Study On Surface Modification Of Talc Etc And PP Filled With Them

The main study includes: surface modification mechanism, technical and token of the inorganic fillers talc, CaCO3 and Wollastonite;effect of fillers on properties of filled PP composite. The surface modification of talc etc is treated by titanate, aluminate, borate and silane coupling agents, which testifies that content of different coupling agent exists an optimal range. The effect of modification is evaluated by a serious of methods, including contact angle, activation rate and absorption of DOP. For the modified fillers, contact angles to distilled water are increased markedly, absorptions of DOP are decreased, and activation rates are increased with the increased coupling agent content. The results show that the modification change the polarity of the surface of fillers, the surface change from hydrophilic to hydrophobic. PCM results reveal that modified fillers are mostly in primary or oligomic state, and the dispersion degree is improved. PSD curve shows a bigger grain size and lower specific surface area of modified fillers. In order to discuss modification mechanism, we study the unmodified, modified fillers and coupling agent by IR.The spectrograms of modified fillers distilled by acetone still show the character apices of coupling agents at 2850cm-1 and 2920cm-1, which indicates the chemical bond effect between coupling agents and fillers surface. Modified fillers can be more contributing, decrease of absorptions of DOP can reduce the immobility of plasticizing agent, so that decrease the cost.The modified powder of better effect is respectively added as fillers to blend PP matrix, then manufacture PP composite by melt extrude. Study the physical, mechanical and thermal properties, flow process property, moreover IR and PCM. The results show that rigid and heat-resistant of filled PP composite are improved;HDT is increased from 127℃ to 142℃, weightlessness is decreased by 41.2%. When the filler content is below 20wt%, MI of filled PP is increased, which means well flow and process properties;Coupling agent has plasticizing and lubricative effect, which is good to increase MI. IR spectrograms indicate the chemical bond effect between PP matrix and filler. PCM results reveal that modified filler can be distributed uniformly in the PP matrix, indicating the better compatibility between PP and filler, which finally determine the higher properties of the PP composite than that of untreated filled PP;charpy and izod notched impact strength change respectively from 25.22KJ/m2, 50.69 KJ/m2 to 28.18 KJ/m2 and 52.56 KJ/m2, tensile strength is increased from 33.93MPa to 36.43MPa. XRD curves reveal that all of fillers fillers have some nucleation effect, which can increase the crystallization degree of PP ,but not change the crystal type of PP matrix,nucleation of talc is the highest. Break appearance is studied by SEM, photos show that modified talc/PP exists yield and cut at the break, which means better toughness. Compared to study on PP composite filled with modified acerate Wollastonite and granular CaCO3, talc has better strengthened and toughened effect to PP composite, because of its Lamellar structure and high nucleation. The study is of importance to increase the additory value of talc and extend application of PP.