Poly(vinyl alcohol) (PVA) gels physically crosslinked by microcrystallites were prepared by a cast-drying method using PVA powders with different degrees of polymerization (n DP) between 300 and 2400 and hydrolysis (r DH) between 79.5 and 98.5 mol %. Polymer elution of gels in a limited amount of water was investigated by measuring the total carbon in the outer water by a total organic carbon analyzer. As a result, polymer elution was detected for all gels, the total amount of which depended on both n DP and r DH. In the cases of lower n DP and higher r DH, the gel became opaque and cracks were observed on the surface during a simple swelling process. On the other hand, polymers dissolved without cracks in the cases of higher n DP and lower r DH. These results are discussed on the basis of the network microstructure of the dried states before and after the polymer elution.
All Science Journal Classification (ASJC) codes
- Surfaces, Coatings and Films
- Polymers and Plastics
- Materials Chemistry