Review of Refractive Index-Matching Techniques of Polymethyl Methacrylate in Flow Field Visualization Experiments

Table 2

Solubility parameters of common materials.

Materials	Solubility parameter ((J/cm^3)^1/2)
Rubber
Fluororubber	12.7
Silicone rubber	15.5
Natural rubber	16.9
Ethylene propylene diene monomer	17.0
Chloroprene rubber	19.2
Nitrile butadiene rubber	18.2-20.2
Macromolecular compound
Polytetrafluoroethylene	12.7
Polyethylene	15.8-17.1
Polystyrene	17.4-19.0
Polyvinyl chloride	19.2-22.1
PMMA	18.6-26.2
Polyvinyl alcohol	25.8-29.1
Plasticizer
Dibutyl phthalate	19.0
Diethyl phthalate	20.3
Dimethyl phthalate	21.9
Solvent
Turpentine	16.5
Cyclohexane	16.8
Carbon tetrachloride	17.6
Methylbenzene	18.2
Benzene	18.7
Tetrachloroethene	19.2
Tetralin	19.4
Carbon disulfide	20.4
Ethanol	26.0
Glycerol	33.6
Water	47.9