Synthesis Of A Nano-Composite Pour Point Depressant And Its Evaluation For Improving Low Temperature Performance Of Diesel Fuel

Diesel fuel contains large amounts of normal paraffins.In cold areas or low temperature conditions,these normal paraffins are easy to crystallize and precipitate,and form a three-dimensional network structure,thereby blocking the engine tubes and filters.Therefore,poor cold flow performance will undoubtedly become a major resistance to the effective use of diesel.The purpose of this study is to improve the low-temperature fluidity of diesel fuel,based on different methods to modify and synthesize different nano-SiO₂ particles,prepare and optimize efficient methacrylate polymers,and then synergize the two with nano-composite to obtain results The better nanocomposite diesel pour point depressant,using differential scanning calorimetry(DSC),polarized light microscope(POM),rheological test,and other detection methods to systematically discuss its mechanism of action.The main research contents are as follows:(1)Regular nano-SiO₂ particles were prepared by inverse microemulsion method,and for their extremely hydrophilic and oleophobic properties,different modifiers were used for organic modification.The agglomeration effect of nano-SiO₂ particles modified by polydimethylsiloxane(PDMS)was found to be the most obvious,and the nano-SiO₂ particles before and after modification were characterized by scanning electron microscope(SEM),Fourier transform infrared spectrometer(FT-IR)and thermogravimetric(TGA)analyzer.Using dodecane as a solvent,the compatibility and stability of modified nanoparticles in organic solutions were studied.The results show that PDMS has effectively modified the nano-SiO₂particles with lipophilicity.(2)Based on the previous work of the research group,different benzyl methacrylate-benzyl methacrylate copolymers(MB-R₁MC,R₁=C₁₂,C₁₄,C₁₆,C₁₈)were synthesized as diesel pour point depressants.In order to further improve its performance,different modified nano-SiO₂ obtained in(1)was used to obtain a nano-composite pour point depressant for different nano-SiO₂ and MB-R₁MC polymers by solvent blending method.Effect of MB-R₁MC pour point depressant on diesel cold flow performance.The results show that the nano-SiO₂/MB-C₁₄MC composite pour point depressant is better than the MB-C₁₄MC copolymer pour point depressant at the same dose.And the mass ratio of nano-SiO₂/MB-C₁₄MC is 1:6,when the addition amount is 3000 ppm,The cold filtration point and freezing point of diesel fuel are reduced by 16°C and 32°C respectively.In addition,the mechanism of action was explored by differential scanning calorimetry,polarizing microscope and rheological analysis.