Catalyst-Free Self-Healing Bio-Based Polymers: Robust Mechanical Properties, Shape Memory, and Recyclability

Abstract

The poor mechanical properties and disadvantages of catalysts limit the application of self-healing materials. To address these issues, catalyst-free self-healing bio-based polymers (AESO−EMPA polymers) with robust mechanical properties were prepared using epoxidized maleopimaric anhydride (EMPA) and aminated epoxidized soybean oil (AESO). The AESO−EMPA polymers are recyclable and exhibit self-healing and shape memory because of the dual-dynamic network of multiple H-bonds and dynamic ester bonds in the structure. Under the synergistic catalysis of the tertiary amines and hydroxyl groups originated from the polymers, the polymers in this study achieve network rearrangement without the need for additional catalysts. The polymers also exhibit excellent mechanical properties with a tensile strength of 29.1 ± 0.25 MPa and a T g of 80.2 °C owing to the unique rigid backbone of rosin and the dual-dynamic network. The AESO−EMPA polymers can be used as reusable adhesives and exhibit excellent shear strength and repair rates.

Readily recyclable, high-performance catalyst-free tung oil-derived vitrimer and carbon fiber reinforced composites

“…where τ is the stress relaxation time; Ea is the activation energy of the transesterification reaction; R is the gas constant; A is a pre-exponential factor. Based on this equation, the activation energy of DGEBA/TGDOM-TTMA is 92.37/106.09 kJ•mol -1 , which is comparable to the values of DTERstype vitrimers (69-150 kJ•mol -1 ) [1,31,37,38]. In addition, the activation energy of DGEBA-TOMA (SI, Fig.…”

“…The cross-linked network structure of DGEBA/TGDOM-TTMA contains plentiful ester bonds, hydroxyl groups, and tertiary amine, which can change their topology at high temperature via DTERs without extra catalyst [31]. The self-healing performance of DGEBA/TGDOM-TTMA was investigated through surface scratch testing (Fig.…”

“…These findings suggest that the TO-based vitrimers exhibit excellent thermal healing performance without external force and catalyst. This main reason is that the molecular structure promotes the DTERs and the dissociation of H-bonds at high temperature, which can affect the movement of polymer chain segment, resulting in rapid self-healing of the vitrimers [1,31]. The triple-shape-memorized performance is typical of vitrimers, and shape-memory-assisted selfhealing is commonly observed in biological systems, such as wound closure in leaves [34].…”

Design of ester crosslinked rubber with high dynamic properties by increasing dynamic covalent bond density

“…12 So far, transesterification, [13][14][15][16][17][18][19] disulfide exchange, 20,21 boronic ester exchange, [22][23][24][25] imine metathesis, [26][27][28][29] urethane exchange 30 and so on have been used to develop various associative CANs. Developing new DCBs, [31][32][33] increasing the concentration of DCBs, 34 selecting suitable catalysts 15,[35][36][37] and designing ingenious neighboring group participation [38][39][40][41][42][43][44][45] are alternative schemes to achieve high efficiency and fast dynamics of CANs. Leibler et al initially remolded epoxy networks by introducing zinc catalysts into classic thermoset epoxy resins to stimulate transesterification.…”

White Light Emissive Vitrimers for Phosphor-free Light Emitting Diode Encapsulations

“…To realize a fast exchange reaction and remarkable reprocessing capability for vitrimers, a highly e cient catalyst such as a Lewis acid, transition metal, strong base, or nucleophilic catalyst is frequently added into vitrimers to lower the exchange reaction's activation energy [28][29][30] . However, the extra catalyzers can induce many problems, including catalyst aging, deterioration of the material properties over time and the toxicity of the catalyst [31][32][33][34] . The use of a tertiary amine embedding in the crosslinked network as an internal catalyst has recently been shown to accelerate the transesteri cation reactions [34][35][36][37][38][39] .…”