Amphiphilic Block Copolymers with Vinyl Caprolactam as Kinetic Gas Hydrate Inhibitors

Macrosurfactants consisting of water-soluble poly(vinylcaprolactam) (PVCap) or poly(vinylpyrrolidone) (PVP) segments with comparatively shorter hydrophobic poly(styrene) (PS) poly(2,3,4,5,6-pentafluorostyrene) (PPFS) were used as kinetic hydrate inhibitors (KHIs). These synthesized 2-cyanopropan-2-yl N-methyl-N-(pyridin-4-yl)dithiocarbamate switchable reversible addition–fragmentation chain transfer (RAFT) agent at 60 °C 90 for 1-P(S/PFS) 1-PVCap, respectively, followed by extension 70 PVCap PVP, respectively. The addition to the pure methane-water system resulted in a 53% reduction methane consumption (comparable PVP 51% inhibition) during initial growth phase. A PS-PVCap block copolymer comprised 10 mol% PS and improved inhibition 56% compared no KHIs. Substituting more PPFS segment further 73%. By increasing ratio PS- PVCap- groups polymer, an increase its potential was measured. For PPFS-PVCap, from 5% 10% decreased formation rate 6%. However, PPFS-PVCap copolymers than 20 unable dissolve water due hydrophobicity attendant low critical micelle concentration (CMC).