High-strength hydrogels based onN-vinyl pyrrolidinone and 4-t-butyl-2-hydroxycyclohexylmethacrylate

Abstract

A nonionic, high‐water‐content, highstrength hydrogel based on N‐vinyl pyrrolidinone (NVP) and a novel hydrophilic‐bulky monomer, 4‐t‐butyl‐2‐ hydroxycyclohexylmethacrylate (TBCM), was developed. The TBCM was prepared in three relatively simple, high‐yield steps. The copolymerization of NVP with varying concentrations of TBCM resulted in transparent hydrogel films possessing a wide range in mechanical and physical properties. A copolymer composition of 91.7 parts NVP, 8.0 parts TBCM, and 0.3 parts ethylene glycol dimethacrylate (EGDMA) gave a transparent, flexible film possessing a water content of 86%, a modulus of 130 g/mm², and a tear strength of 3.4 g/mm. In contrast, a copolymer composition of 49.7 parts NVP, 50 parts TBCM, and 0.3 parts EGDMA gave a transparent, hard hydrogel film possessing a water content of 26% and a modulus of 86,000 g/mm². All of the high‐water co‐polymer compositions developed resulted in lysozyme uptake typical of nonionic high‐water‐content hydrogels and oxygen permeability levels greater than 50 (cm³ O₂(STP) · cm)/(s · cm2 · mm Hg) × l0⁻¹¹.