According to the structural design of porous resin

CMC-g-PAM/PAAS porous resin was prepared by the twice foaming method.The morphology and structure properties of the resin were characterized by thermogravimetry (TG)

scanning electron microscopy (SEM)

X-ray diffractometer (XRD)

Fourier transform infrared spectroscopy (FTIR) and nitrogen adsorption.Humidity-controlling capability and maximum moisture content of the porous resin were tested under high humidity and low humidity conditions.Humidity-controlling capability was investigated at changing absolute humidity and temperature.The results showed that when aluminum chloride was 2.5%（mass） of the acrylamide monomer

the porous resin showed a humidity-controlling range of 57.5%—62.5%

its maximum moisture content was 122% of its own mass.The porous resin was able to maintain relative humidity in the range of 57.5%—62.5% also in the case of changing absolute humidity. The porous resin reached equilibrium humidity in less than 1 h at 40℃ and in less than 3 h at 10℃.