Bo Yao

Influences of different functional groups on the performance of polyoctadecyl acrylate pour point depressant

ABSTRACT The polyoctadecyl acrylate (POA), polyoctadecyl acrylate-vinyl acetate (POA-VA), polyoctadecyl acrylate-maleic anhydride (POA-MA), and polyoctadecyl acrylate-styrene (POA-St) were synthesized and used as pour point depressants (PPDs). The performance of the PPDs first increases with the increase of polar group (MA or VA) content, and then decreases with the further increase of polar group (MA or VA) content. The POA-VA PPDs show the best performance at the OA:VA molar ratio 3:1, whereas the POA-MA PPDs shows the best performance at the OA:MA molar ratio 7:1. The performance of POA-St PPDs decreases outstandingly with the increase of the nonpolar St molar fraction.

Effective flow improving agents for waxy crude oil

ABSTRACT The comb-like copolymer-polyhedral oligomeric silsesquioxane (POSS) nano-composite PPDs, including POA-POSS, POA-VA-POSS, POA-MA-POSS and POA-St-POSS, were first synthesized via in-situ reversible addition-fragmentation chain transfer (RAFT) polymerization and characterized by FT-IR, NMR and TGA methods. Subsequently, the effects of the nanocomposite PPDs on rheology of a waxy crude oil were studied. Results showed that POA-VA-POSS is the most efficient PPD among the nanocomposite PPDs, which can depress the pour point, gelation point, apparent viscosity and yield stress of the crude oil to the lowest. Associated with the microstructure of crude oil, the rheo-logical improving mechanisms of the copolymer-POSS nanocomposite PPDs are discussed.