剪切增稠胶/碳酸钙复合材料的制备及其抗冲击性能研究

为了提升人体防护装备的轻便性和灵活性,以剪切增稠胶(STG)为基体,并用纳米CaCO₃对其进行补强,制备了缓冲吸能性能优异的剪切增稠STG/CaCO₃复合材料,研究了CaCO₃含量和粒径对STG剪切增稠性能的影响。结果表明:添加CaCO₃后复合材料的最大储能模量比未添加时增加455%;添加的CaCO₃粒径越小,复合材料的剪切增稠性能越优异。通过落锤冲击实验表征了复合材料的抗冲击性能,CaCO₃的填充可使复合材料在具有最小变形量的情况下吸收更多的冲击力。探究了STG剪切增稠和CaCO₃补强的作用机理,指出剪切增稠现象是由交联键的形成和分子链的缠结作用产生的,CaCO₃通过吸能阻裂,分散冲击力产生补强作用。

Preparation and impact resistance of STG/CaCO3 composite

In order to improve the portability and flexibility of protective equipment,a shear thickened gel(STG)/CaCO₃ composite material with excellent buffering and energy absorption performance was prepared by using STG as matrix and reinforced by nano-CaCO₃.The effect of CaCO₃ addition and particle size on the shear thickening performance of STG was studied.The results shown that the maximum energy storage modulus(G′max)of the material after CaCO₃ addition was 4.55 times higher than that without CaCO₃.The smaller the particle size of CaCO₃ addition was,the better the shear thickening performance of the material will be.The impact resistance of the material was characterized through the impact test with a drop hammer.CaCO₃ could make the material absorb more impact force with the minimum deformation.The mechanism of shear thickening of STG was investigated,and it was pointed out that the effect of shear thickening was caused by the synergistic effect of the formation of crosslinking bonds and the entanglement of molecular chains.CaCO₃ generated reinforcement by preventing cracks,absorbing energy and dispersing impact force.