氯化锂/丙三醇改性玉米淀粉/聚对苯二甲酸-己二酸丁二醇酯复合材料的结构与性能

Structure and Properties of Lithium Chloride/Glycerol Modified Corn Starch/Poly(butylene adipate-co-terephthalate)Composite Material

为制备具有良好综合性能的淀粉(CS)/聚对苯二甲酸-己二酸丁二醇酯(PBAT)共混材料,以氯化锂(LiCl)和丙三醇(Gly)构建新型复合改性剂,提出了一步共混制备改性CS/PBAT共混材料的新方法。通过扫描电镜(SEM)、X射线衍射(XRD)、差示扫描量热分析(DSC)、力学性能测试等考察了复合改性剂中LiCl对淀粉的作用效果,探究了复合改性剂对CS/PBAT共混材料结构和性能的影响。结果表明,Gly/LiCl复合改性剂中LiCl的引入能够增强改性剂与淀粉羟基和PBAT酯基之间的电子相互作用,进一步破坏淀粉的氢键和颗粒结构,从而降低CS/PBAT的结晶度,改善淀粉与PBAT的相容性,提高共混材料的韧性、耐水性和降解性能,表现出比单纯丙三醇改性更好的作用效果。采用Gly和LiCl质量比10:1的复合改性剂,在CS和PBAT质量比为50:75时改性CS/PBAT共混材料具有优良的力学性能,其断裂伸长率从改性前的21.9%提高到了271.7%,拉伸强度从改性前的13.4 MPa变为10.8 MPa,下降不大,显示出良好的改性作用。

In order to prepare starch(CS)/poly(butylene adipate-co-terephthalate)(PBAT)blend materials with good comprehensive properties,a new composite modifier was constructed from lithium chloride(LiCl)and glycerol(Gly),and the modified CS/PBAT blend material was prepared by one-step blending method.The effect of LiCl on starch was investigated by scanning electron microscope(SEM),X-ray diffraction(XRD),differential scanning calorimetry(DSC)and mechanical properties test,and the effect of LICL on the structure and properties of CS/PBAT blend was investigated.The results show that the introduction of LiCl in Gly/LiCl could enhance the electronic interaction between the modifier and starch hydroxyl group and PBAT ester group,further destroy the hydrogen bonds and particle structure of starch,thereby reducing the crystallinity of CS/PBAT and improving the compatibility of starch and PBAT.The toughness,water resistance and degradation properties of the blend material are improved,and the effect is better than that of pure glycerol modification.The modified CS/PBAT blend prepared by one-step blending method with m(Gly):m(LiCl)=10:1 and m(CS):m(PBAT)=50:75 has excellent mechanical properties,and its elongation at break is increased from 21.9%to 271.7%.The tensile strength decreases little from 13.4 MPa to 10.8 MPa,showing a good modification effect.