High throughput synthesis and characterization of PNIPAM-based kinetic hydrate inhibitors

Abstract

� 2016 Libraries of kinetic hydrate inhibitors (KHIs) based on poly(N-isopropylacrylamide) (PNIPAM) were synthesized by post-synthetic modification of an existing PNIPAM copolymer. Unlike other synthetic routes this generates accurately controlled libraries of KHIs with similar molecular weight (M?w), molecular weight distribution, end groups and composition. This allows for accurate interpretation of the effect of each of these components and highlights key functional groups that can improve performance. This was assessed using a high throughput KHI ranking method based on its inhibition performance of Structure II (sII) forming cyclopentane (c-C5) hydrate under atmospheric pressure. Hydrate inhibition tests showed that performance of PNIPAM-based KHIs can be improved by careful inclusion of select groups. In addition, cloud point data demonstrates that polymers with higher deposition points could be generated using this method. The presence of side products has a pronounced effect on cloud point but minimal effect on hydrate inhibition performance. These data provide valuable insights into polymers that can improve the performance of KHIs. The method can also be applied to a number of structural motifs to develop chemicals to overcome issues associated with natural gas transport.