A Novel Ionic Conductive Polyurethane Based on Deep Eutectic Solvent Continuing Traditional Merits

Abstract

Artificial intelligence (AI) has become increasingly popular along with the development of the bionic neural system. Ionic conductors play an important role in the AI system due to the ability of bionic sensing and signal transporting. Traditional low-polarity elastomers possess outstanding mechanical strength and stability, such as polyurethane, which is difficult to be directly endowed with ionic conductivity without impairing its properties. Herein, we have first put forward a new approach to synthesize a liquid-free ionic conductive polyurethane (CPU) through one-step copolymerization between a green deep eutectic solvent (DES) and a prepolymer of polyurethane. The as-prepared CPU can retain the native properties of the traditional polyurethane (PU) such as the homogeneous phase, ease of molding, high transparency (about 93.3%), and excellent mechanical properties. By introducing the DES as the covalent cross-linking agent and ionic conductor at the same time, the CPU also has fine ionic conductivity (3.78 × 10–5 S cm–1), environmental resistance like anti-freezing (−20 °C), and solvent resistance. Based on the excellent conductivity and mechanical strength, the flexible CPU can be applied as a sensing element in pressure sensors. The CPU-based sensor has presented long-term stability, high sensitivity, and wide-ranging response (0.17–3.28 MPa) to the applied pressure, which will be suitable for the industrial demands for practical applications.

Synthesis of completely solvent-free biomedical waterborne polyurethane with excellent mechanical property retention and satisfactory water absorption

“…While the UV transmittance of MWPU1.5 did not change significantly at approximately 60%, there was a white membrane on the MWPU1.5 film. 63 The internal cross-linked structure of the MWPU1.5 membrane is looser and absorbs more water, and water absorption induces membrane phase separation, resulting in a white membrane, 1 while the MWPU1.6 membrane is not affected by water.…”

Toward mechanically robust self-healing polyurethanes using dynamics chemistry

“…32 Reproduced with permission from ref. conductivity, 73 and hydrophilicity. 74,75 Yao et al 76 constructed a self-healing waterborne PU with ionic bond and hydrogen bond coordination, which used (N-acrylylglycine) diols and dimethylol propionic acid as the chain extender and PCL as the soft segment.…”

“…67 The ionic interaction in the PU is generally introduced through the blending of ionic liquids or the reaction of ionic chain extenders. While providing the self-healing properties of PUs, the ionic bond usually brings antibacterial properties, 68–70 adsorption properties, 71,72 electrical conductivity, 73 and hydrophilicity. 74,75 Yao et al 76 constructed a self-healing waterborne PU with ionic bond and hydrogen bond coordination, which used ( N -acrylylglycine) diols and dimethylol propionic acid as the chain extender and PCL as the soft segment.…”

High ionic conductive, freezing-resistant and transparent polyurethane based on a novel metal ionic deep eutectic solvent

“…3(c) shows a comparison between the conductivity in our work with that of other ionconducting materials, and the results show that the present material has a relatively higher conductivity than other similar materials. [47][48][49][50][51][52][53] Considering its electrical conductivity and appropriate mechanical properties, CPU-5 was selected as a sample to be assembled into a bendable pressure sensor according to the scheme in Fig. S9 (ESI †).…”