Development of potentially biocompatible hydrogels with cylindrical pores prepared from polyvinyl alcohol and low‐molecular weight polyacrylic acid

Abstract

In the present work, blend hydrogels from PVA and two different low PAA molecular weights, Mw 1800 g/mol and 5000 g/mol were prepared through the freezing thawing (F‐T) physical crosslinking method. The obtained materials were fully characterized by means of scanning electron microscopy (SEM) in order to analyze their morphology, gel fraction (GF) to determine the crosslinking degree and Fourier transformed infrared spectroscopy (FTIR) to analyze the PVA‐PAA interactions. Thermal characterizations [thermogravimetric analysis (TGA) and dynamic scanning calorimetry (DSC)] were conducted to study the relevant thermal characteristics. Sorption tests at different pH values (4 and 7) obtained from different aqueous systems were also inquired. The effects of PAA contents (between 1 and 5 wt%) and Mw of the used PAA on the hydrogel final properties were analyzed and related to the most probably PVA‐PAA interactions. POLYM. ENG. SCI., 59:1479–1488 2019. © 2019 Society of Plastics Engineers

Bentonite-composite polyvinyl alcohol/alginate hydrogel beads: Preparation, characterization and their use as arsenic removal devices

“…The hydrogels adsorption capacity could be tuned to have selective removal towards a desired pollutant by properly designing the materials during the preparation process. For example, functional groups with certain charges could be introduced by selecting the starting materials useful as hydrogel matrix (Khan and Lo, 2016;Mahdavinia et al, 2018;Ozay et al, 2009); and the general morphology and pores sizes could also be conveniently controlled not only by the employment of chemical substances but also by using specific preparation protocols (Dinu et al, 2013;Sanchez, L. M., Alvarez, 2019). Furthermore, the incorporation of fillers may lead to have composite hydrogels that in most cases offer unique properties.…”

A review on carboxylic acid cross‐linked polyvinyl alcohol: Properties and applications

“…Physical cross-linking comprises the techniques like freeze-thawing and gamma irradiation, whereas chemical cross-linking is carried out by chemical reagents that can react with the hydroxyl groups of PVA to bond the two different polymeric chains. [3,5,8] Physical methods of cross-linking of PVA are less popular due to high cost, difficulties in controlling the degree of cross-linking, and also the damage of polymer chains. [3] On the other hand, chemical modification of hydroxyl groups of PVA through cross-linking agents is simpler, cost-effective, and can be easily controlled.…”

High-Drug-Loading Amorphous Solid Dispersions via In Situ Thermal Cross-Linking: Unraveling the Mechanisms of Stabilization

“…During the PAA–PVA cross-linking reaction, a strong ester linkage (esterification) is formed between the hydroxyl group of PVA and the carboxyl group of PAA, while the thermal treatment of PAA above 150 °C also results in the formation of strong cross-linked intra- and intermolecular anhydrides (Figure ). , …”

“…Generally, as the q m value increases, the cross-linker density of the polymeric matrices decreases. , In the case of LH PVA, results showed a significantly higher extent of maximum initial swelling. This can be attributed to the lower initial degree of LH PVA crystallinity, leading to cross-linked networks having higher amounts of amorphous zones, which usually results in a larger swelling ability . Nevertheless, the systems prepared with LH PVA eventually reached a lower q m value, indicating that a higher cross-linking density and a larger ( ) value were achieved.…”