2.6. Water Sorption of Adhesive Polymer

The experimental protocol for the water sorption analyses has been reported [28]. In brief, five disc-shaped specimens were prepared for each polymer formulation. After 1-hour post-processing at 23 ± 2 °C, the samples were immersed in distilled water to prewash for 7 days at 23 ± 2 °C. Next, the specimens were dried in a convection oven at 37 °C for 2 days, and then stored in a vacuum oven in the presence of freshly dried silica gel at 37 °C. The samples were removed every 24 h and weighed using an electronic balance (Mettler Toledo, XS205 Dual range, Columbus, OH, USA). The procedure continued until a constant mass (m₁) was measured. Thus, the process for water sorption involved prewash (7 days), drying and weighing every 24 h until a constant mass was achieved, and finally, the dried specimens were soaked in distilled water. The samples were removed from the water at fixed intervals (3 h, 6 h, 12 h, 24 h, 48 h, and 72 h), blotted to remove excess water, weighed (m₂) and returned to the water until a constant weight was obtained. The values (%) for water sorption (W_sp) were calculated by the following equation: