Preparation And Functionalization Of Gasoline Olefin Copolymer By Self-stabilized Precipitation Polymerization

With the increasingly stringent standards of automobile gasoline in our country,it is imperative to reduce the olefin content in gasoline.Although conventional refining technologies can improve the quality of gasoline,the problem of low utilization efficiency of olefin resource still exists.In order to improve the added value of olefins,this paper directly used gasoline waste olefins and maleic anhydride（MAH）as raw materials to prepare anhydride functionalized copolymers by green and efficient self-stabilized precipitation polymerization（2SP）.The quality of gasoline was effectively improved,and meanwhile realizing the resource utilization of mixed olefins in gasoline.In this paper,owing to the high reactivity of the anhydride group,the gasoline olefin-MAH copolymer was further chemically modified through imidation and N-hydroxymethylation.Finally,functional copolymer with active hydroxymethyl groups was successfully prepared,and the reaction conditions were optimized.The main research of this paper is as follows:1.Due to the complex composition of mixed olefins in gasoline,which is not conducive to the quantitative study of high-value modification,1-Pentene-maleimide model copolymer（PPMI）with 61.4%yield and 73.2%mass fraction of imide structural units in the copolymer was prepared by 2SP polymerization using 1-pentene as the model monomer in this part.The effects of PPMI concentration,formaldehyde/maleimide molar ratio,alkali catalyst amount and temperature on the N-hydroxymethylation reaction were investigated in detail,and the modification conditions were optimized.The experimental results showed that when the PPMI concentration was 10 wt%,the amount of alkali catalyst was 0.1 wt%,the formaldehyde/imide molar ratio was 1/1 and the reaction was carried out at 40°C for 2 h,the modified product could reach a high degree of N-hydroxymethylation.2.Gasoline olefin-MAH copolymer microspheres（POMs）were prepared by 2SP polymerization using mixed olefins in gasoline as raw materials.The effects of different reaction media on the yield,monomer conversion,surface morphology and particle size of the as-prepared POMs copolymer microspheres were systematically investigated.The experimental results showed that ethyl acetate/cyclohexane mixture was the most suitable reaction medium for the preparation of POMs microspheres by 2SP polymerization.When the mass percentage of EA in the reaction medium was 60.0 wt%,the morphology of produced POMs microspheres was regular,the surface was smooth,the size was homogeneous,the average particle size was about 1300nm,and the polydispersity coefficient was 1.02.3.Gasoline olefin-MAH cross-linked copolymer microspheres（POMBs）were prepared by 2SP polymerization,and POMs and POMBs microspheres were treated with ammonia and heated at 160°C for 12 h to produce imide-modified POMI and POMIBs.N-hydroxymethylation modification was carried out under the above optimal reaction conditions,and POMI-N-CH₂OH with a large amount of active hydroxymethyl side group and cross-linked POMIBs@N-CH₂OH with surface active hydroxymethyl groups were successfully prepared.Moreover,the resultant POMIBs@N-CH₂OH maintained their original spherical shape and the particle size was 792 nm.