Polyurethane networks based on poly(ethylene oxide)

Abstract

A wide range of infinite urethane polymer networks were prepared from poly(ethy1-ene glycol) (PEG) and hexamethylene diisocyanate (HMDI) using l,l,l-tris-(hydroxymethy1)ethane (THME) as the cross-linking agent. The influence of temperature, cross-linking, and crystallinity on the swelling character of the hydrogel has been discussed. The toxicity of the network polymer by intravaginal implants in rats was studied. Implantation of the polymer did not result in alteration in behavior and feed intake or any pathological changes in the tissue. Vaginal fluids from the polymer-implanted rats or the polymer extract when inoculated on a listeria monocytogene culture plate were unable to inhibit the bacterial growth.

Structural Characteristics and Swelling Behavior of Poly(ethylene glycol) Diacrylate Hydrogels

“…In comparison we were convinced that PEGs are better candidates, since the network will respond uniformly to a given ambience. We anticipated no synthetic problems in forming the network because the terminal hydroxyl groups are susceptible to a variety of chemical reactions rendering easy derivatization. − …”

“…The polymerizations of PEGDAs have been reported but most of these have been purely kinetic studies. ,,− PEGDAs have been polymerized in both bulk and solution. − Many schools have observed an increase in the reaction rate with increase in the number of ethylene glycol units in the macromer. , A systematic approach to analyze the network character on the basis of the molecular weight of the PEG building block never seems to have been attempted. In this paper we first report the synthesis and characterization of PEGDA networks; next, we estimate the M c values based on the Flory−Rehner equation and compare it with expected values.…”

“…We anticipated no synthetic problems in forming the network because the terminal hydroxyl groups are susceptible to a variety of chemical reactions rendering easy derivatization. [4][5][6][7][8][9] Another attractive feature of PEGs is that they come in a wide range of molecular weights. This immediately opened up an excellent possibility to tackle one of the long-standing problems of networks, namely, the uncertainty of M c , the average molecular weight between cross-links in a polymer network.…”

Synthesis and characterization of multi-allyl-functionalized polylactic acid and polyhydroxybutyrate polyurethane, and their cross-linking by copolymerization with 2-hydroxylethyl methacrylate

“…Biodegradable polyurethanes (PUs) have been widely used in biomedical fields, 1 such as in blood-contact applications, contact lenses, surgical implants, and separation membranes, [2][3][4] because of their good physicochemical and mechanical properties while exhibiting acceptable biological performances. In recent years, these materials have also been extensively studied and used in new applications, such as thermo-responsive materials 5 and shape-memory materials 6 because of their contribution in the reduction of environmental issues inherent to nonbiodegradable materials.…”

UV-curable poly(ethylene glycol)-based polyurethane acrylate hydrogel

“…PU hydrogels are reported to have applications as contact lenses, surgical implants, and separation membranes. [3][4][5][6] UV curing saves energy and reduces or eliminates solvent emission in comparison with solvent-based systems because most formulations are 100% reactive oligomers and diluents. 3,[7][8][9][10][11] UV-curable urethane hydrogel is not only free of toxic solvent, but also minimizes possible side reactions upon application and has excellent optical properties.…”