Development of Mg-Zn-Al-CO3 ternary LDH and its curability in epoxy/amine system

• Published in: Progress in organic coatings 2019-11, Vol.136, p.105264, Article 105264
• Main Authors: Karami, Zohre, Jouyandeh, Maryam, Ali, Jagar A., Ganjali, Mohammad Reza, Aghazadeh, Mustafa, Maadani, Mona, Rallini, Marco, Luzi, Francesca, Torre, Luigi, Puglia, Debora, Saeb, Mohammad Reza
• Format: Article
• Language: English
• Subjects: Aluminum; Carbonate anion; Cure Index; Curing; Differential scanning calorimetry; Epoxy; Heating; Hydroxides; Interlayers; Labeling; Layered double hydroxide; Magnesium; Nanocomposites; Zinc
• ISSN: 0300-9440; 1873-331X
• DOI: 10.1016/j.porgcoat.2019.105264

•Synthesized and characetrized Mg-Al LDH intercalated with cabonate anion, Mg-Al-CO3 LDH.•Fully characetrized Mg-Al-CO3 LDH with FTIR, TGA, and XRD analyses.•Epoxy/Mg-Al-CO3 LDH nanocomposites underwent dynamic DSC at various heating rates.•Overall, Cure Index was Poor for epoxy/Mg-Al-CO3 LDH nanocomposites irrespective of heating rate. Labeling epoxy/layered double hydroxide (LDH) nanocomposites for properties requires a priori curability estimation. The co-precipitation method was applied in synthesis of Mg-Zn-Al ternary LDH and intercalation with carbonate anion led to development of Mg-Zn-Al-CO3-LDH. The structure of developed ternary LDH was studied by XRD, FTIR and TGA/DTG analyses. Nonisothermal differential scanning calorimetry (DSC) at heating rates of 2, 5, 7 and 10 °C/min was used to evaluate the curing potential of low-filled epoxy/LDH nanocomposite by labeling them for curability. It was unraveled by the use of Cure Index that even by using well-synthesized Mg-Zn-Al-CO3-LDH ternary structure the epoxy curing was hindered, underlining the importance of curability estimation before dealing with properties of epoxy/LDH systems. It can be concluded by accepting Poor label for the studied system that although carbonate ion deposition in between galleries enlarged interlayer space it inevitably confined collision between epoxy and amine curing precursor. This negative effect was signaled by a significant fall in heat release amount of nanocomposites sample compared to the neat epoxy irrespective of heating history.