Effect of crosslinking concentration on properties of 3-(trimethoxysilyl) propyl methacrylate/N-vinyl pyrrolidone gels

Abstract

BackgroundThe incorporation of two different monomers, having different properties, in the same polymer molecule leads to the formation of new materials with great scientific and commercial importance. The basic requirements for polymeric materials in some areas of biomedical applications are that they are hydrophilic, having good mechanical and thermal properties, soft, and oxygen-permeable.ResultsA series of 3-(trimethoxysilyl) propyl methacrylate/N-vinyl pyrrolidone (TMSPM/NVP) xerogels containing different concentration of ethylene glycol dimethacrylate (EGDMA) as crosslinking agent were prepared by bulk polymerization to high conversion using BPO as initiator. The copolymers were characterized by FTIR. The corresponding hydrogels were obtained by swelling the xerogels in deionized water to equilibrium. Addition of EGDMA increases the transparency of xerogels and hydrogels. The minimum amount of EGDMA required to produce a transparent xerogel is 1%. All the Swelling parameters, including water content (EWC), volume fraction of polymer (ϕ2) and weight loss during swelling decrease with increasing EGDMA. Young’s and shear modulus (E and G) increase as EGDMA increases. The hydrogels were characterized in terms of modulus cross-linking density (ve and vt) and polymer-solvent interaction parameters (χ). Thermal properties include TGA and glass transition temperature (Tg) enhance by adding EGDMA whereas the oxygen permeability (P) of hydrogels decreases as water content decrease.ConclusionsThis study prepared and studied the properties for new copolymer (TMSPM-co-NVP) contains different amounts of (EGDMA). These copolymers possess new properties with potential use in different biomedical applications. The properties of the prepared hydrogels are fit with the standard properties of materials which should be used for contact lenses.

Physicochemical Characteristics of Chitosan-Based Hydrogels Modified with Equisetum arvense L. (Horsetail) Extract in View of Their Usefulness as Innovative Dressing Materials

“…As a result, such crosslinked material showed fewer free spaces in its polymer network available for absorbed liquid, and hence this material had a lower swelling ratio. Similar conclusions concerning the dependance between the swelling ratio and the crosslinking density were drawn in studies presented in [33][34][35][36][37]. Moreover, it was proved that there was a slight difference between swelling ability of unmodified hydrogels and hydrogels containing horsetail extract, i.e., modified materials swelled slightly more.…”

Characterization and analysis of extended‐wear silicone hydrogel contact lenses utilizing novel silicone macromers

“…Thus, for all lens systems studied and presented in Figure3, which had ratios of 1.4, 2.6, and 7.5, modulus values less than 1 MPa can be achieved. A common trend therefore in Figure4is a decrease in the concentration of crosslinker resulted in an decrease in elastic modulus, which is seen in the literature for other hydrogel systems 31,32. Another common trend is that compositions with longer crosslinking monomers at a fixed crosslinker concentration resulted in polymers with decreased modulus.…”

Double-Crosslinked Polyurethane Acrylate for Highly Conductive and Stable Polymer Electrolyte

“…These results confirm that additional PU crosslinking enhanced the stiffness of the PUA membrane. Because the Young's modulus is a measure of the degree of crosslinking [20,21], our results are evidence that PUA samples with higher value (i.e., TMP/PEG ratio) have a higher degree of crosslinking. The tensile strength, Young's modulus, and fracture strain of the PUA membranes range from 90 to 120 kPa, 0.7 to 1.4 MPa, and 10% to 20%, respectively.…”