Competition between Physical Cross-Linking and Phase Transition Temperature in Blends Based on Poly(N-isopropylacrylamide-co-N-ethylacrylamide) Copolymers and Carboxymethyl Cellulose Articles uri icon

publication date

  • July 2020

start page

  • 2000081-1

end page

  • 2000081-10

issue

  • 14

volume

  • 221

International Standard Serial Number (ISSN)

  • 1521-3935

Electronic International Standard Serial Number (EISSN)

  • 1022-1352

abstract

  • The combination of thermoresponsive polymers and biopolymers is growing due to the multiple benefits, owing to their tunable properties. Numerous works focus on the preparation of materials by chemical cross-linking, but physical cross-linking (based on hydrogen bonding) has not been deeply studied. In this context, questions around the hydrogen bonding of physical-crosslinking and lower critical solution temperature (LCST) need to be addressed, especially when a second comonomer is incorporated. This study is based on the preparation of blends of poly(N-isopropylacrylamide-co-N-ethylacrylamide) copolymers and carboxymethyl cellulose (CMC) by dis-solution, where the LCST-transition and physical-crosslinking are studied. The results show a strong eect of the comonomer on the properties in compar-ison with the CMC, especially for solutions of methanol/water. Low contents of N-ethylacrylamide (NEAM) can promote physical-crosslinking and the gela-tion, avoiding cononsolvency observed for homopolymers. On the other hand, NEAM will disrupt the gelation when the comonomer content is high enough.

keywords

  • blends; carboxymethyl cellulose; lower critical solution temperature; physical cross‐linking; thermoresponsive copolymers