| The blends could obtain excellent synthetical properties from blending of polypropylene and high molecular polymer. The way which blended PP and PA6 to obtain composite was convenient. The PP/PA6 composite could overcome weaknesses of materials and improve the performance of materials efficiently. The PP/PA6/SMA composite which had good synthetical properties was prepared by two screw extruder, with PP and PA6 as raw materials,the different types of grafted PP as compatilizers, and SMA as toughener.First of all, three types of grafted PP(PP-g-(MAH-St)、PP-g-(MAH-BMA)and PP-g-(MAH-St-BMA)) were prepared by melt bleding, with MAH as the principal monomer,BMA and St as the co-monomers. The effect of grafting was characterized by contact angle.The factors that affect contact angle of grafted PP were studied respectively, such as screw speed, dosage of initiator, molar ratio of different monomers and dosage of monomer. The properties of grafted PP were investigated by the test of melt flow rate, viscosity average molecular weight and gel fraction. The products were also characterized by Fourier infrared spectroscopic analysis. The results showed that the optimum conditions to prepare PP-g-(MAH-St)as follows: screw speed was 160?r/min, the melt temperature was 170?℃, dosage of initiator was 0.05%, dosage of MAH was 3.0%, and the molar ratio of BMA and MAH is1:1. Other conditions being equal, The optimum conditions to prepare PP-g-(MAH-St)as follows: dosage of MAH was 4.0%, the molar ratio of St and MAH was 1:1; the optimum conditions to prepare PP-g-(MAH-St-BMA)as follows: dosage of MAH was 3.0%, the molar ratio of MAH, BMA and St was: 2:2:2. The PP-g-(MAH-BMA)had the minimum contact angle and best synthetical properties, and gel fraction was zero.Secondly, To improve the strength and toughness of material, the PP/PA6 and PP/PA6/SMA composites were prepared by melting extrusion with the three types grafted PP as compatilizers, and the self-made SMA as toughener. The effects of PP’s content, category and content of initiator on mechanical properties of the system were investigated. The other properties of composites were investigated by test of melt flow rate and vicat softening point,etc. The composites were also characterized by differential scanning calorimetery and TG.Experiments showed that PP-g-( MAH-BMA) had the best compatibilization among different grafted PP. When content of PP-g-(MAH-BMA) was 9%, inventory rating of PA6 was 20%, the tensile strength and flexural strength of the PP/PA6 composite reached41.02?MPa and 59.92?MPa respectively, which were increased by 11.2% and 36% than pure PP respectively. But the impact strength and break elongation of PP/PA6 composite was decreased. When the dosage of SMA which put into the PP/PA6 composites was 1%, the impact strength of PP/SMA/PA6 composite was increased efficiently, and other mechanical properties were also maintain good level. The flexural strength, tensile strength and impact strength of the composites were 57.0?MPa、39.39?MPa and 6.96?kJ/m2 respectively, which were increased by 32.6% 、11.2%、48.7% than pure polypropylene respectively. The addition of polyamide 6 and SMA could improve the surface hydrophilicity of PP, and heat-resistant of composite was also increased. The main type of crystal of PP in composite was α crystal,in addition, the crystallizing points of PP/PA6 and PP/SMA/PA6 composite were higher than pure polypropylene. |
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