8% and 29.3% compared with that of pure CS rods,respectively.Therefore,CPCS reinforces CS rods effectively and these composite rods with excellent mechanical properties can be used in novel biomedical devices to fix the bone fracture.