热塑性淀粉的制备及在聚乳酸复合材料中的应用

Preparation and Characterization of Thermoplastic Starch and Its Application in Polylactide Composite

通过糠基缩水甘油醚(FGE)的化学接枝改性,成功制得具有优异熔融加工性能的热塑性淀粉。红外光谱和核磁共振氢谱分析表明,通过马来酸酐的桥接作用,FGE成功接枝到淀粉分子上。X射线衍射分析发现,FGE的接枝能有效破坏淀粉的晶体结构,从而赋予FGE接枝淀粉(FGE-g-St)优异的热塑性加工性能。动态接触角测试发现,FGE-g-St的接触角从原淀粉(N-St)的30°左右提高至65°左右,表现出极其优异的疏水性能,从而显著改善了FGE-g-St与聚乳酸的界面相容性。相对于PLA/N-St复合材料,PLA/FGE-g-St复合材料的拉伸强度、弯曲强度和断裂伸长率均得到显著提高,这得益于其优异的界面相容性。

A thermoplastic starch was achieved by the grafting modification of furfuryl glycidyl ether(FGE).The FT-IR and~1H-NMR analyses demonstrate that the furan rings are successfully grafted onto starch molecules through the bridging effect of maleic anhydride.XRD results show that the crystal structures of starch are effectively destroyed by the grafting modification of FGE,then endowing starch with excellent thermoplastic processing properties.In addition,the FGE-grafted starch(FGE-g-St)displays extremely excellent hydrophobicity,which is demonstrated that the contact angle is increased from about 30°for native starch(N-St)to about 65°.This results in the significantly improved interface compatibility between FGE-g-St and polylactide(PLA),reflected by the almost detectable phase interface in the PLA/FGE-g-St composite.Compared with the PLA/N-St composite,the tensile strength,flexural strength and elongation at break of the PLA/FGE-g-St composite are increased comprehensively,which is attributed to the significantly improved interface compatibility.