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Synthesis and characterization of copolymers of diisocyanates and dialcohol

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2008
Keskin, Selda
This study was aimed to synthesize low molecular weight hydroxyl terminated polyurethane acrylate polymers that can be used in biomedical applications. Acrylate end capping via inter-esterification reaction was successfully achieved with the methacryloyl chloride addition to the hydroxyl ends of the polyurethane at low temperatures. Isocyanate terminated polyurethane acrylates were also synthesized for the sake of comparison. TDI, HDI and MDI were used as diisocyanates for urethane synthesis and they were end capped with MMA and HEMA. Nature of the monomers used had an effect on thermal, morphological, and rheological properties that were interpreted in terms of the level of hydrogen bonding and degree of phase separation. Synthesized polymers were characterized by NMR, FTIR-ATR, DSC, TGA, GPC, Mass Spectroscopy, SEM and rheometry. In the literature, polyurethane acrylate polymers have been synthesized from the isocyanate terminated polyurethanes in which the urethane chains were ended with isocyanate groups. However, the toxicity of the isocyanate groups limited their biomedical applications especially in prosthetic dentistry as a soft lining material. Therefore, it is inevitable to explore the cytotoxicity of polyurethane acrylate polymers. For this purpose, silver nanoparticles that have an average particle size of 40 nm, were incorporated to the synthesized polymers. This addition, which intends to improve the degree of cytotoxicity, was successful to a certain extent.