Study On The Ramie Fiber Modified With Amino Silicone Oil And The Ramie Fiber/PP Composites For Automobile Interior

Natural fiber reinforced polypropylene composites is a new type of automotive interior materials. In recent years, these materials have attracted lots of attention. Natural fiber is a kind of promising materials which can implace the glass fiber and carbon fiber as the reinforcement meet the requirements of light and environmental friendly in automobile industry.Ramie fibers is a natural materials.It can be effectively solve the energy sources crisis for automobile industry due to its light weight, good mechanical properties, low price, recyclable and environmental friendly features, wide range of sources and so on. However, due to the ramie fiber’s surface containing a large number of hydroxyl, the interfacial adhesion of the ramie fiber and resin matrix is not good enough, thus it affects the overall performance of the composite materials. Therefore, to improve the performance of the composite materials, it is necessary to modify the surface properties of ramie fiber, reduce the hydrophilicity of ramie fiber and improve the interface compatibility of the ramie fiber and matrix resin.In this thesis, amino silicone oil was used to modify ramie fibers, and the modification had improved the interface compatibility of the ramie fiber and matrix resin. Techniques, such as infrared ray (IR), contact angle measurement, X-ray diffraction (XRD), thermogravimetric analysis(TG) and scanning electron microscopy(SEM), were employed to study the structure and properties of ramie fiber. The results showed that after modification, the amino silicone has grafted onto the surface of ramie fiber surface. Modification has reduced the hydrophilicity of ramie fiber, increased crystallinity and thermal property of ramie fiber, reduced the impurities of ramie fiber significantly, these changes will benefit the bonding strength between fiber and PP.In this work, the impact of modification on the properties of the modified ramie fiber reinforced PP composites was studied. The results showed that the optimal temperature for modification is 80℃. After modification, the performance of composite materials are improved significantly, among them, the tensile strength is increased by 20.08%, the bending strength by 17.81%, the impact toughness by 39.39%, the elongation rate by 38.77%,respectively. The thermal property is also improved significantly. SEM analysis indicated that modification had improved the interfacial compatibility of ramie fiber and polypropylene resin significantly.In this thesis, the effectt of fiber content on the properties of the composites was also studied. The results showed that the tensile strength and bending strength were apparently improved with the increase of fiber content. Anyway, while the impact strength and elongation behaviors decreased with the increase of fiber addition. The optimization value of fiber content is of 30wt%. The maximal tensile strenrth, bendingl strength and impact strength is 28.66MPa,35.83Mpa, and 7.77KJ/m2, respectively. The mechanical properties of the modified ramie fiber reinforced PP composites meet the requirements of automotive interior materials.