A temperature‐responsive polyurethane and its biocompatible and biodegradable nanohydrogels with uniform cross‐linking networks

Abstract

We prepared a temperature‐responsive polyurethane (PU) with a coil‐to‐globule transition temperature of 36°C in aqueous media, by using polyethylene glycol‐4,000 (PEG‐4000), polycaprolactone diol‐1,000 (PCL‐1000), diphenylmethane diisocyanate‐50, and hydroxyethyl acrylate. Nanohydrogels were synthesized from temperature‐responsive PU through precipitation polymerization without employing a crosslinker. Due to the unique molecular structure of temperature‐responsive PU, PU nanohydrogels have uniform cross‐linking networks resulting in narrow volume phase transition temperature range, showing sensitive temperature responsiveness. Additionally, PEG and PCL segments provide PU nanohydrogels excellent biocompatibility and biodegradability, respectively. POLYM. ENG. SCI., 59:1517–1523 2019. © 2019 Society of Plastics Engineers

Multifunctional properties optimization and stimuli‐responsivity of shape memory polymeric nanoarchitectures and applications

“…Meanwhile, a versatile range of studies have been conducted on SMP and nanoarchitectures recently with versatile enhanced properties for multifunctional applications. [ 98–180 ]…”

Polyurethane (PU) based multifunctional materials: Emerging paradigm for functional textiles, smart, and biomedical applications

“…They incorporated it to prepare a nanohydrogel with a substantially improved uniformity in crosslinking and demonstrating temperature stimulated coil to globule transition in aqueous medium 208 . Yi et al reported a three‐dimensional PU sponge that showed temperature stimulated smart super wettability applicable in the separation of water–oil 209 . In case of water‐stimulated PUs the functionality can be triggered by water, moisture or any aqueous medium due to the plasticizing effect of the water.…”

“…208 Yi et al reported a three-dimensional PU sponge that showed temperature stimulated smart super wettability applicable in the separation of water-oil. 209 In case of water-stimulated PUs the functionality can be triggered by water, moisture or any aqueous medium due to the plasticizing effect of the water. This results in shape modification and this phenomenon can be accelerated even more with the help of a water soluble ingredient.…”

Solid–solid phase‐change materials cross‐linked by carbon quantum dots: Address leakage and high super‐cooling degree simultaneously

“…Among them, PEG is particularly attractive because of its beneficial merits, such as nontoxicity, good biocompatibility, selective molecular weight, tunable phase‐change temperatures, excellent chemical, and thermal stability. Specifically, the hydroxy groups at the chain ends endow PEG with good reactivity to many compounds 4,14,15 …”

“…Specifically, the hydroxy groups at the chain ends endow PEG with good reactivity to many compounds. 4,14,15 In general, there are two main defects that largely restrict the large applications of PEG for thermal energy storage, namely leakage and high super-cooling degree. 4 The leakage of melting PEG may pollute devices and environmental, while the high super-cooling degree leads to hysteresis of energy discharging and hampers the full releasing of stored energy.…”