NMR study of poly(vinylpyrrolidone)/poly(ethylene oxide) blends

Abstract

Development of polymeric blends has become very important for polymer industries because they have been shown to be successful and versatile alternatives to obtain new polymers. In this work binary blends formed by poly(vinylpyrrolidone) (PVP) and poly(ethylene oxide) (PEO) were studied by solution and solid-state NMR to determine their physical interaction, homogeneity, and compatibility for use as membranes to separate water/alcohol. The NMR results allowed us to acquire information on the microstructure and molecular dynamic behavior of polymer blends. From the NMR solution it was possible to evaluate the microstructure: PVP presented a preferential syndiotactic distribution sequence and PEO presented two regions, one crystalline and the other amorphous. Considering the solid-state NMR results it was possible to evaluate the molecular dynamics and all binary blends, showing that PEO behaves as a plasticizer; some intermolecular interaction was also observed. An important point was to evaluate the microstructure of the carbonyl PVP using cross polarization/magicangle spinning (CP/MAS) and CP/MAS/dipolar decoupling that was not observed before.

Synthesis of Amphiphilic Copolymers of N-Vinyl-2-pyrrolidone and Allyl Glycidyl Ether for Co-Delivery of Doxorubicin and Paclitaxel

“…The assignment of signals in the 13 C NMR spectrum of the synthesized amphiphilic copolymer is shown in Figure 1 (the signal of carbon atom I of the pyrrolidone ring has a chemical shift of 172.81 ppm) and is consistent with the presence of N-vinyl-2-pyrrolidone and allyl glycidyl ether residues in the chain, as well as the terminal n-octadecyl group. When assigning the signals, we used the literature data on the analysis of 13 C NMR spectra of polymers and copolymers of N-vinyl-2-pyrrolidone [55,56].…”

“…In the IR spectra of the synthesized amphiphilic copolymer of N-vinyl-2-pyrrolidone and allyl glycyl ether (Figure 2A), signals characteristic of poly(N-vinyl-2-pyrrolidone) are clearly manifested, and there are also signals at 1049.5 and 1089.7 cm −1 caused by asym- When assigning the signals, we used the literature data on the analysis of 13 C NMR spectra of polymers and copolymers of N-vinyl-2-pyrrolidone [55,56].…”

“…The presence of these signals is associated with the presence of allyl glycidyl ether residues in the polymer chain [57]. When assigning the signals, we used the literature data on the analysis of 13 C NMR spectra of polymers and copolymers of N-vinyl-2-pyrrolidone [55,56].…”

A high‐resolution solid‐state NMR investigation of molecular mobility of poly(methyl methacrylate)/poly(vinyl pyrrolidone)/poly(ethylene oxide) ternary blends

“…The proton spin-lattice relaxation time in the rotating frame is highly important and it is used to study the dynamic of samples, because it is sensitive to molecular motions in a frequency of tens of kilohertz. [1][2][3][4][5][6][7][8][9][10] In summary, the focus of this work is to understand the molecular mobility behavior of the PMMA/PVP/PEO ternary blends, to evaluate the blend components miscibility and interaction.…”

“…Solid-state NMR also offers a great variety of relaxation times and they are informative on molecular mobility, in distinct time scales. [1][2][3][4][5][6][7][8][9][10] The spin-lattice relaxation process is generally dominant in solid state giving direct information on molecular motion. The proton spin-lattice relaxation time in the rotating frame is highly important and it is used to study the dynamic of samples, because it is sensitive to molecular motions in a frequency of tens of kilohertz.…”