2026-10-13T04:54:08Z https://api.figshare.com/v2/oai

oai:figshare.com:article/34028737 2026-09-30T03:03:29Z category_1 category_4 category_915 category_21 category_873 category_734 category_61 category_106 portal_63 item_type_6 month_year_09_2026

Amine-Structure-Regulated Vanillin-Derived Imine-Cross-Linked Networks for Reprocessable, Self-Healing, and Chemically Recyclable Thermosets Jinling Li (229265) Yaoyao Zhang (490669) Yangguang Xiang (25078121) Yanyan He (2855495) Lixiang Zhu (7489586) Yunchao Jia (15561689) Biophysics Biochemistry Physical Sciences not elsewhere classified Biotechnology Chemical Sciences not elsewhere classified Biological Sciences not elsewhere classified Developmental Biology Science Policy two reprocessing cycles renewable aromatic platform enabled thermal reprocessing combine mechanical robustness balanced mechanical performance apparent activation energies 43 × 10 31 × 10 providing functional groups loop material design flexible dm segments containing dialdehyde monomer 90 ° c 22 kj mol dynamic network construction trifunctional tam junctions structure regulation provides linked polymer networks chemical recyclability remains 2 ° c tam content raised vd ), decanediamine dynamic imine network derived imine networks derived effective cross linked networks dm ), chemical recyclability dynamic adaptability retaining 90 mol cm effective strategy design allowed derived imine network structure network rigidity network became linked polymers derived thermosets vd monomer vd content imine exchange derived cross transition temperature tensile strength tam ). systematically regulated strength recovery Developing vanillin-derived thermosets that combine mechanical robustness with repairability and chemical recyclability remains a central challenge in replacing petroleum-derived cross-linked polymers. Vanillin offers a renewable aromatic platform for this purpose because it can introduce rigidity while providing functional groups for dynamic network construction. Here, we report a series of vanillin-derived imine-cross-linked polymer networks (VD-TAM) prepared from a benzoxazine-containing dialdehyde monomer (VD), decanediamine (DM), and tris(2-aminoethyl)amine (TAM). By fixing the aldehyde/amine functional-group ratio at 1:1 and the VD content while varying the relative contributions of flexible DM segments and trifunctional TAM junctions, the network structure was systematically regulated. This design allowed the amine structure-dependent balance between network rigidity and imine-exchange dynamics to be evaluated. Increasing the TAM content raised the glass-transition temperature from 49.3 to 72.2 °C, the DMA-derived effective cross-link density from 5.31 × 10^–4 to 16.43 × 10^–4 mol cm^–3, and the tensile strength from 40.37 to 56.33 MPa, while decreasing the elongation at break from 124.47 to 7.29%. Stress-relaxation analysis confirmed thermally activated network relaxation associated with imine exchange, with apparent activation energies for macroscopic network relaxation increasing from 35.83 to 49.22 kJ mol^–1 as the network became more constrained. The dynamic imine network further enabled thermal reprocessing, shape-memory behavior, and efficient self-healing, with VD-TAM-50 showing a representative tensile-strength recovery of 93.5% after healing at 90 °C for 20 min and retaining 90.9% of its tensile strength after two reprocessing cycles. In addition, acid-triggered imine hydrolysis allowed recovery of the VD monomer, indicating a potential route toward monomer recovery and future closed-loop material design. These results demonstrate that amine-structure regulation provides an effective strategy for designing vanillin-derived imine networks with balanced mechanical performance, dynamic adaptability, and chemical recyclability. 2026-09-29T00:00:00Z Text Journal contribution 10.1021/acsomega.6c07945.s001 https://figshare.com/articles/journal_contribution/Amine-Structure-Regulated_Vanillin-Derived_Imine-Cross-Linked_Networks_for_Reprocessable_Self-Healing_and_Chemically_Recyclable_Thermosets/34028737 CC BY-NC 4.0