The new subamine functional bio-based epoxy monosome gives epoxy resin excellent mechanical properties, flame retardant properties and degradable properties

Keywords:
Schiff alkali catalytic degradation Dynamic co-priced thermoso-curing materials functional
background:
In recent years, due to the increasing consumption of fossil resources and traditional petroleum-based thermostate materials ecological problems and post-treatment problems, the development of bio-based high-performance thermosolytic materials has been extensively studied. However, because the introduction of functional additives or chemical structures into polymer substations often impairs other properties of thermostats, the synthesis of bio-based epoxy thermostats with excellent combined properties (mechanical, fire resistance and degradation) remains a major challenge in the field of conventional thermosostats. As research continues, the multi-functional (self-intersecting, rigid and reversible) schifflein (subamine) offers new possibilities and

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Weiqi Xie of the School of Materials Science and Engineering of South China University of Technology, etc., for the first time used natural lilac aldehyde (SH) and 1,4-butyl diamine (BDA) as raw materials, through a simple, highly selective method to synthesize all-bio-based monoploids (1,4-butyl-butyl twins (4-hydroxy-3,5-dimethylamine) di-shrink glycerin ether (SH-BDA-EP).
his findings were published in Chemical Engineering Journal.4,4 diamine diphenyl methane (DDM) as a curing agent in the course of this study, and the resulting bio-based epoxy thermostate material (SH-BDA-EP/DDM) has excellent mechanical and flame retardant properties Performance, of which bend strength is 121.8 MPa and limit oxygen index (LOI) is 39.6%, which is far superior to the common bisphenol a cyclooxythermal solid material (DGEBA/DDM). SH-BDA-EP/DDM's Schiff alkali structure has high temperature self-linking characteristics during combustion, catalyzing polymer chains to form a stable protective layer, so that SH-BDA-EP/DDM has excellent flame retardant properties. In addition, other unique features of the Schiff alkali structure (rigidity and reversibility) give SH-BDA-EP/DDM excellent mechanical properties and acid catalytic degradation.
the content of the
1.SH-BDA
added SH (16.40g, 0.09mol) and BDA (2.64g, 0.03mol) to a 500mL three-necked burn bottle containing 300ml ethanol (nitrogen conditions). Stir the mixture, heat 5h at 80 degrees C, then cool the reaction system (25 degrees C), then filter and wash the filtered residue with ethanol (3 times). Solid products dried 24h at 60 degrees C, resulting in a light brown powder SH-BDA (10.89g with a yield of 87.2%).
2.SH-BDA-EP preparation
adds TBAB (1.29g, 4.0mmol), SH-BDA (16.65g, 0.04mol) and ECH (37.01g, 0.40mol) to a 500mL three-neck bottle containing 300ml ethanol (nitrogen conditions). Stir the mixture, heat 8h at 80C, cool to 55C, slowly add the NaOH solution (40wt, 30mL) and stir 6h. The reaction system is then cooled (25 degrees C) and evaporated in a vacuum to remove the solvent. Ethyl acetate is added to the resulting product and washed with distilled water (three times). Finally, the organic layer was dried with sodium sulfate without water, and the brown oil SH-BDA-EP (19.50g with a yield of 92.3%) was evaporated by vacuum. The epoxy equivalent of SH-BDA-EP (EEW, 328.5g/mol) was measured according to ASTM D1652-11. The synthetic routes of SH-BDA and SH-BDA-EP are shown in Figure 1.
3. Preparation of the epoxy thermo-cured resin curing film
cross-curing SH-BDA-EP with DDM (where the molar ratio of epoxy group to N-H is 1:1) results in SH-BDA-EP/DDM. Mix SH-BDA-EP and DDM at 60 degrees C and degass at 60 degrees C for 20 minutes in a vacuum furnace. The mixture of SH-BDA-EP and DDM is then heated and cured by a procedure of 120 degrees C1h, 150 degrees C2h, and 190 degrees C2h, resulting in a thermosysmicated SH-BDA-EP/DDM. The curing of commonly used bisphenol A epoxy thermosteresic resins was compared with the same curing agent.
the results of
1. Signs
2, Curing Research:
3, Thermal Performance:
4, Flame retardant performance:
5, TG-FTIR analysis of gas products:
6, carbon analysis:
7, Degradation and Mechanical Properties:
Conclusion: The
research process proposes a new strategy for the functionalization of high-performance epoxy thermostate materials, giving them excellent mechanical, flame retardant and degradation properties. A new type of subamine-functional bioenoxygen monosome SH-BDA-EP was synthesized, with a bending strength of 121.8 MPa and a limit oxygen index (LOI) of 39.6% for cured bio-based epoxy thermostating material (SH-BDA-EP/DDM). Specific subamine structures also make SH-BDA-EP/DDM prone to degradation in acidic media. The results show that Schiff alkali correlation can be used in different applications by functionalizing epoxy thermostate materials, which may be suitable for other thermostate materials and provide new insights into the functional application of traditional thermosolytic materials.
:
Xie W, Huang S, Liu S, et al. Imine-functionalized biomass-derived dynamic covalent thermosets enabled by heat-induced self-crosslinking and reversible structures[J]. Chemical Engineering Journal, 2021,404:126598.