Research On Multi-impregnating Agents Assisted Grafting Modification Of Polypropylene

Polypropylene(PP)is a widely used general purpose plastics,due to its high strength,low density,good heat resistance,easy processing and low cost and so on.But because of the linear chain structure of polypropylene,low activation energy on the surface,leading to its poor hydrophilic and antistatic properties,poor dyeability and printing,and poor compatibility with synthetic polar polymers,these disadvantages limit the further application of PP in many areas.This study used Impregnation-Solid method,the polar groups grafted to the PP long chain to improving properties of PP.Impregnation-Solid grafting modification is divided into two steps:(1)using the multi-Impregnating agents swelling polypropylene,the grafted monomer,initiator transfer into the PP base;(2)recycling Impregnating agent 1,Impregnating agent 2 used as interface agents,free radicals coused by heat,and then get solid-phase grafting reaction product.Using BPO as initiator,single monomer(MAH),bimonomer(MAH/St)and ternary-monomer(MAH/St/BA)were grafted onto PP in the solid state with assistant of impregnant.The effects of impregnant species,impregnant dosage,swelling time,swelling temperature,reaction conditions,initiator dosage and monomers were investigated in details.The results show that the best reaction condtions of Impregnation-solid pahse grafting are as follows:Impregnating agent 1 dosage 10mL,Impregnating agent 2 dosage 1.25mL,impregnated swelling time 10h,impregnated swelling temperature 27?,reaction temperature 100?,stirring rate 120r/min,w(BPO):w(PP)=0.35%,PP dosage 10g,particle size 60 mesh-80 mesh,two monomer ratio w(St):w(MAH)=1.1:1,three monomer ratio w(BA):w(St):w(MAH)=4.1:1.1:1,Get the highest grafting percentage and grafting efficiency.The products were characterized by FTIR,contact angle measurement and Melt flow rate which shows that monomers were grafted onto the PP backbone and the polarity of the products was increased.Analysis results indicated that combination of soft monomer and hard monomer can counteract decreasing of mechanics properties caused by introducing side-chains and Impregnation-solid graft to achieve internal graft and graft uniform.