摘要
Well-defined polypropylene grafted silica nanoparticles(PP-g-SiO_(2))were prepared through the reaction of maleic anhydride grafted polypropylene(PP-g-MAH)with amino-functionalized silica(SiO_(2)-NH_(2))by the'grafting-to'method.The grafting density of PP-g-SiO_(2) is found to be controlled by the concentration of silane coupling agent 3-[2-(2-aminoethylamino)ethyl amino]propyl trimethoxy silane(TAMS).The maximum grafting density of grafted PP-g-MAH chains with molecular weight of 9100 g/mol could reach 0.34 chains/nm~2,when the critical concentration of TAMS was 0.0194 mol/L.The critical concentration of TAMS can be explained by the maximum amounts of primary amino groups,which can totally react with PP-g-MAH on the surface of SiO_(2)-NH_(2),when the silane monolayer is formed.The synthesized PP-g-SiO_(2)with different molecular weights was mixed with PP by solution mixing to form a series of nanocomposites.The crystallization temperature(T_(c))of nanocomposites increased significantly with the particle loading.The PP-g-SiO_(2) with high molecular weight of grafted chains exhibits a high nucleation ability at 1 wt%nanoparticle loading in PP/PP-g-SiO_(2)nanocomposites.In summary,we provide an effective method to synthesize the well-defined PP-g-SiO_(2)with controlled grafting density,which shows excellent nucleation ability.
基金
financially supported by the National Natural Science Foundation of China(No.51820105005)
the Ministry of Science and Technology of China(No.2017YFE0117800)。