The state of sorbed water in nylon-6 membranes grafted with acrylic acid (AA), acrylamide (AM) and p-styrenesulphonic acid (SS) was investigated by differential scanning calorimetry. There are three kinds of water in AA- and AM-grafted nylon-6 membranes: non-freezing water, intermediate water and free water. The SS-grafted nylon-6 membrane retains both non-freezing water and freezing water. In the latter, the intermediate water and the free water cannot be distinguished. Each kind of grafted membrane with high extent of grafting can retain a good deal of the non-freezing water and the intermediate water. This is due to an increase in the content of hydrophilic repeat units as graft copolymerization progresses. The SS repeat unit can retain a larger amount of water than can AA or AM. It was also found that the amount of non-freezing water per repeat unit increased in the order of AA-, AM- and SS-grafted nylon-6 membranes. The order reflects the nature of the homopolymers
Посилання на статтю:
The state of water in nylon-6 membranes grafted with hydrophilic monomers: 2. Water in acrylic acid, acrylamide and p-styrenesulphonic acid grafted nylon-6 membranes / Shoji Takigami*, Tomoaki Kimura and Yoshio Nakamura // Polymer. – 1993. – Vol 34. – P. 604-609.