Study On The Compatibility Of PA6/PP Blend

polypropylene(PP) was modified by melt grafting copolymerization with a crylic acid(AA), using styrene(St) as the co-monomer. Effects of several factor s such as concentrations of monomer (AA), co-monomer(St) and initiator(DCP) on grafting reaction were investigated. The grafted polymer was identified by FTIR. Thermal stability and crystal performance of the grafted polymers were characterized by TGA, WAXD and DSC.Two different series of grafted polymers were used as compatibilizers top repare PA6/PP blends by melt extruding. One are self-made polymers grafted with acrylic acid the grafting degree of which is approximately 1.8%, includi ng PP-g-AASt, PE-g-AA and EPDM-g-AA. The other are purchased polymers grafted with maleic anhydride the grafting degree of which is about 1%, cons isting of PE1-g-MAH, PE2-g-MAH and PE-g-MAH. Diverse effects such as Categories of Compatibilizer (different grafting matrix or diverse grafting mon omers), concentration of compatibilizers, blending ratio of PA6/PP,PP matrix(h omopolymer or copolymer) on the mechanical property(static or dynamic stat e),crystallization perform, rheological behavior and microstructure were investi gated.The following conclusions can be drawn from the paper:(1) In the grafting polymerization process, the grafting degree raise first thendeclined as the concentration of DCP, AA or St increased.(2) As the grafting degree increased, T₅₀, T₁₀₀ and T_mv increased first, then maintained for a while and diminished finally. (3) AA and St were chiefly grafted onto the surface of PP, the origina 1 crystal model was not influenced, few amount of AA was propitious to thenucleation of PP and enhancement of crystallization.(4) when concentration of EPDM-g-AA, PE1-g-MAH or PE2-g-MAH w ere as great as 18wt%, the impact strength of PA6/PP blend was significantly increased.(5) As far as PA6/homopolymerized PP blend was concerned, EPDM-g-AA was a more effective Compatibilizer for the alloy then PE-g-AA making i t a condition that the concentration of the Compatibilizer was the same . Wh en it came to PA6/copolymerized PP blend, the differences between the comp atibilization effect of EPDM-g-AA on the blend and that of PE-g-AA were ne gligible conditioned that the Compatibilizer concentration fixed.(6)The self-made PP-g-AASt could fairly improve the dispersing of PP in the PA6 matrix when the concentration was very low(2%). Of all the com patibilizers used in this paper, PP-g-AAst was the most effective in increasing the tensile strength of alloy.(7) As the concentration of PA6 increased in the blend, the tensile and flexural strength increased incessantly. But there existed an optimum impact st rength. The blending ratio of PA6/PP varied when the best impact property w as gained for each compatibilizer.(8) when the concentration of the compatibilizer was the same, the com patibilization effect of EPDM-g-AA on the PA6/homopolymerized PP was not different from that of PE-g-AA on the PA6/copolymerized PP. Circumstances weredifferent for PE-g-AA. The compatibility of PA6/PE-g-AA/ copolymerized PP was superior to that of PA6/PE-g-AA/ hopolymerized PP.(9) The addition of compatibilizers had no effect on the melt behavior of PP but had considerable effect on the melt behavior of PA6. The addition of compatibilizer resulted in the double peak of PA6 in the DSC melting test.(10) As the concentration of the compatibilizer increased, the melt visco sity enlarged. On condition that the concentration of the compatibilizer fixed, the melt viscosity increased as the concentration of PA6 raised in the blend.