A New Blending Method for the Preparation of Macroporous Open‐cell Polyvinyl Formaldehyde Foams with High Water‐Absorption Capacity. Issue 27 (18th July 2022)

• Record Type: Journal Article
• Authors: Li, Yuanpeng; Pu, Taohong; Wu, Xun
• Is Part Of: ChemistrySelect. Volume 7:Issue 27(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-07-18
• Subjects: polyvinyl alcohol -- PVF foam -- Structure elucidation -- Chemoselectivity; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/slct.202201042
• Languages: English
• ISSNs: 2365-6549

Abstract

Abstract: A new blending method for the preparation of a series of macroporous open‐cell polyvinyl formaldehyde (PVF) foams is reported here. Mechanism of foam‐formation was detailedly analyzed and it was found that the addition of polyvinyl alcohol (PVA) with a low degree of polymerization was important and crucial for the formation of PVF foams. Further, the addition of PVA with a low degree of polymerization is beneficial for the improvement of water solubility. The structures and properties of PVF foams were investigated by Fourier transform infrared (FTIR), scanning electron microscope (SEM), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The macroporous open‐cell PVF foams had a pore size ranging from 120.88 to 16.16 μm with an increased degree of acetalization and the water absorption capacity increased with the addition of PVA with a low degree of polymerization. PVF foams generally have higher thermal stability because of their cross‐linked network structure. The highest water absorption capacity of the PVF foam obtained presently can reach up to 960 wt%, which is much higher than most PVF foams reported so far. Abstract : When two types of PVAs are blended, formaldehyde will preferentially and quickly react with the PVA with a low degree of polymerization to form a skeleton structure. Due to the formation of the skeleton structure, the PVF foam will gain support and prevent a collapse during the drying process, thereby facilitating the reaction between formaldehyde and the PVA with a high degree of polymerization to form the internal pore structure.