摘要
以Ziegler-Natta催化剂TiCl4/Al(i-Bu)3为催化体系,己烯、辛烯、癸烯和十二烯4种长链α-烯烃为聚合单体,制备得到超高相对分子质量聚烯烃减阻剂,考察了聚合反应条件对聚合物相对分子质量的影响,以及单体侧链长度对聚合物结晶性和减阻性能的影响。得到的最佳聚合反应条件为:主催化剂Ti Cl4浓度为5.2×10^–4 mol/L,聚合单体与环己烷体积比为1∶1,反应时间至少为1440 min,此时,聚合产物重均相对分子质量达到3.50×10^6;通过13CNMR对聚合物进行分子结构表征,证明聚合完全且为目标产物;DSC曲线和XRD谱图表明,随着聚烯烃侧链长度的增加,聚合物结晶性增强,影响聚合物减阻剂溶解性。采用旋转圆盘测试方法表征了聚合物减阻率,结果表明,在相同相对分子质量条件下,随着聚合物的侧链长度增加,减阻率明显提高。
Four kinds of long-chain α-olefins, including hexene, octene, decene and dodecene were selected as monomers in the homopolymerization catalyzed by TiCl4/Al(i-Bu)3 to prepare polyolefin drag reducing agents with ultra high relative molecular weight. The effects of polymerization conditions on the relative molecular weight of the polymers were investigated. The effect of the side chain length of the monomers on the crystallinity and drag reduction performance of the polymer were also discussed. The optimum polymerization conditions were obtained as follows: molar concentration of TiCl4 as main catalyst 5.2×10^–4 mol/L, volume ratio of monomer to cyclohexane 1∶1, and reaction time at least 1440 min. Under these conditions, the relative molecular weight of the polymers was higher than 3.50×10^6. 13 CNMR results indicated that the polymerization was completed and the resultant homopolymers were consistent with the target product. DSC and XRD measurements showed that with the increase of side chain length of polyolefin, the crystallinity of polymer increased, which affected the solubility of polymer drag reducer. The rotating disk system was used to test the polymer drag reduction rate. The results revealed that the drag reduction rate tended to increase with the increase of the side chain length of the drag reduction agent when their relative molecular weights were the same.
作者
李东城
李隆伟
唐萍
赵巍
王海
宾月珍
LI Dongcheng;LI Longwei;TANG Ping;ZHAO Wei;WANG Hai;BIN Yuezhen(School of Chemical Engineering,Dalian University of Technology,Dalian 116024,Liaoning,China;Sinopec Dalian Research Institute of Petroleum and Petrochemicals,Dalian 116045,Liaoning,China)
出处
《精细化工》
EI
CAS
CSCD
北大核心
2020年第5期1045-1050,共6页
Fine Chemicals
基金
中国石化科技发展项目(318022-5)。
