Preparation Of Polypropylene/Laponite Composites

Polypropylene (PP) is one of five common plastics,with low prices,a wide sourceof raw materials,easy processing characteristics,rapid development in recent years,inmany industries have been widely applied.But PP have shortcomings such as the largeshrinkage rate,low temperature brittleness,so focus on the development of PPmodified PP industry.After mixed with the elastomer PP blend can greatly improvethe toughness of the composite material,but also can reduce the strength of theblend.While elastomers and rigid particles modified PP can rise and enhancetoughening effect.Compared to EPDM and other traditional elastomer,polyolefinelastomer (POE) such as a better weather resistance,the advantages of bettercompatibility with PP,can under the low filling PP brittle ductile transition occurs,when is the present study more elastomer.Nano silicate clay because of its large lengthto diameter ratio,good dispersion and adsorption,widely applies in the middle of themodified PP,montmorillonite, mica is used more silicate clay,etc.Laponite is asynthetic clay,with a sheet of uniform diameter,dispersion,etc.,have been found forpolyamide-based hydrogels have better enhanced toughening effect.This work wasprepared by the PP/Laponite binary complex materials and PP/POE/Laponite ternarycomposites and tested the relative performance of the specific work follows:(1)Three different organic modifiers on Laponite surface treated.IR spectroscopy,thermal gravimetric analysis test showed lipophilic and hydrophilic organicmodifier success of Laponite were modified,changing the surface polarity ofLaponite.(2)Maleic anhydride grafted polypropylene (PP-g-MAH),as a compatibilizer forpreparing PP/Laponite compound material,and tested the relative performance and thedispersion of Laponite in PP matrix.After adding the organic Laponite,flexuralmodulus and flexural strength of the composite has significantly improved,organicLaponite3#in an amount of3wt%,PP-g-MAH in an amount of2wt%bendingstrength is36.5MPa,compared to pure PP increased by38%;bending modulus is1289MPa compared to pure PP increased by50%;tensile strength is24.6MPacompared to pure PP increased by15%;filling Laponite lead the impact strength of the composites became lower;SEM tests found after treatment Laponite has improvedsignificantly in the PP matrix dispersion,binding,dispersed particle size of about0.5um, laponite untreated in PP dispersed particle size of approximately1.5~2um.(3)PP/POE/Laponite ternary composites were prepared by melt blending.Twoorders were used to prepare the composites.Direct extrusion was called method1#;use internal mix to blend Laponite and POE first then use extruder to blend thecomposite with PP is called method2#.The performance and the dispersion ofLaponite and POE in the PP matrix were tested.POE phase in an amount of15wt%when prepared by the method2#PP/POE/Laponite ternary composite lowtemperature impact strength than that of pure PP and PP/POE binary composites wereincreased3.5fold and2.5fold;SEM images show that the method2#ternarycomposite materials,Laponite and POE formed of POE wrapped Laponite"core-shell"structure,which was prepared by the method1#among the ternary compositematerials, Laponite and POE independent decentralized and PP matrix.