Synthesis of Vanillin-Based Polyimine Vitrimers with Excellent Reprocessability, Fast Chemical Degradability, and Adhesion

Abstract

A series of biobased polyimine vitrimers was synthesized by condensation between a dialdehyde or trialdehyde derived from vanillin and a commercial biobased aliphatic amine. The structure, thermal stability, mechanical properties, and reprocessability of vitrimers with different crosslinking degrees were investigated. The results indicated that the glass transition temperature (T g ) of vitrimers increased with the increase of cross-linking density. In addition, the vitrimers showed good malleability and recyclability even with high cross-linking degree based on fast imine metathesis. The degradation test of polyimine vitrimers suggested that the decomposition rate increased with the rising temperature, and the vitrimer degraded rapidly in 0.1 M HCl aqueous solution. After acid degradation, the aldehyde monomer was precipitated, and it can be reused to prepare a vitrimer to realize the closed-loop cycle. Finally, the biobased polyimine vitrimers can be used as adhesives, and the shear tensile strength showed that the bond strength of the vitrimer was up to 6.79 MPa.

Fully Biobased Vitrimers: Future Direction toward Sustainable Cross‐Linked Polymers

“…The only example combining vanillin derivatives with a biobased amine, i.e., Priamine, was described by Liu and coworkers. [ 158 ] Vanillin‐derived poly(aldehydes) were synthesized by reaction of 2 equivalents of vanillin with 1.3‐dibromopropane ( Ad1,Figure ) and 3 equivalents of vanillin with phosphorous oxychloride ( Ad2, Figure 19). Polyimine networks were produced under catalyst free conditions by reaction with Priamines of different grades ( Am1 , Figure 14) with a 1 to 1 amine:aldehyde ratio.…”

Malleable and recyclable imide–imine hybrid thermosets: influence of imide structure on material property

“…Furthermore, all the polymers showed high tensile strength (58-79 MPa) and tensile modulus (1.79-2.49 GPa), which are comparable to many existing polyimides (tensile strength 70-100 MPa, tensile modulus 1.5-3.0 GPa) 29 but superior to many polyimines 25,26,[37][38][39][40] . These results indicate that the hybridization by integrating the imine bond into the polyimide backbone does not adversely lead to reduction in mechanical properties of polyimides.…”

Debondable adhesives and their use in recycling

“…203 Another natural product used for debondable adhesives is vanillin. 204,205 Poly(imines), based on vanillin, have shear strengths up to 6 MPa, and may also display other properties such as antifungal activity or conductivity. Degradation of these adhesives can be achieved rapidly using 0.1 M HCl, or dynamic imine exchange at elevated temperatures.…”