Study On Modified Polypropylene Blend System By Ionomers

Polypropylene is one of the most widely used synthetic materials because of its excellent performance,such as high tensile strength,and excellent chemical resistance.However,the lack of poor toughness and non-polarity limits the application of polypropylene.To improve the properties of polypropylene,it can be blended with PA11 or imidazolium-based elastomeric ionomers(ionically modified brominated Poly(isobutylene-co-isoprene)(i-BIIR),and the polypropylene ionomer is used as a compatibilizer to improve the compatibility of the blends.The propylene/11-iodo-1-undecene(PP/IUD)copolymers were synthesized by dimethyl(pyridylamino)hafnium catalyst and it was taken as intermediates and the iodine group underwent a nucleophilic substitution reaction with N-methylimidazole to prepare N-methylimidazole isotactic polypropylene ionomer(IA).Isotactic polypropylene(iPP)and bio-renewable polyamide 11(PA11)were mixed with the isotactic polypropylene ionomers to prepare novel polymer blends with excellent physical properties.As observed,dispersed phase(PA11)particles size was significantly reduced from about 20?m to 1?m in iPP/PA11/ionomer ternary blends.Accordingly,notched impact strength of the iPP/PA11/ionomer(70/30/5)ternary blends was greatly improved from 2.11 kJ/m~2 to 6.73 kJ/m~2 without significantly sacrificing of tensile strength.Polypropylene(iPP)and bio-renewable polyamide 11(PA11)were mixed with N-methylimidazole polypropylene ionomer and o-mercaptoaniline hydrochloride polypropylene ionomer(IB),respectively.The DMA and SEM analysis results showed that the compatibility of the iPP/PA11 blends was improved;the notch impact tests showed that impact strength of iPP/PA11/IA(70/30/5)increased significantly compared to iPP/PA11/IB(70/30/5).Imidazolium-based elastomeric ionomers(i-BIIR)with different alkyl chain imidazole were synthesized and explored as novel toughening agents for i PP by melt blending,and the polypropylene ionomer was used as a compatibilizer to improve the compatibility of the blends.With the i-BIIR content increasing,the tensile strength of the blends gradually decreased,and the impact strength increased gradually.The impact strength of the i PP/i-BIIR-4/IA(80/20/5)ternary blend reached 36.20 kJ/m~2,which was about 13 times that of iPP.In summary,the morphology and mechanical behavior of the iPP/PA11 blends and iPP/i-BIIR blends were studied,which were compatibilzed with polypropylene ionomer.And the miscibility of the blends was significantly improved.The thesis provides a method to improve the compatibility of PP/PA and PP/i-BIIR blends.