Preparation And Impact Resistance Of Carbon-based Modified Shear Thickening Composites

With the rapid development of protection technology,the demand for impact resistance and light weight of materials has become more rigid.Due to the prominent advantages of shear thickening materials,and they have become a new type of lightweight impact cushioning material.Traditional shear thickening materials can be classified into two types of materials,namely,shear thickening fluid（STF）and shear thickening glue（STG）.Among them,shear thickening glue has gradually become a research hot spot of high-quality shock-resistant cushioning materials due to its good application prospects for high-speed impact resistance and buffer energy absorption.This article aims to improve the high-speed impact resistance and buffering energy absorption performance of STG materials,by selecting the reaction system of hydroxy silicone oil and boric acid,carbon-based（graphene,carbon fiber）as functional modified fillers,and blends to prepare GO-STG and SCFs-GO-STG composite materials.The study successfully established the influence of GO and SCFs on the impact resistance and cushioning energy absorption properties of STG materials,and further reveal the impact of GO and SCFs mixed with STG materials Damage mechanism,via systematically study the quasi-static compression behavior and dynamic compression behavior of the two types of materials.The dispersion method and dispersion process of GO in the dispersion system were determined through the development of the solvent blending method.The synthesis and preparation process route and method of GO-STG composite materials were formulated,while GO-STG composite materials with different GO contents were prepared.GO-STG composite was characterized through SEM-EDS,TEM and other microscopic equipment.The results indicated that GO is uniformly dispersed in the GO-STG composite at a scale of 200 nm～300nm.In addition,the addition of GO is beneficial to improve the thermal performance of STG materials.The GO-STG composite material was tested and analyzed for creep,rheology,static compression,and dynamic compression under different strain rates.The analysis found that the addition of GO can significantly improve the creep resistance and shear increase of GO-STG composites.Dynamic compression increases the strength by 3 to 4 orders of magnitude,compared to static compression under low strain rate.The study determined that when the GO content is 0.25 wt.%,the impact resistance of the composite material is the best,specifically,the yield strength reaches 32.2 MPa,and the unit volume absorption energy reaches 8.25 MJ/m³.The nano-scale lamella GO can bridge the linear STG molecular chain in the matrix STG and increase the bonding opportunity of the B:O dynamic bond.In addition,the rigid GO can also carry and transfer stress,thereby improving the GO-STG composite The impact resistance of the material.The addition of SCFs in GO-STG composites can further improve the thermal performance and impact resistance of the material with the optimized impact resistance when SCFs is 6 wt.%.The maximum yield strength is 64.2 MPa,the elastic modulus reaches 280.76MPa at a strain rate of 3600 s^-1.Meanwhile,it has high energy absorption characteristics,and the kinetic energy absorbed per unit volume reaches 19.4 MJ/m³.Compared with the GO0.25-STG composite material without SCFs,the elastic modulus of SCFs6-GO-STG composite material is increased by 2.2 times,and the energy absorption per unit volume is increased by60%,which is compared with the energy absorption per unit volume of the matrix STG material with an increase of 106%.It can be seen that the fiber and the matrix interface are well bonded,and more energy is dissipated when the fiber is pulled out which gives the SCFs-GO-STG composite good impact resistance,through the analysis of the microscopic morphology of the broken section.