己酸酯淀粉的制备及其上浆性能

Preparation and sizing properties of caproylated starch

为开发适合疏水性纤维特别是聚乳酸纤维经纱上浆的变性淀粉浆料品种,以己酸酐(CA)为酯化剂,通过改变其用量制备了不同取代度的己酸酯淀粉(CS)。对CS颗粒结构进行了红外光谱分析,探究了己酸酯化变性对淀粉浆液性能、浆膜力学性能的影响。结果表明:经己酸酯化变性后,淀粉浆液的黏度热稳定性、淀粉对聚乳酸和涤纶纤维的黏附性及淀粉膜的断裂伸长率均得到了提升,膜的断裂强度有所降低;CS对2种纤维的黏附力,在取代度小于0.025时逐渐提高,且在0.025时取得最大值,然后随取代度增加而有所降低;CS膜的断裂伸长率随取代度增大而提高,断裂强度逐渐降低;CS浆液的黏度热稳定性逐渐降低,但均高于酸解淀粉。

In order to provide a suitable modified starch for warp sizing of hydrophobic fibers especially for polylactic acid(PLA)fibers,caproylated starch(CS)samples with different degrees of substitution were prepared by using caproic anhydride as esterifying agent.The structure of CS was characterized by Fourier transform infrared analysis.The influence of the caproylation on paste and film properties was investigated.The results show that the caproylation could enhance viscosity stability of gelatinized starch paste,its adhesion to polylactic acid and polyester fibers,and breaking elongation of starch film.In addition,the modification causes decrease in tensile strength of starch film.When the degrees of substitution are below 0.025,the adhesion demonstrats a gradual increase,and it reaches the highest value at 0.025 and then gradually decreases.The elongation of CS film rose gradually but the strength reduced.The stabilities of the CS pastes are worsened as the degree of substitution is increased,but are higher than that of acid-converted corn starch paste.