Molecular Structure of Poly(vinyl alcohol)-Derived Carbon-Centered Radicals Studied by Rapid-Flow and Spin-Trapping ESR Measurements: A Short-Lived Intermediate Radical in the Initial Stage of the Graft Polymerization Reaction

2017 ◽  
Vol 90 (2) ◽  
pp. 244-253 ◽  
Author(s):  
Yuko Nishihara ◽  
Kazuma Matsui ◽  
Keiko Kuwabara ◽  
Naoya Murata ◽  
Tomoko Yamaguchi ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Vinyl Alcohol ◽  
Graft Polymerization ◽  
Spin Trapping ◽  
Polymerization Reaction ◽  
Poly Vinyl Alcohol ◽  
Intermediate Radical ◽  
Initial Stage ◽  
Rapid Flow

scholarly journals The Synthesis of Poly(Vinyl Alcohol) Grafted with Fluorinated Protic Ionic Liquids Containing Sulfo Functional Groups

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4158
Author(s):  
Patrycja Glińska ◽  
Andrzej Wolan ◽  
Wojciech Kujawski ◽  
Edyta Rynkowska ◽  
Joanna Kujawa
Keyword(s):  
Ionic Liquids ◽  
Vinyl Alcohol ◽  
Proton Exchange ◽  
Polymer Materials ◽  
Polymerization Reaction ◽  
Poly Vinyl Alcohol ◽  
Hydroxyl Groups ◽  
Protic Ionic Liquids ◽  
Synthesis Route ◽  
Sulfo Groups

There has been an ongoing need to develop polymer materials with increased performance as proton exchange membranes (PEMs) for middle- and high-temperature fuel cells. Poly(vinyl alcohol) (PVA) is a highly hydrophilic and chemically stable polymer bearing hydroxyl groups, which can be further altered. Protic ionic liquids (proticILs) have been found to be an effective modifying polymer agent used as a proton carrier providing PEMs’ desirable proton conductivity at high temperatures and under anhydrous conditions. In this study, the novel synthesis route of PVA grafted with fluorinated protic ionic liquids bearing sulfo groups (–SO3H) was elaborated. The polymer functionalization with fluorinated proticILs was achieved by the following approaches: (i) the PVA acylation and subsequent reaction with fluorinated sultones and (ii) free-radical polymerization reaction of vinyl acetate derivatives modified with 1-methylimidazole and sultones. These modifications resulted in the PVA being chemically modified with ionic liquids of protic character. The successfully grafted PVA has been characterized using 1H, 19F, and 13C-NMR and FTIR-ATR. The presented synthesis route is a novel approach to PVA functionalization with imidazole-based fluorinated ionic liquids with sulfo groups.

Effects of SiO2 and In Situ Crosslinking on the Swelling and Thermal Properties of Poly(vinyl Alcohol)/SiO2 Hybrid Films

2011 ◽  
Vol 266 ◽  
pp. 180-183 ◽  
Author(s):  
Jie Liu ◽  
Ke Yong Tang
Keyword(s):  
Vinyl Alcohol ◽  
Sio2 Film ◽  
Poly Vinyl Alcohol ◽  
Swelling Ratio ◽  
Hybrid Films ◽  
Initial Stage ◽  
In Situ Crosslinking ◽  
Hydrolysis Of ◽  
Thermal Stability Of

Poly(vinyl alcohol) (PVA)/SiO2 hybrid films were prepared through hydrolysis of tetraethoxysilane (TEOS) in the presence of PVA solution, followed by the in-situ crosslinking with formaldehyde (HCHO) in acidic circumstance. The swelling and thermal gravimetric (TG) analysis was employed to evaluate the influence of SiO2 and crosslinking on the properties of the hybrid films. The results indicate that SiO2 affects effectively the swelling property and thermal stability of the hybrid films because of both the filling and crosslinking effects of SiO2. With increasing the crosslinking time, the swelling ratio at equilibrium of the hybrid films decreases. The swelling ratio at equilibrium of the hybrid films is sensitive to the SiO2 content, which is similar to the swelling ratio at equilibrium (65~75%) for PVA and PVA/SiO2 hybrid films with enough crosslinking time (12h). Compared to the film without in-situ crosslinking, the crosslinked PVA/SiO2 film showed a lower swelling ratio at equilibrium and an increased diffusion coefficient at the initial stage of swelling.

