A new process for preparation of porous polyacrylamide resins and their humidity control properties

• We report a new process to prepare humidity control materials.
• The process is easy to perform and does not produce any harmful resultant.
• This material can serve as intelligent humidity control material.
• Good properties depend on the surface area and the distribution of pores.
• Possible reasons for humidity control properties are discussed.

A new process for preparation of porous acrylamide resins has been proposed. The process is that Al(OH)3 obtained from the reaction of aluminum chloride and sodium bicarbonate in solution is cross-linked with acrylamide copolymer in copolymerization and then dehydrated and converted into γ-Al2O3 at 142 °C. Therefore, lots of pores are generated in the acrylamide copolymer by means of water vapor released from the dehydration of Al(OH)3. The mesoporous structure of the copolymer is demonstrated by the scanning electronic microscope (SEM) and isothermal adsorption of nitrogen. Results show that one of the prepared porous acrylamide copolymers with a specific surface area (ABET) of 113.03 m2 g−1 and an average pore size of 15.82 nm possesses excellent humidity control properties. It can maintain the relative humidity (RH) between 50% and 60% in 3.5 h at 25 °C and can present a maximum moisture content of 134% of its own weight. It also shows good buffering effect to RH fluctuation at changed ambient temperatures. This work provides useful information for preparing humidity control materials for museum, gallery display cases and artifacts transportation in particular.