Synthesis of nanophase‐separated poly(urethane‐co‐acrylic acid) network films and their application for magnetic nanoparticle synthesis

Abstract

Poly(urethane-co-acrylic acid) films were synthesized by the copolymerization of urethane acrylate nonionomer (UAN) and acrylic acid (AA) under different conditions. Poly(urethane-co-acrylic acid) films exhibited very different mechanical properties, attributed to the microstructural difference with the type of solvents used in the film preparation. The film synthesized using UAN/AA/ water mixture had a relatively highly nanophase separated structure compared to that of the other films prepared using UAN/AA/dioxane mixture, resulting in higher mechanical property and glass-transition temperature. The nanostructural differences could be also confirmed by atomic force microscopy measurements. Magnetic nanocomposite films synthesized based on UAN/AA/water and UAN/AA/dioxane mixtures showed different sizes of magnetic nanoparticles, attributed to the differences of size of hydrophilic nanodomains. The higher the degree of nanophase separation within poly(urethane-co-acrylic acid) films, the larger the size of hydrophilic nanodomains, resulting in formation of larger nanoparticles.

Physicochemical Properties of Modified Starches Obtained by Anti‐Solvent Precipitation Containing Anthocyanins from Jambolan (Syzygium cumini) Fruit

“…[ 10 ] An alternative to improve the physicochemical properties of native starches is to modify them by means of chemical, physical, or enzymatic treatments. [ 10–12 ] The anti‐solvent precipitation method is a chemical treatment where the starch granules are hydrolyzed by heating the biopolymer in the presence of an acid or alkaline solution, followed by the starch precipitation after the addition of ethanol dropwise to the first solution. [ 13 ] Recently, this method has been used to retain and stabilize bioactive compounds such as curcumin, catechin, quercetin, and anthocyanins (ACNs) on the modified starches.…”

In vitro Performance of Nano-heterogeneous Dentin Adhesive

“…One study on silicon oxycarbide (SiOC) glasses claimed that the chemical durability in alkaline and hydrofluoric acid solutions decreased as the amount of phase separation increased (Soraru et al , 2002). Another study on magnetic nanocomposite films, synthesized by the copolymerization of urethane acrylate non-ionomer and acrylic acid in different solvents, reported a relatively highly nanophase-separated structure, resulting in improved mechanical properties and an increased glass-transition temperature (Kim et al , 2004). In contrast, the results presented here show that a high degree of heterogeneity at the nano-scale is associated with poor mechanical durability in model dentin adhesives.…”