Polymer
Polymer
4 years ago

Dual thermoresponsive homopolypeptide with LCST-type linkages and UCST-type pendants: Synthesis, characterization, and thermoresponsive properties

Dual thermoresponsive homopolypeptide with LCST-type linkages and UCST-type pendants: Synthesis, characterization, and thermoresponsive properties
Water-soluble homopolypeptides bearing di(ethylene glycol) (DEG) linkages and various ionic liquid (IL) pendants with both lower and upper critical solution temperature (LCST and UCST) or a UCST were prepared and systematically investigated. Poly (γ-2-(2-chloroethoxy)ethyl l -glutamate) (PCEELG) with DEG linkage and reactive chloro groups can be readily prepared from ring-opening polymerization of γ-2-(2-chloroethoxy)ethyl l -glutamic acid based N-carboxyanhydride. Homopolypeptides were conjugated with various IL pendants and counteranions by nucleophilic substitutions and subsequent ion-exchange reactions. Homopolypeptide with DEG linkages and tributylphosphonium iodide (PEELG-TBP-I) showed interesting LCST < UCST (i.e., soluble-insoluble-soluble) dual thermoresponsive behavior in DI-H2O and NaI aqueous solutions. The LCST-type and UCST-type phase transition temperatures (T pts) were tunable by polymer concentration, molar mass, and NaI concentration. Homopolypeptide with DEG linkages and tributylphosphonium tetrafluoroborate showed a UCST both in DI-H2O and PBS buffer while homopolypeptide with DEG linkages and triphenylphosphonium iodide (or tetrafluoroborate) or with alkyl linkages and tributylphosphonium iodide (or tetrafluoroborate) showed a UCST in PBS buffer. The UCST-type T pt in PBS buffer was in a broad temperature range of 20–90 °C which was tunable by adjusting the polymer concentration, molar mass, IL moieties, and counteranions.

Publisher URL: www.sciencedirect.com/science

DOI: S0032386117310728

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.