Study On The Preparation And Properties Of PA6/Inorganic Salt Composites

In this thesis,with the polymer-metal coordination principle,nylon 6(PA6)/metal salts complex composites were prepared by melt blending with different metal salts(such as magnesium salt,calcium salt and zinc salt)and PA6,and the composites structure and performance were studied.PA6/MgSO4-xH2O(x<1)composites,PA6/MgSO4 Composites and PA6/MgC2O4 composites were prepared by melt blending of magnesium sulfate heptahydrate(MgSO4·7H2O),magnesium sulfate(MgSO4)and magnesium oxalate(MgC2O4)into PA6.The results of optical microscopy showed that the three kinds of magnesium salts[MgSO4·xH2O(x<1),MgSO4 and MgC2O4]were dispersed uniformly in the matrix and the particle size was close.Gel permeation chromatography(GPC)analysis showed that the molecular weight of the three composites were close to the pure PA6 and without significant degradation;Differential scanning calorimetry(DSC)and polarized light microscopy(POM)showed that the three magnesium salts can play the role of heterogeneous nucleation and improve the parameters such as glass transition temperature,crystallinity,enthalpy of enthalpy and other parameters;Scanning electron microscopy(SEM)of impact fracture surface results show that the order of the compatibility of three kinds of fillers and matrix were MgC2O4,MgSO4·xH2O(x<1)and MgSO4;The mechanical properties show that,with the increase of the amount of magnesium salt,the tensile yield strength of PA6/magnesium salt composites increased from fast to slow were PA6/MgC2O4 composites,PA6/MgSO4·xH2O(x<1)composites and PA6/MgSO4 composites;Infrared spectroscopy(FT-IR)results show that three kinds of magnesium salts can coordinate with PA6,and MgC2O4 had the most obvious coordination effect.The PA6/CaSO4·xH2O(x<1)composites,PA6/CaSO4 Composites,PA6/CaC2O4 composites were prepared by melt blending of calcium sulfate dehydrate(CaSO4·2H2O),calcium sulfate(CaSO4)and calcium oxalate(CaC2O4)into PA6.The results of optical microscopy showed that the three kinds of calcium salts were dispersed uniformly in the matrix and the particle size was close;GPC analysis showed that the molecular weight of PA6/CaSO4·xH2O(x<1)composites and PA6/CaSO4 composites was similar to the pure PA6,But the molecular weight of PA6/CaC2O4 composites had the downward trend;DSC and POM results show that the three kinds of calcium salts can play the role of heterogeneous nucleation,and improve the PA6 crystallinity,melting enthalpy and other parameters;The SEM of impact fracture surface results show that the compatibility of three kinds of fillers and matrix were close;The mechanical properties show that,with the increase of the amount of calcium salt,the tensile yield strength of PA6/calcium salt composites increased from fast to slow were PA6/CaC2O4 composites,PA6/CaSO4·xH2O(x<1)composites and PA6/CaSO4 composites;FT-IR results show that three kinds of calcium salts can coordinate with PA6,and CaC2O4 had the most obvious coordination effect.The PA6/ZnSO4·xH2O(x<1)composites,PA6/ZnSO4 composites and PA6/ZnC2O4 Composites were prepared by melt blending of zinc sulfate heptahydrate(ZnSO4·7H2O),zinc sulfate(ZnSO4)and zinc oxalate(ZnC2O4)into PA6.The results of optical microscopy showed that the three kinds of zinc salts were dispersed uniformly in the matrix and the particle size was close;GPC analysis showed that the molecular weight of the three composites had decreased to some extent,and the reduce of the molecular weight of PA6/ZnSO4·xH2O(x<1)composites was the most obvious;DSC and POM results show that the three kinds of zinc salts can play the role of heterogeneous nucleation,and improve the PA6 crystallinity and melting enthalpy and other parameters;The SEM of impact fracture surface results show that the order of the compatibility of three kinds of fillers and matrix were ZnC2O4,ZnSO4·xH2O(x<1)and ZnSO4;The mechanical properties show that,with the increase of the amount of zinc salts,the tensile yield strength of PA6/zinc salts composites increased from fast to slow were PA6/ZnC2O4 composites,PA6/ZnSO4·xH2O(x<1)composites and PA6/ZnSO4 composites;FT-IR results show that three kinds of zinc salts can coordinate with PA6,and ZnC2O4 had the most obvious coordination effect.The results show that magnesium salt,calcium salt and zinc salt can coordinate with PA6,but the coordination ability between different forms of metal salts(such as the salt contain crystal water,the salt without water and oxalic acid metal salts)and PA6 is different,Thus affect the overall performance of composite materials.