Study On Melt Grafting Of Maleic Anhydride Onto Ethylene-propylene Copolymers

In this paper, EPM-g-MAH and EPDM-g-MAH were prepared with Maleicanhydride (MAH) as the monomer by multi-monomer melt grafting technology inthe Haake mixer. The effects of a series of factors such as MAH content, initiatortypes and content, reaction temperature, rotor speed, reaction time, a secondmonomer Styrene(St) content, the anti-crosslinking agent content and types on thegrafting ratio(GR) and gel ratio were studied as well as tested by FTIR. At the sametime, the mechanical properties of peel strength and tensile strength were tested, toget the best recipe and process conditions.In the EPM-g-MAH system, results indicated that Dicumyl peroxide(DCP) wasthe more appropriate initiator than Benzoyl peroxide(BPO), and optimal content ofMAH was3.0g and DCP content was0.22g given EPM content100g when optimumprocess parameters were that temperature was170℃, rotor speed was60r/min andreaction time was8min. In this case, the highest GR was about0.46wt%. The GRincreased to0.69wt%when the mole ratio of St and MAH was1:1, which obviouslyimproved the GR of the grafting products. The better anti-crosslinking agent wasN,N-dimethylaniline(DMBA), which the highest GR could increase to1.15%whenthe DMBA content was0.02wt%. The results also revealed that the DMBA couldreduce the crosslink degree in the grafting progress of EPM as well as the gel ratio.Studies of EPDM-g-MAH showed that DCP was also the better initiator, and optimalcontent of MAH was about2.9g and DCP content was about0.22g at the condition of EPDM content about100g， while optimal process parameters were thattemperature was about169℃, rotor speed was60r/min and reaction time was8min.In this case, the highest GR was about0.77wt%. Based on above recipe and processcondition, the GR increased to0.87wt%when a second monomer St was added andthe mole ratio of St and MAH was1:1. What’s more, the GR was improved to1.12wt%when the DMBA content was0.02wt%.The peel strength and tensile strength were tested on the grafting products. Theability of adhesion with metal was improved obviously in the results, so improvedthe compatibility of Ethylene-propylene rubber(EPR) with other materials. At thesame time, the same trend was showed by compatibility and grafting ratio, the bettercompatibility was improved, the higher grafting ratio was.The EPM, EPM-g-MAH with different GD and Polyamide6(PA6) blends wereprepared in the twin-screw extruder and the mechanical properties were investigated,in order to improve the toughness property of PA6. The results showed that theeffects of the EPM-g-MAH on the toughness of PA6was obviously superior to EPM.On the other hand, the stronger impact strength was improved, the higher graftingdegree was. At the meantime, the decreasing degree of other mechanical propertiessuch as tensile strength, flexural strength was smaller. When the GD of EPM-g-MAHwas1.10wt%, the impact strength was improved by10times than pure PA6. On thebasis, the impact strength of blends was compared by different products ofLANSESS and the EPM-g-MAH with different GD toughening of PA6respectively.And to get a good toughening effect, the GD of the grafted copolymers was neededto improve.