季铵阳离子型接枝淀粉浆料的浆膜性能

Film properties of starch sizing grafted by quaternary ammonium cations

为提高淀粉浆料的使用性能,通过调整3-丙烯酰胺丙基三甲基氯化铵(ATC)和酸解淀粉(ATS)的质量比,合成了不同接枝率的3-丙烯酰胺丙基三甲基氯化铵接枝淀粉(S-g-PATC)。借助傅里叶变换红外光谱仪对ATS和S-g-PATC进行分子结构表征,研究了S-g-PATC的膨胀度和浆膜的力学性能、结晶度、吸湿率、水溶速率。结果表明:用季铵阳离子对淀粉接枝变性可增大淀粉的膨胀度,降低浆膜的结晶度,提高浆膜的吸湿率和水溶速率;用季铵阳离子对淀粉接枝变性可提高浆膜的韧性,改善淀粉浆膜"硬而脆"的属性和淀粉浆料的退浆性能;当接枝率由2.8%增加到10.6%,S-g-PATC浆膜的断裂伸长率由2.56%增加到3.92%,而浆膜断裂强度则由28.04 MPa减小到24.27 MPa。

In order to enhance the application property of starch used as sizing agent,starch-grafted 3-acrylamidopropyl trimethylammonium chloride(S-g-PATC)samples with different grafting ratios were synthesized by changing the mass ratio of 3-acrylamidopropyl trimethylammonium chloride(ATC)to acid-thinned starch(ATS).The molecular structures of ATS and S-g-PATC were characterized by Fourier transformation infrared spectrometry.The swelling power of S-g-PATC and the mechanical properties,the degree of crystallinity,the moisture regain of its film and the time required for breaking its film in water were studied.The results show that graft modification of starch by quaternary ammonium cation increases the swelling power of starch,reduces the degree of crystallinity of film,and enhances the moisture regain of film and the time required for breaking film in water.The graft modification of starch by quaternary ammonium cation enhances the toughness of film,and improves the rigid and brittle properties of starch film and the desizing property of starch used as sizing agent.When the grafting ratio is increased from 2.8%to 10.6%,the breaking elongation of S-g-PATC film is increased from 2.56%to 3.92%,while the tensile strength is decreased from 28.04 MPa to 24.27 MPa.