Solvent effect on volume shrinkage of Melamine-Formaldehyde gel in aging process
Solvent effect and volume shrinkage ratio in melamine-formaldehyde gel aging process were discussed.Volume shrinkage ratio was analyzed from two aspects,the aging-swelling balance and solvent effect.The results implied that the solution compositon(water and ethanol) would control the volume shrinkage ratio in aging process.Appropriate exchange steps for wet gel is that the mixture of the liquid in the gel and target solvent(ethand) is firstly used and the target solvent's content gradually rises until it is pure target solvent,then the MF aerogel which has little volume shrinkage is obtained.