Aliphatic Diamide as Novel Asphalt‐Modified Epoxy Curing Agent for Enhanced Performance

Abstract

Adipamide used as the curing agent of asphalt-modified epoxy resin was synthesized by esterification and ammonolysis, and its chemical structure was confirmed by the Fourier transform infrared spectroscopy (FTIR), 1 H and 13 C nuclear magnetic resonance ( 1 H NMR and 13 C NMR) analysis. The thermal stability, Vicat softening temperature, tensile strength, and Shore D hardness of the cured asphalt-modified epoxy resin were studied by thermogravimetric analysis (TG), Vicat softening tester, tensile tests, and Shore D plastic hardness tester, respectively. The surface morphology of epoxy resin tensile fracture was also observed by scanning electron microscopy (SEM). The Vicat softening temperature of cured epoxy resin decreased from 95 to 64°C with increasing modified asphalt (MA) contents from 0 wt.% to 25 wt.%. The maximum tensile strength of cured epoxy resin reached 45.4 MPa when MA content was 5 wt.% of the whole resin. The Shore D hardness slightly decreased from 86 D to 79 D as the MA was enhanced from 0 wt.% to 25 wt.%. TG results displayed that the thermostable temperature of cured epoxy resin was higher than 280°C.

Novel nanocomposites based on epoxy resin and modified magnesium hydroxide: Focus on flame retardancy and mechanical properties

“…And different degrees of enhancement of flexural strength and flexural modulus can be clearly seen by adding flame retardants of various formulations into EP composites. It is shown that the interactions between the AM‐MEL with active amine groups as crosslinking dots and the EP were evidently enhanced by the covalent bonds . In the S3 sample, the incorporation of 20 wt% AM‐MEL supplies simultaneous enhancements to flexural strength and flexural modulus to 45.5 ± 2.8 MPa and 2583.2 ± 71.4 MPa, respectively, which were not satisfactory compared with those of S1.…”

Application of Epoxy‐Asphalt Composite in Asphalt Paving Industry: A Review with Emphasis on Physicochemical Properties and Pavement Performances

“…A yellow liquid state (60°C) curing agent, aliphatic diamine, was synthesized in the laboratory by Cong et al [20] to improve elongation and delay rapid viscosity growth. Jiang et al [28] synthesized adipamide through esterification and ammonolysis (see Figure 4) to overcome the strong volatilization, high toxicity, and skin irritation of the traditional amine-based curing agents. It was confirmed to have…”

“…However, in practice, this will require a special vehicle equipped with an induction coil passing over the pavement after compaction. [28]. 4 Advances in Materials Science and Engineering…”

Low-Viscosity Eutectic Hardeners for More Sustainable Cross-Linking Conditions

“…However, to promote the cross-linking reaction and create a thermally and mechanically stable network, bioresin must be reacted with a curing agent so-called “hardener” to spread out the overall functionality in a wide temperature range, yielding highly branched networks and a sufficiently high glass transition temperature ( T g ), which is a direct indicator for the application domain. There are a growing number of coreactants from aliphatic, cycloaliphatic, to polyfunctional amine, amide, and anhydride that are used depending on the targeted performances of the final thermoset polymer. ,,− They are important key reactants due to their nucleophilic nature that grants high reactivity toward the epoxy ring, allowing them to be active at room temperature bearing low-viscosity and low-cost formulation, resulting in polymers with a high glass transition temperature. ,,, Most of these routinely employed hardeners are derived from petroleum-based feedstocks, and some of them are toxic and can present health issues. Furthermore, the risk of toxicity can stand inside the cured system, corresponding to the unreacted curing agent trapped in the polymeric network that stands in contrast to the concepts of green chemistry. , One of the commercially available, petroleum-based curing agents is hexahydrophthalic anhydride (HHPA) and its cured epoxy system showed a relatively high T g , which depends on the selected monomer.…”