Drying and shrinkage of polymer gels

S. S. Waje, M. W. Meshram, V. Chaudhary, R. Pandey, P. A. Mahanawar, B. N. Thorat
2005 Brazilian Journal of Chemical Engineering  
The polymer hydrogel was synthesized by photo-polymerization process (UV light, 60 O C) in presence of Photo-initiator (Irgacure R ) and Cross-linker (NN'-methylene bisacrylamide; MBAM). In the present work, the drying of polymer hydrogel was carried out to study the effect of temperature, gel-sheet thickness, monomer ratio of acryl acid to acrylamide (AA/AM), concentration of MBAM and quantity of monomers. A correlation has been developed for modified sheet thickness as a function of
more » ... n coefficient and degree of drying. Effective diffusivity was estimated from Fickian-diffusive model considering modified sheet thickness and was found to be in the range of 1.1 × 10 -10 -5.93 × 10 -10 m 2 /s. The activation energy obtained using Arrhenius type equation was found to be in the range of 2979-10737 kJ/kmol H 2 O. The drying behavior shows an initial shoot-up in drying rate followed by constant rate and two falling rate periods.
doi:10.1590/s0104-66322005000200007 fatcat:gwobn32l4fcj3pdv6opvngytiq