This invention discloses a BN@EVA composite
pour point depressant and its preparation method, belonging to the
petrochemical field. The invention improves the compatibility of nano-
hexagonal boron nitride (BN) with
ethylene-
vinyl acetate copolymer (EVA) by
hydroxylation and
amination, and then uses a
solvent blending method to composite BN-NH2 and EVA in
xylene to prepare the BN@EVA
pour point depressant. The
mass fraction of BN in the composite
pour point depressant is 1-3 wt%, with an optimal value of 2 wt%. When the addition amount is 500 mg / kg, the pour point of
crude oil can be significantly reduced from 19℃ to -7℃, a reduction of 26℃. FT-IR and SEM characterization confirmed that BN was successfully modified and uniformly dispersed in the EVA matrix; DSC curves showed a decrease in
crystallization temperature and a bimodal synergistic effect;
microscopic observation showed that the
wax crystal morphology changed from a dense network to a dispersed spherical shape, effectively improving low-temperature fluidity. This invention has the advantages of good pour point depressant effect, simple process, and low cost, and is suitable for the extraction and pipeline transportation of high-
wax crude oil.