体积拉伸流场作用下PP/纳米TiO_2共混物的热学及力学性能研究

Study on Thermal and Mechanical Properties of PP/Nano-titania Blends at the Function of Elongational Flow

通过新型叶片密炼机对聚丙烯(PP)/纳米二氧化钛(TiO_2)熔融塑化共混,获得PP/纳米TiO_2共混物。研究在拉伸流场作用下,不同纳米TiO_2含量和不同叶片密炼机转速对共混物热学和力学性能的影响。结果表明,拉伸流场作用下,共混物的冲击强度、拉伸强度和断裂伸长率随着纳米TiO_2含量呈现先增加后减少的趋势,纳米TiO_2含量为6%时,共混物冲击强度最高;纳米TiO_2含量为2%时,共混物拉伸强度和断裂伸长率最高。在转速较低时,转速变化对共混物力学性能影响不大,转速较高时,共混物力学性能有较大幅度的下降。纳米TiO_2含量和叶片密炼机的转速对PP/纳米TiO_2共混物的熔融和结晶行为的影响并不明显,PP/纳米TiO_2共混物的热稳定性随着纳米TiO_2含量的增加呈现先提高后降低的趋势,转速对于PP/纳米TiO_2共混物的热稳定性并不明显。

Polypropylene （PP） /nano-titania （nano-TiO2） blends were melt blended and acquired by novel vane mixer. The effect of nano-TiO2 content and rotating speed on the thermaland mechanical properties of the Blends at the function of elongational flow was studied. The results show that： with increasing nano- TiO2content, the impact strength, tensile strength and elongation at break increase firstly and then decrease. When the nano-TiO2 content is 6%, the impact strength of the blends reaches the maximum. When the nano- TiO2 content is 2%, the tensile strength and elongation at break of the blends reach the maximum. When the rotor speed is low, the mechanical properties of the blends change a little. When the rotor speed is low, the mechanical properties of the blends decrease significantly. The nano-TiO2 content and rotor speed show little influence on the crystalline and melting behaviors of the blends. With increasing nano-TiO2 content, the heat stability of the blends increases firstly and then decreases slightly. The rotor speed show little influence on the heat stability of the blends.