Radical/Addition polymerization silicone hydrogels with simultaneous interpenetrating hydrophilic/hydrophobic networks

Abstract

Transparent silicone hydrogels with interpenetrating hydrophilic/hydrophobic networks were simultaneously synthesized on the basis of the radical polymerization of the methacrylic monomer of 3‐methacryloxypropyl tris(trimethylsiloxy) silane (TRIS)/N,N‐dimethylacrylamide (DMA) and the addition polymerization of hydroxyl‐grafted polysiloxane (HPSO)/isophorone diisocyanate. The curing temperature was set at 80°C by a differential scanning calorimetry study. The polymerization process was studied by in situ Fourier transform infrared spectroscopy. The results indicate that the curing time was about 4.5 min, and the addition polymerization had a faster rate than radical polymerization. Then, the radical polymerization rate increased rapidly, and this led to instant curing. The interpenetrating polymer network (IPN) silicone hydrogels were characterized by swelling kinetics and dynamic mechanical thermal analysis. The results show that all of the hydrogels reached swelling equilibrium at about 4 h in water, and the IPN silicone hydrogels with a hydrophobic network of HPSO indicated a slower water transport than that of the copolymerization hydrogel of DMA and TRIS. The hydrophobic network was finely dispersed in the hydrophilic network, and the increasing hydrophobic network of HPSO decreased the glass‐transition temperature of the IPN silicone hydrogels. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41399.

Inorganic–Organic Interpenetrating Network Hydrogels as Tissue‐Integrating Luminescent Implants: Physicochemical Characterization and Preclinical Evaluation

“…This is consistent with previous TRIS‐containing IPN hydrogel reports for contact lenses. [ 15,18 ] However, the loss in transparency seen here was considerable and therefore was investigated further for an underlying cause. We hypothesized that, because TRIS is hydrophobic, at the higher concentrations of TRIS (70–80% in the first network) portions of pTRIS would not be adequately reinforced by the pDMA second network.…”

“…Similar trends have been observed in previous studies using DMA as a wetting agent for contact lenses. [11,17,18,20,62]…”

“…In the case of contact lenses, these attributes include excellent optical clarity, high oxygen permeability, low modulus with flexural toughness, wettability/hydration, and resistance to fouling by proteins and other particulate matter. [2,3,[7][8][9][10][11][12][13][14][15][16][17][18][19] Additional features have also been added to contact lenses, such as incorporation of small molecules that are released for local therapeutic effect. For example, the Sheardown group has functionalized pHEMA hydrogels with various comonomer combinations including [3-methacryloyloxypropyl] tris trimethylsilyl siloxy silane (TRIS) and dimethylacrylamide (DMA) for the release of various drugs to the anterior eye.…”

A Simple Synthesis of Higher Refractive Index Polymeric Nanocomposite Containing the Pendant ZnS Nanocrystals Capping Different Amount of Mercaptoethanol

“…In the hydrogels with high water content, polymer backbone has usually little influence on its RI value. Therefore, its RI value can be calculated according to their water content [27]. The hydrogel by copolymerization between polymerizable-group-capped ZnS has a higher RI value compared to reported hydrogels with a similar water content, e.g., the RI value of hydrogel with 30 wt% ZnS (ESR: about 70%, RI: about 1.39) is higher than that of Nefilcon A hydrogel (ESR: 69%, RI: 1.38); the RI value of hydrogel with 50 wt% ZnS NPs (ESR: about 47%, RI: 1.46) is higher than that of polymacon hydrogel (water content: 38.6%, RI: 1.43).…”

Fabrication of contact lens containing high-performance wire grid polarizer

“…Many hydrophilic monomers have been copolymerized with PHEMA to fabricate contact lenses. Recently, a silicone‐containing hydrogel moiety has been shown to increase oxygen permeability …”