乙烯/1-十二烯共聚物的制备及减阻性能评价

PREPARATION AND PERFORMANCE STUDY OF DRAG REDUCTION POLYMER BY ETHYLENE/DODECENE COPOLYMERIZATION

采用溶液聚合法,以TiCl4/MgCl2为主催化剂、Al(i-Bu)3为助催化剂、乙烯和1-十二烯为聚合单体、正己烷为溶剂,制备了二元聚合物减阻剂。室内环道减阻性能评价结果表明,在1L反应釜内,1-十二烯和正己烷总体积为600mL、聚合温度为-2℃时,最优共聚条件为主催化剂用量0.4g、n(Al)/n(Ti)=80、V(1-十二烯)/V(正己烷)=2/3、m(1-十二烯)/m(乙烯)=912,合成的聚合物减阻率为45.45%。采用13 C-NMR、XRD对聚合物结构和结晶度进行表征,结果表明,乙烯单体的引入使聚合物的结晶度明显降低,有助于提高减阻剂在油品中的有效浓度,降低减阻剂溶液的用量。

Using ethylene and dodecene as polymerization monomers,a drag reduction copolymer of ethylene？dodecene was synthesized by solvent polymerization with n-hexane as a solvent. The composite TiCl4？MgCl2 was used as a main catalyst and Al（i-Bu）3 as a cocatalyst. The structure and crystalinity of the copolymer produced were characterized by 13 C-NMR and XRD techniques. The drag reduction per-formance of copolymer was evaluated in a self-designed indoor loop evaluation system with 1L reactor containing 600 mL mixture of dodecene and n-hexane at -2 ℃. Under the optimum polymerization con-ditions：0.4 g main catalyst,n （Al）？n （Ti）of 80,V （dodecene）？V （n-hexane）of 2？3,m （dodecene）？ m（ethylene）of 912,the drag reduction rate is 45.45%. Compared with dodecene homopolymer,the crystallinity of the copolymer of ethylene？dodecene is significantly decreased due to the participation of ethylene,which helps to improve effective concentration of the copolymer in the oil,and to reduce the amount of drag reduction solution.