Preparation And Characterization Of Maleic Anhydride Grafted Polypropylene With High Grafting Rate

In this paper,polypropylene(PP)graft maleic anhydride(MAH)copolymer(PP-g-MAH)containing polar functional groups was prepared by melt grafting in order to obtain high graft ratio PP grafting,reduce the residue of MAH in PP and inhibit the degradation of polypropylene.Firstly,from the analysis of the low grafting ratio of MAH in the graft copolymer,the way to improve the grafting rate of PP-g-MAH is proposed.The structure of the graft prepared by the laboratory was simply analyzed by infrared(FT-IR),Gel chromatography(GPC),Differential Scanning Calorimetry(DSC).Then,the reasons for the low grafting rate of the grafts under the conventional conditions are analyzed,and the means of modification are proposed from the reasons.Three aspects of increasing monomer concentration,monomer dispersion and inhibiting polymer degradation were studied and the effect of three aspects on the grafting rate of graft copolymers were discussed.In order to continue to increase the grafting rate of MAH,the reaction system using epoxidized soybean oil as solvent and styrene as the second monomer was studied in this paper in detail.The detailed structure of the isolated side chains was characterized by Nuclear Magnetic Resonance Spectroscopy(1H-NMR),DSC,GPC to illustrate the reasons for the increase of grafting rate.Then,the effects of temperature,rotation speed,initiator dosage and other variables on the grafting rate of PP-g-MAH/St graft were studied.Finally,the paper studied the reaction system with PP as the matrix and asmall amount of polyethylene(PE)and silica(Si O2).It is discussed that PE and Si O2 greatly promote the grafting of MAH.The structure of the copolymer graft was analyzed by grafting rate(GD%),FT-IR,1H-NMR,GPC,Scanning Electron Microscopy(SEM)and torque variation.The grafting position and the reaction mechanism of addition of polyethylene and silica grafts were analyzed,and the corresponding viewpoints was proposed.