Novel Densely Alkylated Hydroxyl‐Functional Polyvinylpyrrolidone Showing Phase‐Selective Solubility

Abstract

Summary: Polyvinylpyrrolidone (PVP) is a commonly used polymer with many different applications in the pharmaceutical, cosmetic and food industries. However, the lack of reactive groups and the difficulty in copolymerizing the monomer, N‐vinylpyrrolidin‐2‐one (NVP) with most other monomers, limits the possibility of modifying the physical and chemical properties of the polymer. Monomers that are derivatives of NVP itself are expected to show small differences in radical reactivity as compared to the parent monomer and provide a way of adjusting the polymer properties without extensive compositional drift during copolymerization. Here we present the synthesis of two new functionalized NVP‐based monomers and their copolymerization with alkylated NVP‐monomers for the preparation of two functionalized PVPs with phase‐selective solubility in heptane. Both copolymers showed 99.99% selective solubility in heptane over DMF (thermomorphic system) and 99.99% in heptane over 90% EtOH‐H2O (latent biphasic system). These results suggest that the polymers could be used as soluble supports to facilitate recovery and recycling of catalysts or reagents from liquid/liquid systems after homogeneous reactions.Phase‐selectively soluble polyvinylpyrrolidone copolymer.magnified imagePhase‐selectively soluble polyvinylpyrrolidone copolymer.

Novel Polyvinylpyrrolidones To Improve Delivery of Poorly Water-Soluble Drugs: From Design to Synthesis and Evaluation

“…The resulting cross-linker, containing two NVP residues, was found to be readily compatible with NVP under photoinitiated free radical polymerization conditions, producing homogeneously cross-linked materials. This approach to synthesizing cross-linked NVP has recently been exploited by Engström et al to produce supports for solid phase synthesis and water swellable drug delivery systems. − …”

“…This approach to synthesizing cross-linked NVP has recently been exploited by Engstrom et al to produce supports for solid phase synthesis and water swellable drug delivery systems. 20−22 Our targeted diNVP cross-linkers were accessed through the addition of the known hydroxy functionalized NPV derivative 21,22 to either of the commercially available ditosylates (Figure 3). It should be noted that attempts to form oligoether cross-linkers by direct addition of NVP to the ditosylates under basic conditions failed as a consequence of over alkylation of the NVP ring, which led to a complex mixture of cyclic and oligomeric species.…”

A Combinatorial Approach to Studying the Effects of N-Alkyl Groups on Poly(N-alkyl and N,N-dialkylacrylamide) Solubility

“…For example, soluble polymers like poly(ethylene glycol) whose end groups are modified to support catalysts, poly( N -isopropylacrylamide) with 1−5 mol % of the pendant amides modified to serve as catalyst ligands, , or poly(acrylic acid)-supported catalysts can be ≥99.9% selectively soluble to the polar phase of a heptane/DMF or heptane/ethanol/water system. Nonpolar more hydrophobic polymers like terminally poly(isobutylene), , poly( tert -butylstyrene), poly(octadecylacrylate)s, poly( N -vinyloxazoline)s, poly( N -octadecylacrylamide), or polydimethylsiloxanes can be equally phase-selectively soluble in the nonpolar phase of these same solvent mixtures so long as the mole percent loading of pendant groups or of terminal groups used as ligands or catalysts is <5 mol %. Similar effects are seen with fluorous polymer-bound catalysts in fluorous/organic thermomorphic systems. , However, while these polymers exhibit useful phase-selective solubility, greater versatility and higher loadings of reagents or catalysts might be possible using soluble polymer supports if copolymers can be designed where one of the copolymer substituents can define the phase-selective solubility of the polymer-supported species.…”