Structure–property correlations for composite hydrogels based on poly(methacrylic acid) and high concentrations of LTA zeolite

Abstract

High concentrations of LTA zeolite (27-52mass%) were embedded in poly(methacrylic acid) (PMAA) matrix to obtain composite hydrogels with porosity and active sites originating from both components. Substandard mechanics of PMAA and aggregation of zeolite particles, were thereby overcome. The composites had remarkably higher density than PMAA xerogel (1700 to1400 kg m−3), higher crosslinking density (54.8 to1.29 mol m−3) and lower swelling degree (41 to 420 kg kg−1). Zeolite particles were uniformly dispersed in PMAA matrix and there was no agglomeration or leaching of zeolite despite very high concentrations. XRD patterns revealed that the inclusion of zeolite particles affected the short-range order in the PMAA matrix. Being an active filler LTA zeolite notably improved thermal stability and mechanics of PMAA hydrogel, multiplying the storage modulus 5.2 times in dry and 21.8 times in swollen state. Structure–property correlations were provided making the base for further development of tailor-made zeolite-PMAA composite hydrogels.