| HDPE can be used to packing film,cable,pipe and so on.Because of its linear structure of polyethylene chain,HDPE has poor temperature resistance,and the softening point of VEKA is 120 ?.Moreover,HDPE is a non-polar polymer,its tolerance to organic solvents is poor.Therefore,HDPE has higher requirements for heat resistance and solvent resistance.In this paper,heat resistance and solvent resistance of HDPE were improved through technology modulation and formulation design.And the influences of PA6 and different compatibilizers on the performance of PE pipes at different grades were discussed.Secondly,the effect of organic montmorillonite on the performance of HDPE/PA6 was studied.The following conclusions are obtained:(1)The three compatibilizers coulld effectively increase the PE/PA6 blends.However,because of compatibilization and its own performance,the properties of the blends were slightly different.We had found that the best compatibilizer was compatibilizer 305 and the second is compatibilizer 493.(2)Under the same PA6 dosage and compatibilizer condition,PE 100 had higher mechanical properties,solvent resistance and heat resistance than PE80.The influence of PA6 and compatibilizer on the thickness of PE80 wafer was very small,which had great influence on the crystallinity.The heat resistance and solvent resistance of the blends basically obeyed the trend of increasing first and then decreasing with the increase of PA6 dosage.(3)The research on heat resistance and solvent resistance of the extruder screw speed showed that when the rotational speed was at 180r/min,the heat resistance and solvent resistance were the best.(4)The effect of the addition order on the montmorillonite modified blends showed that the blends prepared by one step method show smaller size of dispersed phase and exhibit better tearing resistance.The blends prepared by the two step method were better in heat resistance and solvent resistance.(5)The effect of modified montmorillonite with different affinity on the properties of the blends was different,the modified effect of DK5 was better than that of DK4,and 305 and DK5 collaborative modification effect was best.When 0.6%DK5 was added,the performance was the best,the Vicat softening point temperature increased by 2.3 ?,the heat distortion temperature increased by 6.5 ?,the resistance to benzene swelling decreased by 1.4%,and the resistance to crude oil swelling decreased by 0.17%.(6)A new type of organic montmorillonite was prepared,and its D001 was 1.47nm,which increased 0.28nm compared with the original soil.It was found that the spacing of the modified montmorillonite has a great influence on the intercalation of the montmorillonite in the polymer,and the montmorillonite had a tendency to selectively distribute in PA6 and form intercalation or even peeling state. |
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