The Study Of The Properties Of Fly Ash Filled Polypropylene Composite

It is an important study direction for the high value-added use of fly ash. The fly ash was used to fill the polypropylene (PP), which not only can improve the properties of the composite material, but also can reduce the cost of material.After being modified by coupling agent, the scattered effect of the fly ash was improved distinctly and the modified effect of silane coupling agent was better than of titanate coupling agent. There were still characteristic peak of the coupling agent on the surface of the modified fly ash after being filtrated by the acetone, which explains that there was the chemistry linkage between the coupling agent and the fly ash. Coupling agent DB-550 and DB-792 can coat the surface of the fly ash evenly, but the coupling agent HC-TTS appeared the uneven phenomenon.The study of mechanical properties showed that, after being modified by the coupling agent, the best filled size reduces from 160-180 items to 200-300 items and the best filled quantity of modified fly ash increases from15% to 25%, which show that the coupling agent can improve the interface contact between PP and fly ash effectively. At the same time, the best amount of coupling agent is 1% of the fly ash.The study of rheological properties showed that, with the increase of the temperature and shear rate, the shear viscosity of PP and fly ash/PP composite material was decreased. The smaller the particle size of the fly ash was, the lower the shear viscosity of the composite material was. When the quantity of the fly ash was filled to 15%, the shear viscosity of the composite material was low. When the amount of the coupling agent was 1%, the shear viscosity of the composite material was high. When the filled quantity of modified fly ash was 25%, the liquidity of the composite material is also better.The study of scanning electron microscope showed that because the non- modified fly ash can not scatter very well, the composite material appeared stress concentration and cracking phenomenon. After being modified, the combination of fly ash and PP is quite close and the structure of tensile section is rich, the drawing phenomenon is obvious. Filling the fly ash makes the melting peak of composite material shift to the low temperature direction. With the increase of the modified fly ash quantity, the melting peak of composite material had the trend to high temperature direction. A small quantity of fly ash can play a role in the heterogeneous nucleation, but increasing the filled quantity can change the crystallization form of PP. The complex wide Si-O peak appeared in the infrared spectra of complex systems and the characteristic peak of PP weakened or even disappeared significantly, which show that the chemistry linkage had taken place between the modified fly ash and the PP.In short, after being modified by coupling agent, the fly ash could replace part of the PP, without lowering the properties of the PP, reduce the cost of PP products at the same time.