核磁共振法研究原油降凝剂F21分子结构与性能之间关系

NMR STUDIES ON CHAIN STRUCTURE AND PROPERTIES OF TERPOLYMER POUR POINT DEPRESSANT F12 FOR CRUDE OIL

用核磁共振氢谱和碳谱研究了乙烯－醋酸乙烯酯三元共聚物型原油降凝剂Ｆ２１的分子结构与性能之间的关系。研究结果表明共聚物中醋酸乙烯酯含量和支化度对原油凝固点降低有很大影响，找出了使青海、高尚堡、渤海三种原油凝固点下降７－１４℃的最佳分子结构，发现乙烯平均序列长度为８．３即乙烯链段平均含１６．７个碳原子时，共聚物对原油的降凝效果最好。

F21,a commercially manufactured pour point(P.P.)depressant,is chemically an ethylene(E)/vinylacetate(V)/sodium allylsulfonate terpolymter with very low content of allylsulfonate and in these NMR studies is treated as E/V copolymer.The V content and branching index(BI)of 19 samples of F21 are determined by 1￣HNMR and the triad sequence distribution and E and V sequence lengths(L_E and L_v) of 6 F21 samples-by￣(13)CNMR techniques.It is shown that the F21 samples with MI<250,BI<3/100C in E sequence,V content 34-39%(m)and L_E 7-8.5(8.3 in average) have the best effect of depressing P.P.and reduce P. P.of crude oils of Qinhai (in 200 ppm)and of Gaoshangbao and Bohai (in 100 ppm) by 8-14℃.