季铵醚化-辛烯基琥珀酸酯化淀粉与PVA共混膜力学性能研究

为克服淀粉膜脆且硬的缺陷，制备季铵醚化-辛烯基琥珀酸酯化淀粉（QAS），并将它与聚乙烯醇（PVA）进行混合来制备共混膜；用X射线衍射仪进行共混膜结晶度测定，用扫描电子显微镜观察共混膜的表面形貌，研究QAS/PVA共混比和PVA结构对共混膜力学性能的影响。结果表明，QAS/PVA共混膜的结晶度比QAS膜的结晶度有所降低；随着QAS含量的增加，共混膜的断裂伸长率逐渐减小，断裂强度先减小后增大，当QAS/PVA共混比为50/50（质量比，下同）时，断裂强度达到最小值；随着PVA聚合度和醇解度的增加，共混膜的断裂强度和断裂伸长率也随之增大。

Study on Mechanical Properties of Quaternized and Octenylsuccinylated Starch/PVA Blend Films

To overcome the rigid and brittle defects in starch films,quaternized and octenylsuccinylated starch (QAS) was prepared and then mixed with poly(vinyl alcohol) (PVA) to prepare blend films. The crystallinity of the blend films was measured by X-ray diffractometer, and their surface morphology was observed with scanning electron microscope. The effects of QAS/PVA weight ratio and PVA structure on the mechanical properties of the blend films wereinvestigated. The results indicated that the degree of crystallinity of blend films was lower than that of pure QAS film. The elongation at break of blend films decreased gradually with an increase of QAS content,but their breaking strength decreased with the QAS content at first and then tended to increase. The blend films exhibitedminimum breaking strength at the QAS/PVA weight ratio of 50/50. Moreover, the breaking strength and elongation at break both increased with the increase of polymerization and alcoholysis degrees of PVA.