The synthesis of ultra-high molecular weight poly(1-hexene)s by low-temperature Ziegler-Natta precipitation polymerization in fluorous reaction media. (14th March 2018)

• Record Type: Journal Article
• Authors: Nifant'ev, Ilya E.; Shlyakhtin, Andrey V.; Tavtorkin, Alexander N.; Korchagina, Sofia A.; Chinova, Maria S.; Vinogradov, Alexey A.; Vinogradov, Alexander A.; Roznyatovsky, Vitaly A.; Khaidapova, Dolgor D.; Ivchenko, Pavel V.
• Is Part Of: Polymer. Volume 139(2018)
• Page Start: 98
• Page End: 106
• Publication Date: 2018-03-14
• Subjects: Polyolefins -- Drag reducing agents -- Precipitation polymerisation; Polymers -- Periodicals; Polymerization -- Periodicals; Polymères -- Périodiques; Polymérisation -- Périodiques; 547.7
• DOI: 10.1016/j.polymer.2018.02.011
• Languages: English
• ISSNs: 0032-3861

Abstract

Abstract: An effective method of 1-hexene polymerization in fluorous reaction media has been developed. When using perfluorinated compounds (FCs) as a solvent, the process, catalyzed by highly active titanium-magnesium catalysts modified with 3, 3-bis(methoxymethyl)pentane (BMMP) as an electron-donor, proceeds as a precipitation polymerization, and the reaction products represent highly stereo- and regioregular poly(1-hexene)s in the form of microparticles. In freons, polymerization can be carried out at sub-zero temperatures with monomer conversion up to 50% within 1 h and the formation of UHMW poly(1-hexene)s with Mn ∼2·10 6 Da. The polymers prepared in FCs demonstrate a high drag reducing effect (up to 40% in n -heptane for 0.25 ppm concentration), exceeding the previously described UHMW poly(1-hexene)s. Polymerization products after mixing with rapeseed oil form stable dispersions of ready-to-use drag reducing agents (DRAs) for pipeline oil transportation. Graphical abstract: Highlights: Precipitation polymerization of 1-hexene in freons at sub-zero temperatures. Highly stereo- and regioregular UHMW poly(1-hexene)s. Obtained polymers are ready-to-use dispersions with good morphology. Up to 40% drag reducing at 0.25 ppm polymer concentration.