Swelling Resistance and Mechanical Performance of Physical Crosslink‐Based Poly(Vinyl Alcohol) Hydrogel Film with Various Molecular Weight

Abstract

The present work aimed to develop polyvinyl alcohol (PVA) hydrogel films with physically crosslinking through controllable entanglement density of the polymer chains. The viscoelasticity of PVA aqueous solutions was investigated over a broad range in molecular weight. The chain length between the crosslinks in the hydrogel (falseMe¯) and entanglement density was determined by the plateau modulus (G'). The value of (falseMe¯) increased with the PVA molecular weight, which can be attributed to the enhanced entanglement associated with the hydrogen bonds between inter‐ and interchains. The melting and crystallization of the transparent PVA hydrogel films showed that the crystallinity was below 30%, which indicated that microcrystallites formed. Therefore, the entanglement effect and microcrystallization enhanced the stable crosslinked hydrogel network, which further improved by an increase in the molecular weight. Altogether, the PVA with the molecular weight higher than 88,000 g/mol can be envisioned as a promising material for preparing the hydrogel film possessing excellent performance. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019, 57, 1673–1683

PVA/Poly(hexamethylene guanidine)/Gallic Acid Composite Hydrogel Films and Their Antibacterial Performance

“…In the case of the PVA and PVA-COOH films, the PVA film is more stable than the PVA-COOH film, and the reason may be related to the decreased degree of crystallinity of PVA-COOH film. 43 For PCP-1/2 films, the weight loss is less than the PVA-COOH film at the initial stage; however, its thermal stability is still lower than that of pure PVA. The presence of GA is conducive to improving the thermal stability of the films at the first degradation stage, especially for the PCP-2/GA(10 wt %) film (Table 1).…”

“…The temperatures at 5% and 10% weight loss ( T 5% , T 10% ) are selected as reference index (Table ). In the case of the PVA and PVA-COOH films, the PVA film is more stable than the PVA-COOH film, and the reason may be related to the decreased degree of crystallinity of PVA-COOH film . For PCP-1/2 films, the weight loss is less than the PVA-COOH film at the initial stage; however, its thermal stability is still lower than that of pure PVA.…”

Bioinspired Crosslinked Nanocomposites of Polyvinyl Alcohol‐Reinforced Cellulose Nanocrystals Extracted from Rice Straw with Ethanedioic Acid

“…PVOH is a hydrophilic material that tends to easily attract water molecules owing to its free hydroxyl groups. The difference in the swelling behavior is attributed to its crystallinity, where the non-crosslinked nanocomposite films with higher CrI values augmented the difficulty of the water to penetrate the PVOH network [83]. The formation of dense, three-dimensional network structures as a result of crosslinking additionally reduced the intermolecular spaces.…”

Improved antifouling and drug delivery properties of polyvinyl alcohol hydrogel by grafting with N‐isopropylacrylamide via organic dye photocatalyzed PET‐RAFT polymerization

“…Surface morphology of hydrogel was observed by scanning electron microscope (SEM, S3400N, HITACHI, JAP) and atomic force microscopy (AFM, MultiMode 8, BRUKER). Hydrophilicity of hydrogel was evaluated via swelling equilibrium experiment (gravimetric method) 51 and water contact angle was examined by a contact angle goniometer (JC2000C1, Shanghai Zhongchen Co., LTD, CN) at 25 and 37 C. Swell ratio (SR) and moisture content were calculated by Equations ( 1) and (2), respectively.…”