The characterization of polymer crosslinking density can be divided into qualitative and quantitative characterization. Low polymer crosslinking density can be quantificationally characterized by the method of simple swelling

while under the condition of smaller deformation

high polymer crosslinking density can be quantificationally characterized by dynamic thermomechanical analysis

polymer crosslinking density can also be quantificationally characterized by measuring glass transition temperature. The qualitative characterization of polymer crosslinking density can be divided into thermal characterization

mechanical property characterization

rheology

chemical characterization method

and functional characterization so on; thereinto

thermal characterization such as dynamic thermomechanical analysis can distinguish the intramolecular crosslinking from the intermolecular crosslinking. The characterization of rheology such as frequency sweep test can effectively control the gel point

which lets the viscous fluid into the gel.