Synthesis And Evaluation Of PMA Type Pour Point Depressants For Diesel Fuels

As a widely used petrochemical energy,diesel plays a very important role in transportation and economic development.In low temperature environment,n-alkanes in diesel are easy to separate out and cross-linked to form a strong network structure,which can seriously affect the application of diesel.In this paper,a series of pour point depressants(PPD)were prepared with benzyl methacrylate as the main monomer for improving the low temperature fluidity of 0 # diesel.The mechanism of PPD was studied by polarizing microscope(POM),differential scanning calorimetry(DSC)and rheological test.The main research contents are as follows:(1)a series of copolymers(MB-R1 MC,R1 = C12,C14,C16 and C18)were prepared by polymerizing benzyl methacrylate(MB)and methacrylate(R1MC),and the effect of the length of carbon chain and monomer ratio in MB-C14 MC on the pour point reduction was explored.The experimental results show that as the ratio of MB-C14 MC was 1:10 and the addition concentration was 3000 ppm,the solid point(SP)and cold filter-plugging point(CFPP)of diesel were reduced by 26 ? and 12 ?,respectively.POM,DSC and rheological analysis were used to study the change of copolymers on the morphology,thermodynamic phase change and viscosity of diesel wax.(2)In order to further improve the depression effect of PPD,N-vinylpyrrolidone(NVP)was introduced into the MB-R1 MC to synthesize the terpolymers methacrylate-benzyl methacrylate-N-vinylpyrrolidone(R1MC-MB-NVP,R1 = C14 and C16).The effect of NVP in the terpolymers on the depression effect was studied by adjusting the ratio of the three monomers.The results show that C14MC-MB-NVP has a good effect on the SP,while C16MCMB-NVP is more conducive to reduce the CFPP.Combining the advantages of both,C14MCMB-NVP and C16MC-MB-NVP are mixed in different proportions to obtain a composite pour point depressant,which is superior to a single pour point depressant in both SP and CFPP.When C14MC-MB-NVP(5:1:1)and C16MC-MB-NVP(15:1:1)are mixed by 1:4,the effect is the best.When the addition concentration is 2000 ppm,the SP and CFPP are reduced by 29 ? and 15 ?,respectively.The DSC,POM and rheology are used to characterize them,it is found that the size of wax crystal becomes smaller,its dispersion is enhanced and the effect of pour point reduction is enhanced.