Production of polyalfaolefin-based lubricants using new (poly)ionic liquid /AlCl3 catalysts as environmentally friendly alternatives to commercial AlCl3 route

Abstract

Aiming to decrease corrosive AlCl3 dosage in polyalphaolefin production, two new (poly)ionic liquid /AlCl3 catalysts were synthesized from the reaction of 1-vinylimidazole with benzyl chloride (to yield IL) and subsequent polymerization of its vinyl bond by radical route, to achieve polyionic liquid (PIL). Cationic oligomerization of three α-olefin monomers, from 1-hexene to 1-decene, was accomplished using IL(or PIL)/AlCl3 catalysts with 50:50 wt.% composition to halve the usage of hazardous AlCl3. Microstructure and flow characteristic of the obtained PAO oligomers were characterized by 1HNMR, 13CNMR, GPC, viscometry, GC-Mass, and SimDis analyses and compared with those of PAOs from neat AlCl3. Results from GPC, viscometry and GC revealed that molecular weight decreases using lighter α-olefin monomers. Notably, while the PAOs from IL/AlCl3 have almost heavier fractions, the ones from PIL/AlCl3 and neat AlCl3 demonstrated similar molecular weight and KV100 amounts. The PAOs from PIL/AlCl3 and IL/AlCl3 represented a more uniform structures, with low short chain branching, beneficial to higher viscosity index (VI). This achievement featured PIL/AlCl3 as a suitable alternative to corrosive AlCl3, which besides its more environmentally friendly character, thanks to PIL presence, is capable of producing PAOs with the same KV100, however, with much higher VI values.