CONSIDERATION ACCORDING TO THE MECHANICAL MODEL, FOR MECHANICAL BEHAVIORS OF POLYMER FILM DURING THE SORPTION PROCESS

The multi-phases parallel model for blend polymer solids was applied to express the mechanical properties of polymer film in the course of sorption of small molecules; the following relations were obtained. 1) The following fundamental equations developed. With X: film thickness, x: distance from the film surface in the direction of the thickness, a: distance where the small molecules are diffused, C(x, t): concentration distribution at time t (mass/volume), q (t ): amount of absorbed small molecules at t (mass/volume), E: elastic modulus of polymer during the sorption process, EA(x, t): elastic modulus distribution, Ep: elastic modulus of pure polymer, F: function between EA and C at time t. 2) When the relation between EA and C is linear, equation (9) is obtained by using the equations (3), (4) and (5). 3) Assuming the three typical distributions of concentration and elastic modulus, the relations between E and q(t)/q(∞) were calculated for various relations between EA and C (see fig. 3 and fig. 4). 4) The elastic modulus on the surface of film, EA(O, t) is given by following euqation. With ka: reaction velocity constant. 5) Characteristic temperature dispersions of complex elastic modulus for polymer film during the sorption process were obtained by using the blend polymer theory (see fig. 6)