| In this paper,the effects of high melt strength polypropylene,random copolymer polypropylene,toughening agent and low density polyethylene on the properties of injection-grade micro-foamed polypropylene were studied in 20% talc filling system.The results show that PP can have good foaming properties by blending with other polymers.High melt strength Polypropylene,random copolymer polypropylene can significantly improve the foaming properties and pore state of the material.The addition of ethylene-octyl copolymer(POE)and low density polyethylene(LDPE)can increase the melt strength of the material and improve the foaming performance.High melt strength polypropylene(HMSPP)was prepared by grafting modification and adding inorganic particles(wollastonite)in twin screw extruder.The flexural strength,tensile strength,impact strength and fracture tensile strain of HMSPP prepared by different methods were studied and compared.The varieties of polypropylene(PP),the amount of foaming agent,the types of nucleating agent and PP/LDPE blends were also investigated.The effect of the ratio on the apparent density and morphology of the material was investigated by scanning electron microscopy(SEM).The results show that high melt strength polypropylene material can be obtained by adding inorganic particles wollastonite and grafting modification.The modification effect of wollastonite is better than that of grafting modification,and the impact strength of grafting modification material is improved obviously.The foaming ratio increases with the increase of the amount of foaming agent.When the amount of foaming agent,AC and NC is 1 phr,1 phr and 1.5 phr respectively,the comprehensive performance of LDPE foaming material is better.The melt strength of homopolypropylene can be improved.When the dosage of PP-C2,T30 S and LDPE is 55 phr,30 phr and 15 phr respectively,the foaming effect of the material is better.The addition of nucleating agent is beneficial to PP foaming,and the effect of talc powder is better than that of calcium carbonate and sodium benzoate.SEM observation showed that the foamed rods prepared with talc powder as nucleating agent had denser and more uniform cellular structure.The effects of inorganic fillers on gloss and dimensional stability of high gloss polypropylene are discussed emphatically.The test results show that barium sulfate has the least effect on the luster of the material,and talc has the greatest influence on the luster.Talc powder contributes the most to improving the shrinkage and stable size of polypropylene material after mold,and barium sulfate is equivalent to calcium carbonate.Differential thermal calorimeter(DSC)data verify the effect of crystallization temperature.This paper adopted double screw extruder melt extrusion granulation process polypropylene mineral composite materials was prepared and studied the kind and amount of boric acid ester coupling agent on the properties of polypropylene mineral composite materials,focus on the bending strength,tensile strength,impact strength and melt mass flow rate,and the impact section morphology was characterized by SEM,and through the DSC curve and TGA data on the crystallization behavior of PP composite materials and heat resistant properties were characterized.The results show that the mica and talc powder as a filler can improve the mechanical properties and decrease shrinkage of PP composites,boric acid ester coupling agent treatment after mineral filler,can obviously improve the impact of the composite material properties and melt flow rate,improve the crystallization property of the material,improve the heat-resistant decomposition property,and improve the interface bonding between the matrix and the filler.boric acid ester coupling agent modification effects of HL-80 is better,boric acid ester coupling agent for filler dosage of 2%,comprehensive performance is best. |
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