Polymer drying. III. Comparison of molecular desorption from poly(styrene-co-divinylbenzene) in the gel-state and in the glass-state

The results observed in 44 time-studies that monitored evaporation from liquid-saturated poly(Sty-co-DVB) particles enmeshed in poly(tetrafluoroethylene) microfibers under conditions that precluded decrease in area of the microporous composite film sample verified that after the enmeshed particles undergo transition from the gel-state to the glass-state, the number of residual adsorbed molecules per phenyl group of polymer is given by a linear combination of n < 7 exponential decay functions, the first order rate constants of which are related to one another by the equation: log k_i = log k₀ ? mi, where m is characteristic of the polymer, and k₀ is characteristic of the sorbed liquid such that k₁ is about 10⁵ times faster than k₆. The results also show that k₁ of the set of nk_i for desorption from poly(Sty-co-DVB) in the glass-state is equal to k_gel, the first-order rate constant for desorption of the test-liquid from that polymer in the gel-state. These results are interpreted to mean that i, the identification number of the ith population, reflects the number of phenyl groups in the “host” polymer with which the “guest” volatile molecule is associated simultaneously as discussed in the text.