交联淀粉对剪切增稠胶流变性能的影响

Influence of crosslinked starch on rheological property of STG

为提高剪切增稠胶(STG)的抗冲击与阻尼性能,以交联淀粉(CS)、STG为主要原料制备CS-STG。采用X射线能谱仪(EDS)、X射线光电子能谱仪(XPS)、偏光显微镜(PM)、扫描电子显微镜(SEM)和旋转流变仪分析考量了CS-STG的化学成分、微观结构、流变性能,探究了CS对STG流变性能的影响。结果表明,CS-STG样品表面C、O、Si元素均匀分布,含量与STG相近;加热过程中CS与STG反应生成Si—O—C键,极大地增强受力时应力传播的范围;交联反应能保护淀粉在制备CS-STG时不被高温破坏;CS与STG两相相容性较好,未发生微观相分离;CS-STG的剪切增稠效果及耗能能力均强于目前常用的CaCO_(3)和SiO_(2)无机颗粒,其中在STG中添加CS(质量分数为50%)的样品在大振荡模式下能量耗散为STG的1549%,剪切模量达到STG的2835%。

In order to improve the impact resistance and damping properties of shear thickening gel(STG),CS-STG was prepared with crosslinked starch(CS)and STG as the main raw materials.X-ray energy-dispersion spectroscopy(EDS),X-ray photoelectron spectroscopy(XPS),polarizing microscope(PM),scanning electron microscope(SEM)and rotational rheometer were used to analyze the chemical composition,microstructure,rheological properties of CS-STG,explored the influence of CS on the rheological properties of STG.The results shown that the C,O,and Si elements on the surface of the CS-STG sample were evenly distributed,and the content was similar to that of STG.During the heating process,CS reacted with STG to form Si—O—C bonds,which greatly enhanced the range of stress propagation under force.The crosslinking reaction can protect starch from being damaged by high temperature during the preparation of CS-STG.CS and STG had good compatibility and no phase separation occurd.The shear thickening effect and energy consumption of CS-STG were stronger than the commonly used inorganic particles of CaCO_(3) and SiO_(2).Among them,the sample with CS(50% mass fraction)added to the STG dissipated the energy of STG 1549% in the large oscillation mode,the shear modulus reached 2835% of STG.