Composition and salt concentration dependences of mechanical properties of poly(vinyl alcohol)/sodium polyalginate interpenetrated networks

Abstract

Mechanical properties of poly (vinyl alcohol)/sodium polyalginate (PVA/ ALG) interpenetrated networks (IPN) prepared by immersing PVA/ALG cast films in CaCl2 solutions are examined by simple elongation measurements. The ALG contents were 2.4, 9.1, and 16.7 wt% and the concentrations of CaCl2 solutions are varied from 0 - 2.2 M. The increment of Young's modulus ΔE = E - EPVA, where E and EPVA are Young's moduli for IPN and semi-IPN (CaCl2 = 0 M), was proportional to the CaCl2 concentration until cross-linking of ALG is saturated. At the higher CaCl2 concentrations, ΔE for the each sample became almost constant. The saturated values are proportional to the ALG content.