Componental Analysis and Characterization of Some Common Pour Point Depressants Used Domestically and Abroad

Aiming to find the effect of components of pour point depressants (PPD′s) on their properties, various analytical methods, including IRS, gel chromatography, super-conducting NMRS, saponification titration and GC-MS, were applied to the componental analysis of 10 samples of home-made and imported PPD′s commonly used for diesel oil. It was found that all of the 10 PPD′s were belonged to the type of polymers of ethylene-vinyl acetate, with relatively low relative molecular mass (Mr<5 500). Contents of polymers of vinyl acetate in the samples were found in the range of (w) 27%-37%. Heavy aromatic hydrocarbons mainly of C10 or their mixtures were used as solvents for the PPD′s. The following differences were found between the domestic and imported samples: ① higher Mr (Mr>3 700) and higher polymer contents (over 30%) for the imported PPD′s; ② small amounts of N-containing dispersing agent were found in the imported products.