Research On Preparation And Properties Of Polypropylene Toughtened With Shear Thickening Fluid

Polypropylene (PP) is a kind of general plastic with good physical and processing properties. However, the application of PP is limited considerably due to its poor impact strength. Shear thickening fluid (STF) is a kind of non-Newtonian fluid, the apparent viscosity of which can change greatly under high shear rate. If the impact strength of PP could be improved by shear thickening effect of STF, it is possible to expand the range of application.Nano silicon dioxide (nano-SiO2) was used as the dispersed phase, and polypropylene glycol (PPG) was used as the dispersion medium. PPG-STF was prepared by dispersion nano-SiO2into PPG with a high shear emulsifying machine. The influence of nano-SiO2content and PPG category on the properties of PPG-STF was discussed. Then, PPG-STF toughened PP (PP/PPG-STF) was prepared via melt blending of PPG-STF with PP in an internal mixer. The mechanical properties, rheological properties and crystallization behavior of PP/PPG-STF were investigated. On the above basis, bamboo plastic composites, toughen by PPG-STF, were prepared through melt blending of PPG-STF with PP and bamboo fibre. The effect of PPG-STF and bamboo fibre content on the properties of bamboo plastic composites was studied.The experiment results showed that PPG400-STF has better shear thickening effect than PPG600-STF, while PPG600-STF has better toughening effect than PPG400-STF. PPG600-STF can lower the crystallization rate of PP and improve impact strength and processing flowability of PP/PPG-STF. Impact strength of PP-R/PPG-STF and PP-H/PPG-STF have been improved by3.8times. PPG600-STF can improve impact strength and processing flowability of bamboo plastic composites significantly.