Cationic Graft Polymerization of 2-Oxazolines on Poly(vinyl alcohol) Derivatives

1989 ◽  
Vol 28 (7-8) ◽  
pp. 877-890 ◽  
Author(s):  
Isao Ikeda ◽  
Yoshiaki Kurushima ◽  
Kimihiro Suzuki
Keyword(s):  
Vinyl Alcohol ◽  
Graft Polymerization ◽  
Poly Vinyl Alcohol

scholarly journals Outstanding flame retardancy for poly(vinyl alcohol) achieved using a resveratrol/tannic acid complex

RSC Advances ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 285-296
Author(s):  
Yuan Lin ◽  
Jialian Chen ◽  
Hongzhou Li
Keyword(s):  
Molecular Structure ◽  
Tannic Acid ◽  
Flame Retardancy ◽  
Vinyl Alcohol ◽  
Poly Vinyl Alcohol ◽  
Acid Complex ◽  
Complete Combustion ◽  
Residual Amount

The rigid molecular structure of biobased resveratrol/tannic acid (RETA) complex increases the residual amount of RETA-poly(vinyl alcohol) after complete combustion.

scholarly journals Fast and Highly Efficient Adsorption Removal of Toxic Pb(II) by a Reusable Porous Semi-IPN Hydrogel Based on Alginate and Poly(Vinyl Alcohol)

2021 ◽  
Vol 9 ◽  
Author(s):  
Wenbo Wang ◽  
Xiangyu Liu ◽  
Xue Wang ◽  
Li Zong ◽  
Yuru Kang ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Adsorption Kinetics ◽  
Vinyl Alcohol ◽  
Gel Strength ◽  
Second Order ◽  
Polymerization Reaction ◽  
Sodium Acrylate ◽  
Poly Vinyl Alcohol ◽  
Order Kinetic ◽  
Pseudo Second Order

A porous semi-interpenetrating network (semi-IPN) hydrogel adsorbent with excellent adsorption properties and removal efficiency towards Pb(II) was prepared by a facile grafting polymerization reaction in aqueous medium using natural biopolymer sodium alginate (SA) as the main chains, sodium acrylate (NaA) as the monomers, and poly(vinyl alcohol) (PVA) as the semi-IPN component. FTIR, TGA and SEM analyses confirm that NaA monomers were grafted onto the macromolecular chains of SA, and PVA chains were interpenetrated and entangled with the crosslinked network. The incorporation of PVA facilitates to form pores on the surface of hydrogel adsorbent. The semi-IPN hydrogel containing 2 wt% of PVA exhibits high adsorption capacity and fast adsorption rate for Pb(II). The best adsorption capacity reaches 784.97 mg/g, and the optimal removal rate reaches 98.39% (adsorbent dosage, 2 g/L). In addition, the incorporation of PVA improved the gel strength of hydrogel, and the storage modulus of hydrogel increased by 19.4% after incorporating 2 wt% of PVA. The increase of gel strength facilitates to improve the reusability of hydrogel. After 5 times of regeneration, the adsorption capacity of SA-g-PNaA decreased by 23.2%, while the adsorption capacity of semi-IPN hydrogel only decreased by 10.8%. The adsorption kinetics of the hydrogel in the initial stage (the moment when the adsorbent contacts solution) and the second stage are fitted by segmentation. It is intriguing that the adsorption kinetics fits well with both pseudo-second-order kinetic model and pseudo-first-order model before 60 s, while only fits well with pseudo-second-order adsorption model in the whole adsorption process. The chemical complexing adsorption mainly contribute to the efficient capturing of Pb(II).

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