Research And Application Of Epdm Functionalied By Maleic Anhydride And Triallyl Isocyanurate

In this paper,the melt grafting modification of maleic anhydride(MAH)and triallyl isocyanurate(TAIC)on the ethylene propylene diene monomer(EPDM)was studied,and the effects of various factors on the grafting reaction were discussed.The results showed that the grafting ratio of MAH could be significantly improved by using TAIC as co-graft monomer.It was found that the copolymerization of TAIC and MAH played an important role in the grafting reaction.The grafting reaction was carried out by using dicumyl peroxide(DCP)as a initiator,and the results showed that TAIC had higher activity than MAH,which was firstly grafted with EPDM radical to form EPDM-TAIC·,and then the radical was grafted with TAIC or MAH.When the content of TAIC was increased from 0phr to 0.8phr(3.2×10-3mol),the grafting rate of MAH was obviously increased.However,the further increase of TAIC content would lead to the increase of crosslinking degree and the increase of gel ratio,which is not conducive to the graft copolymerization.When MAH content was not more than 5phr(5×10-3mol),MAH was mainly cografted with TAIC.Meanwhile,when TAIC is more than 1.2phr,the TAIC structure is the main component in the grafted chain or the cross-linking network structure.The effects of various reaction factors on the grafting reaction was studied to get the optimum formula,which was that EPDM was 100 phr,MAH was 5phr,TAIC was 0.8phr and DCP was 0.15phr;the optimum process conditions were that temperature was 180?,reaction time was 8min and rotor speed was 75r/min.The grafting rate of EPDM-g-MAH/TAIC was the highest under this condition.Meanwhile,compared to the effects of DCP and BPO on the grafting reaction,it was found that the effect of DCP was better than that of BPO.In order to investigate the regularity of copolymerization of MAH and TAIC,the MAH-TAIC copolymer was prepared by precipitation polymerization in the experiment and the structure of the copolymer was analyzed by means of nuclear magnetic resonance(NMR),etc.The effects of various reaction factors on the conversion rate,particle morphology,number-average molecular weight(Mn)and distribution of copolymer were analyzed to get the optimum conditions,which was that reaction temperature was 80?,the reaction time was 4h,the dosage of BPO was 5% and the molar ratio of MAH to TAIC was 1:1.Under these conditions,the surface of the copolymer microspheres was smooth,the particle size was uniform and the conversion rate of copolymer was the highest,which is 35.92%.The number average molecular weight of the copolymer was low,ranging from 1800 to 4000,and the molecular weight distribution(MWD)was between 1.5 and 2.5.So the results showed that the extent of polymerization of MAH and TAIC was weak,and oligomers were produced under high initiator concentration.The toughening modification of polypropylene(PP)by EPDM-g-MAH/TAIC(G-EPDM),whose grafting rate of MAH was 0.6%,and EPDM respectively was studied.The results showed that The notched impact strength of EPDM/PP blends was 6 times higher than that of PP when the ratio of EPDM or G-EPDM to PP was 25/75,while Notched impact strength of G-EPDM/PP blends was improved by about 11 times,which was obviously better than that of EPDM,and the dispersion of G-EPDM in the PP was more uniform and the particle size of G-EPDM was smaller.