Investigate of physical, thermal and morphological study of Phragmites australis flour/nanoclay/ polypropylene oxide

Background and objectives: Wood plastic composite that briefly (WPC) called are a new class of composite materials that in recent years have been the attention of many researchers and a major part of the industry. For improve some properties of wood plastic composite, various nanoparticles was used that one of them is clay that due to the high specific surface and mineral source, improves properties of nanocomposite. Therefore this study with aim to investigation the effect of nanoclay and polypropylene oxide coupling agent (OPP) on Phragmites australis flour/waste polypropylene was done.
Materials and methods: For this purpose first polypropylene was oxidized in molding phase and in the presence of atmospheric oxygen and alcohol. Then Phragmites australis flour and polypropylene with were mixed weight ratio of 50% in internal mixer. Nanoclay to 3 levels 0, 2 and 4% and coupling agent to 2 levels 0 and 3% were used. Test boards were made using a hot press. Physical properties such as long-term water absorption and thickness swelling, humidity coefficient diffusion and thickness swelling rate, thermal properties such as thermal analysis (TGA) and morphological properties such as X-ray diffraction (XRD), the field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) were done. To ensure the oxidation of polypropylene as well as infrared spectroscopy (FTIR) were used.
Results: The results showed that the long-term water absorption and thickness swelling, humidity coefficient diffusion and thickness swelling rate were decreased with increasing of nanoclay and coupling agent (OPP),. Thermal properties of nanocomposite improved with increasing of nanoclay and coupling agent. The result of field emission scanning electron microscopy (SEM) showed that by addition of coupling agent, the interface between two phases' lignocellulosic fiber and polymeric matrix improvement. The result of X-ray diffraction (XRD) showed that with increasing of nanoclay to 2%, the distance between the silicate layers of clay increased but by addition 4T nanoclay, the distance between the silicate layers slightly decreased and type in nanocomposite structure is intercalation. The transmission electron microscopy (TEM) as well as approved this. The result of infrared spectroscopy (FTIR) indicates the oxidation of polypropylene in the presence of oxygen.
Conclusion: As a general conclusion can be said that the use of nanoclay and compatibility oxidized polypropylene (OPP), improved properties of Phragmites australis flour/polypropylene nanocomposite. Therefore, the use of 2% nanoclay (for cost-effectiveness) with 3% OPP for the manufacture of composites with desirable features is recommended. K