Ten different polymers were selected as possible matrix for zeolite containing desiccant composites in order to prepare functional packaging material. Water uptake was determined at 100 % RH and the results were analyzed to identify factors influencing the capacity and rate of water adsorption. The results showed that the desiccant can adsorb considerable water in its free pores. The adsorption capacity of the composites depends linearly on the amount of desiccant present, but it is independent of the type of polymer used.The diffusion of water into the composites is fast initially, but slows down with time and also with increasing desiccant content. This latter effect can be explained with the increase of the diffusion path as zeolite content increases. The initial rate of diffusion depends solely on the specific free volume of the matrix and this factor influences strongly also the overall rate of water adsorption. However, this latter characteristic depends also on other factors like the dispersion of the desiccant in the matrix. Matrix type and zeolite content must be selected according to the task to be fulfilled; fast adsorption can be achieved only with polymers having large free volume.

Ten different polymers were selected as possible matrices for zeolite containing desiccant composites in order to prepare functional packaging material. A 5A type zeolite was used as desiccant. Composites containing the zeolite up to 50 vol% were prepared.