The current contribution presents the synthesis of poly[oligo(ethylene glycol) sorbate]s (PREG m Ss) by the t-Bu-P 4catalyzed group transfer polymerization (GTP) method, their postpolymerization modification at the backbone double bond, and thermoresponsive properties in aqueous solution. Four oligo(ethylene glycol) sorbate monomers (REG m Ss), including 2-(2methoxyethoxy)ethyl sorbate (MeEG 2 S), 2-(2-(2-methoxyethoxy)ethoxy)ethyl sorbate (MeEG 3 S), 2-(2-(2-ethoxyethoxy)ethoxy)ethyl sorbate (EtEG 3 S), and 2-(2-(2-(2-methoxyethoxy)ethoxy)ethoxy)ethyl sorbate (MeEG 4 S ), are newly designed to study the thermoresponsive properties of their related polymers. The t-Bu-P 4 -catalyzed GTP of REG m S only proceeds in a 1,4-regioselective addition manner to quantitatively produce the backbone trans-rich (ca. 80%) PREG m S. The complete hydrogenation and epoxidation of the backbone double bonds result in hydrogenated and epoxidized polymers (PREG m S-H 2 and PREG m S-epoxy, respectively), which have different main-chain structures and rigidity from their parent PREG m S. Given the 1,4-substituted structure of a sorbate monomer, the chemical structure determination of PREG m S-H 2 by 13 C NMR spectra demonstrates that the above polymers have an erythro-rich (ca. 60%) structure in diastereochemistry and a diisotactic/disyndiotactic ratio around 1:1 in stereoregularity. The thermoresponsive properties of PREG m S, PREG m S-H 2 , and PREG m S-epoxy in aqueous solutions are studied in detail from various aspects in terms of polymer mass concentration, molecular weight, length and end group of the oligo(ethylene glycol) side chain, and main-chain structure by turbidity, 1 H NMR spectroscopy, and dynamic light scattering (DLS) methods, which are discussed below.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.