aqueous polyurethane dispersions (puds) have recently emerged as important alternatives to their solvent-based counterparts for various applications due to increasing health and environmental awareness (green chemistry). anionic polyester-polyurethane dispersions were synthesized by three steps. in the first step, macromonomer diisocyanate having carboxylic acid was prepared by isophorone diiso...

Environmentally friendly, polyacrylic-based polyurethane dispersion (PUD) was synthesised using various molar ratios of polycaprolactone, dimethylolpropionic acid and tetramethyl xylene diisocyanate. Synthesis was carried out in flowing nitrogen atmosphere. The PUD’s preparations are free of NMP (n-methyl pyrrolidone), a toxic processing solvent generally used during the preparation of PUD’s. T...

In the reaction of 4,4'-methylenebis(phenyl isocyanate), polycaprolactone diol, and N-methyldiethanolamine, they were synthesized aqueous dispersions of polyurethane cationomers, from which films were prepared after adding 0-2 wt% graphene. In order to obtain nanocomposites, graphene was previously noncovalent functionalized in tetrahydrofurane in the field of ultrasound. The chemical structure...

BACKGROUND Emulsifiers have a significant role in the emulsion polymerization by reducing the interfacial tension thus increasing the stability of colloidal dispersions of polymer nanostructures. This study evaluates the impact of four emulsifiers on the characteristics of polyurethane hollow structures used as drug delivery system. RESULTS Polyurethane (PU) structures with high stability and...

This paper evaluates the role of minor component polybenzoxazine (PB) on shape-memory properties of polyurethanes (PU) with glassy and crystalline soft segments. The polymer compounds were prepared in two steps. In the first step, benzoxazine, polyurethane pre-polymer, and chain extender butanediol (BD) were mixed into a solution followed by chain-extension of the pre-polymer with BD. In the se...

Phosphorus modified polyurethane/acrylic hybrid dispersions were prepared for flame retardant transparent wood coatings. The polymerisation was carried out in three steps. In the first one, polyurethane synthesised using an acrylic monomer as solvent. second step involved water addition that promoted phase inversion and lastly, part polymerised. phosphorous compounds covalently linked to a phos...