Study On Properties Of Organic Montmorillonite/Polypropylene Nanocomposites

PP act as one of the five general plastics which with a wide range of sources of raw materials,low price,excellent heat resistance and mechanical properties had been widely used in automotive,electronics,packaging and building materials,furniture and other fields.However,numerous challenges,including large shrinkage-rate,brittleness under low temperature and poor wear resistance etc.,still need to be overcome.In order to improve the toughness and processing performance of PP,the PP/POE/β-NA and PP/PSM/OMMT/β-NA composite were studied respectively in this paper.The details are as follows:（1）PP/POE/β-NA composite system: mechanical properties and SEM showed that when the content of POE was 25% and the amount of β-NA was 0.1%,the impact strength of composites was up to 80.9 kJ/m² and and the fracture toughness of the material was obvious.POE can increase the surface energy of the materials,improve the thermal stability of the materials,and reduce the heat resistance of the materials.The testing of melting flow rate showed that POE can make the processing fluidity of the material worse;The rheological properties show that POE can make the complex viscosity η*,the storage modulus G’ and the loss modulus G" increased,the loss factor δ decreased.Melt crystallization behavior analysis:POM and WAXD results showed that the addition of POE can accelerate the crystallization rate and inhibit the crystallization of PP.β-NA can improve the crystallization rate and refine the grain of PP.The kinetics of isothermal crystallization showed that with the increase of the number of melting times,PP matrix trans from α-PP to β-PP,the crystallization rate of the composites was significantly faster than pure PP,and this phenomenon is more obvious at high temperatures.（2）PP/PSM/OMMT/β-NA composite system: FTIR results showed that MAH and ST were successfully grafted onto the POE molecular chain,the MAH on the PMS hydrolysis with water adsorbed by OMMT during the melting intercalation process.The generated—COOH has a strong interaction with OMMT surfaces.Mechanical properties and SEM showed that he impact strength of composites was up to 86.5 kJ/m² and the toughness fracture features of composites tensile fracture surface is obvious by incorporating 30% POE,0.2%β-NA,3% OMMT into PP martix.Both PSM and OMMT can improve the smoothness,thermal stability and heat resistance of the material;The addition of OMMT can increase theMFR and of decreas the Dr of material;The rheological properties show that PSM can ncrease the complex viscosity η*,the storage modulus G’ and the loss modulus G"of the material,but the loss factor δ decreases.Melting-crystallization behavior analysis: the results of POM and SAXD show that the addition of OMMT can make us obtained an intercalation composite material and PSM can expand the OMMT layer spacing.The kinetics of isothermal crystallization shows that with the increase of the number of melting times,the melting range of P₆₇PSM₃₀OM₃β-NA_0.2 was increased,the Tm of β-PP increased and the Xc decreased slightly,the crystallization rate of P₆₇PSM₃₀OM₃β-NA_0.2 was significantly higher than pure PP,and this phenomenon is more obvious at high temperatures.