Journal of Applied Polymer Science, Vol.64, No.11, 2141-2148, 1997
Elastic and Swelling Behavior of 2-Hydroxyethyl Methacrylate, Diethylene Glycol Methacrylate, and Methacrylic-Acid Copolymers
The elastic and swelling behavior of copolymers of 2-hydroxyethyl methacrylate, diethylene glycol methacrylate, and methacrylic acid crosslinked with ethylene glycol dimethacrylate has been studied. In the range of copolymer composition studied, Young’s modulus of the swollen networks increases with the content of methacrylic acid, and its dependence on the content of diethylene glycol methacrylate passes through a maximum. The concentrations of the elastic network chains determined from Young’s moduli of swollen networks are much higher than those : calculated from stoichiometry. This effect is attributed to the presence of additional physical crosslinks due to water-induced ordering of the hydrophobic backbone chains. Both the elastic and swelling behavior of the polymers mentioned above are decisive for their application in the preparation of soft contact lenses.