Design of a rigid side chain for poly(N-vinylamide) derivatives bearing an alkenyl group and evaluation of their ability to inhibit tetrahydrofuran hydrate crystal growth

Kinetic hydrate inhibitors (KHIs) are water-soluble polymers that are used to prevent gas hydrate formation in flow lines during upstream oil and gas production. All commercial polymers have pendant hydrophobic moieties with saturated carbon-carbon bonds. In our previous studies, poly(N-vinylamide) derivatives bearing the alkyl groups and the ethylene glycol groups were synthesized and investigated as KHIs. Compared with our previous studies, we have now synthesized poly(N-vinylamide) derivatives in which the alkenyl group has been introduced at the N-position to improve the rigidity and steric hindrance of the side chain. The KHI performances of synthesized polymers were evaluated by the method of THF hydrate crystal growth. The inhibition ability of THF hydrate crystal growth was dependent on the molecular weight of synthesized polymers. Higher molecular weight polymers, above 4000 g/mol, tend to show higher inhibition efficiencies compared with lower molecular weight polymers, around 1000 g/mol. However, the KHI performance of poly(N-vinylamide) derivatives bearing the alkenyl groups was generally lower than the polymers of the previous studies. This indicates that the side chain rigidity and/or steric hindrance do not significantly influence the KHI performance.

This is the peer reviewed version of the following article: Ryo Kawatani, Malcolm A. Kelland, Hiroharu Ajiro, Journal of Applied Polymer Science. 2020, 137, 38, 49154., which has been published in final form at https://doi.org/10.1002/app.49154. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited.