Isotactic Polypropylene/Titanate Whisker Composites And Compatibilizing

Isotactic polypropylene?PP?is widely used with excellent mechanical properties and processability,but the poor impact property limits its further application.Titanate whiskers and multiwalled carbon nanotubes are suitable reinforcing and toughening agents for composites because of its excellent mechanical properties and versatility.The effect of surface modification of titanate whiskers and multiwalled carbon nanotubes and the selection of compatibilizers on the properties of polypropylene composites was studied by means of interface construction in this paper.The surface of titanate whiskers was coated with silica and treated with silane coupling agent?-aminopropyl triethoxysilane?KH550?.The modified whiskers were separately mixed with maleic anhydride grafted polypropylene?PP-g-MAH?,maleic anhydride grafted polyethylene?PE-g-MAH?,maleic anhydride grafted polyolefin elastomer?POE-g-MAH?and PP.The obtained samples were melt blended in different proportions to obtain double compatibilizers PP/titanate whiskers composites.The mechanical performance showed that the composites added PP-g-MAH and PE-g-MAH had the highest impact strength of 7.4±0.1 kJ/m².The impact strength of composites with POE-g-MAH and PP-g-MAH can be up to 9.9±0.7 kJ/m²,which was increased by about 139%and 220%respectively compared with PP.SEM observed that the addition of PP-g-MAH increased the bonding force between whiskers and PP,and the pulling effect was obvious after the addition of PE-g-MAH.The results of DSC and polarized light microscopy showed that the addition of PP-g-MAH promoted heterogeneous nucleation,while the addition of PE-g-MAH/POE-g-MAH inhibited heterogeneous nucleation.When the double compatibilizrs were used,?-form crystals were found.The whiskers and multiwalled carbon nanotubes compound fillers were obtained by using KH550.Mechanical results showed that adding compatibilizers PP-g-MAH and 5 wt%compound fillers,the tensile and impact strength of composites reached to 34.8±0.5 MPa and 6.3±0.3 kJ/m²respectively,the volume resistivity decreased to 9.0×10¹²?·cm,which was decreased by four orders of magnitude.The improvement of impact performance and the regulation of tensile and flexural properties for PP are of great significance for expanding its application field and improving its application value.