Preparation and Properties of Polyether Aliphatic Polymerized Amide as a Vegetable Oil-Based Epoxy Curing Agent

Abstract

An epoxy curing agent polyether aliphatic polymerized amide (PEAPA) was synthesized using epoxy fatty acid methyl ester and diethylenetriamine. The Fourier transform infrared spectra and 1 H NMR analysis indicated successful synthesis of PEAPA. Gel permeation chromatography showed a high degree of polymerization. The obtained PEAPA was used to cure E51 epoxy resin and partially replace rigid 1,3-cyclohexanediamine curing agent. A series of epoxy resins with varying rigidities were prepared. The mechanical and thermal properties of the materials were analyzed. Mechanical property tests showed that the tensile strength and hardness of the materials decreased gradually with increased PEAPA content. However, elongation at breaks of the prepared materials increased with increased PEAPA content. Micromorphological investigation indicated excellent compatibility between PEAPA and the curing system. Furthermore, a dynamic mechanical thermal analysis demonstrated that the glass transition temperature of the epoxy resin decreased with increased PEAPA content. Thermal stability, while still excellent, decreased slightly with the addition of PEAPA. At the primary weight loss stage, initial decomposition temperatures for all resins were above 330 °C.

Synthesis of a hyperbranched polyamide oligomer containing DOPO for simultaneously enhancing the flame retardance and glass transition temperature of epoxy resin

“…The storage modulus ( E' ) and loss tangent (tan δ) curves as a function of temperature for epoxy resin samples with different content of HPD are presented in Figure 13. All tan δ curves show a single peak, illustrating that HPD is miscible with the curing systems 37 . The peak temperature of tan δ curves is chosen as the glass transition temperature ( T g ).…”

Synthesis and curing properties of castor oil‐based triglycidyl ether epoxy resin

“…As can be seen from Figures 6 and 7, at low temperatures, the storage modulus of the cured blends incorporating the products were higher than that of E‐51. As the temperature rose, the frozen segment structure began to relax, so that the storage modulus of the splines decreased 31 . On account of the long flexible chain structures which improved the chain sliding ability of the curing systems, the molecular chain of the curing component required less energy to relax, and the corresponding tanδ peaks temperature (T g ) were lower than that of neat E‐51, representing the glass transition temperature decreases 32 .…”

“…On the contrary, with the temperature keeping rising, T 50% and residual carbon ratio of the mixed cured products were even higher than E‐51. This could be explained that crosslinking density of the system increased after the product is incorporated, which correspondingly improved thermal stability 31 …”

Tung Oil-Derived Epoxy Vitrimers with High Mechanical Strength, Toughness, and Excellent Recyclability

“…Plant oils are excellent materials to prepare flexible toughening agents since their long aliphatic chains are excellent units for toughening DGEBA thermosets. − Additionally, these natural materials are renewable, and making full use of them is a way of sustainable development. There are some reports that plant oil derivatives were synthesized and used as curing agents and indeed DGEBA cured with these curing agents exhibits favorable toughness while strength is sacrificed greatly. − Yi et al prepared a soybean oil derived amine and used it to cure DGEBA. According to their reports, although the elongation at break of the DGEBA thermoset may reach 13.2%, its tensile strength is just 15.54 MPa .…”

“…There are some reports that plant oil derivatives were synthesized and used as curing agents and indeed DGEBA cured with these curing agents exhibits favorable toughness while strength is sacrificed greatly. − Yi et al prepared a soybean oil derived amine and used it to cure DGEBA. According to their reports, although the elongation at break of the DGEBA thermoset may reach 13.2%, its tensile strength is just 15.54 MPa . Mao et al cured DGEBA with a castor oil-derived dicarboxylic acid, but the tensile strength of the prepared curing sample is just 0.32 MPa .…”