Synthesis of self‐healing soybean oil‐based waterborne polyurethane based on Diels–Alder reaction

Abstract

In order to endow water‐based polyurethane with special functionality, vegetable oil‐based waterborne polyurethane with self‐healing properties is synthesized. Firstly, soybean oil‐based emulsifier (GA‐ESO) was prepared by epoxy soybean oil and glutaric acid without solvent and catalyst. Then, two Diels−Alder (DA) diols were prepared by the DA reaction between N,N′‐(4,4′‐methyldiphenyl) bismaleimide, 4‐maleimide phenol and furfuryl alcohol, respectively. Finally, GA‐ESO and DA diols used as the raw material was reacted with isophorone diisocyanate to synthesize a series of soybean oil‐based waterborne polyurethane with self‐healing behavior. The effects of DA diol on the properties of polyurethane films and the self‐healing process and mechanism of polyurethane membrane were investigated. The results showed that after the addition of DA diol, the particle size of polyurethane emulsion increased from 28.8 to 85.3 nm, the tensile strength was improved from 0.3 to 12.6 MPa, and the water contact angle was enhanced from 68.5° to 84.2°. In addition, it can be observed that with the addition of DAdiol, the polyurethane film had self‐healing behavior at high temperature, and the highest self‐healing efficiency can reach 100%.

Self‐healing polyurethane based on a substance supplement and dynamic chemistry: Repair mechanisms and applications

“…The heat recovery benefits of this environmentally friendly PU material can be visually demonstrated in Figure 8a. Similarly, Chen et al 63 used soybean oil‐based emulsifier and diol obtained by DA reaction as raw materials, and highly cross‐linked with isophorone diisocyanate to obtain functional waterborne PU. This environment‐friendly material is not only significantly improved in emulsion particle size, mechanical strength and water repellency after the introduction of DA reaction, but also self‐healing efficiency can reach 100% after alternating treatments of short‐range heating at 130°C and holding at 75°C for 24 h.…”

Recent Advances in Tailored Fabrication and Properties of Biobased Self-Healing Polyurethane

“…ESO possesses a higher number of reactive groups, making it a suitable replacement for polyols in the preparation of PU. 68 To endow the self-healing performance at high temperature of PU, two kinds of Diels−Alder (DA) diols were synthesized (Figure 5a) and introduced in PU as chain extenders. The resulting polyurethanes were named BFWPU and AFWPU, respectively.…”

“…(a) Synthesis process of DA diol of (i) BMI as the raw material; (ii) ATOM as the raw material. Adapted with permission from ref . Copyright 2022 John Wiley and Sons.…”

“…(a) Self-healing mechanism of BFWPU. Adapted with permission from ref . Copyright 2022 John Wiley and Sons.…”

“…Chen et al successfully prepared soybean oil-based emulsifier (GA-ESO) utilizing ESO and glutaric acid (GA) as raw materials in the absence of solvent and catalyst, replacing polyols in the preparation of PU . To endow the self-healing performance at high temperature of PU, two kinds of Diels–Alder (DA) diols were synthesized (Figure a) and introduced in PU as chain extenders.…”