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为提高淀粉/聚乙烯醇(PVA)复合膜在纺织上浆等以薄膜为基础的应用领域中的使用效果,通过两步法合成了季铵盐醚化-顺丁烯二酸酯化淀粉(QMS),以QMS/PVA复合膜的断裂强度、断裂伸长率和耐挠曲疲劳性为量化指标,探索了QMS的改性程度(季铵盐醚化和顺丁烯二酸酯化改性程度之和)对QMS/PVA复合膜的增韧规律,考察了PVA与QMS的质量比对这种复合膜韧性的影响.研究发现:QMS/PVA复合膜的断裂强度由改性前的21.6 MPa逐渐降低到QMS改性程度为0.061的14.8 MPa,断裂伸长率和耐挠曲次数分别由26.6％和4 348次逐渐提高到29.5％和5 388次;QMS/PVA复合膜的断裂伸长率和耐挠曲次数由PVA与QMS的质量比为0的3.35％和2 128次逐渐增加到质量比为100％的43.9％和7 889次,而断裂强度由27.1 MPa逐渐下降为12.1 MPa.由此表明PVA与QMS的质量比是QMS/PVA复合膜韧性的主要影响因素,综合各指标PVA与QMS的质量比约为66.7％时为宜.

In order to improve the usability of starch/polyvinyl alcohol (PVA) composite film in the application based on the films such as warp sizing in textile,the preparation of quaternized-maleated cornstarch (QMS) was performed by a method of two-step reaction.In terms of the tensile strength,the breaking elongation,the flex fatigue resistance,and the toughening law of modification level (the sum of quaternization level and maleation one) on QMS/PVA composite films was explored,and the effect of mass ratio of PVA to QMS on the toughness of QMS/PVA composite films was also investigated.It can be found that the tensile strength of QMS/PVA composite films reduces from 21.6 MPa to 14.8 MPa,and the breaking elongation and the number of bending of QMS/PVA composite film increase from 26.6％ to 29.5％ and from 4 348 cycles to 5 388 cycles when the modification level of QMS is 0.061.When the mass ratios of PVA to QMS changes from 0 to 100％,the elongation of QMS/PVA composite films rises from 3.35％ to 43.9 ％,the number of bending increases from 2 128 cycles to 7889 cycles,and the strength decreases from 27.1 MPa to 12.1 MPa.These results suggest that the mass ratio is the index of actors that influences the toughness of QMS/PVA composite films.The suitable mass ratio is about 66.7％ based on the film properties.