Synthesis and Flame-Retardant Performance of Epoxy Resins Containing Aromatic Imine from Different Bisphenols Based on the Duff Reaction was written by Wang, Shengda;Jiang, Hanqing;Yu, Ronghua;Lou, Shenghui;Ma, Li;Liu, Jie;Tang, Tao. And the article was included in Chemistry of Materials in 2022.Reference of 620-92-8 The following contents are mentioned in the article:
A series of epoxy resins containing aromatic imine are synthesized via the Duff reaction by using various bisphenols, which show significantly reduced heat release capacity (HRC) and total heat release (THR) after curing. Compared to diglycidyl ether bisphenol A/4,4-diaminodiphenylmethane (DGEBA/DDM), the HRC and THR of phenolphthalein-based epoxy resin containing aromatic imine/DDM (BPP-E/DDM) are reduced by 87% (464 J/g K vs 58 J/g K) and 62% (30.2 kJ/g vs 11.4 kJ/g), resp. Furthermore, the BPP-E/DDM exhibits a UL-94 V-0 rating (1.6 mm) and a limiting oxygen index of 48% (3.2 mm). Compared to DGEBA/DDM in the cone calorimeter test, the peak heat release rate, THR, peak smoke produce rate, and total smoke production of BPP-E/DDM were reduced by 91% (1006 kW/m2vs 87 kW/m2), 51% (89 MJ/m2vs 44 MJ/m2), 89% (0.36 m2/s vs 0.09 m2/s), and 79% (38 m2vs 8 m2), resp. The influences of aromatic imine and the chem. structures between two benzene rings in the bisphenols on HRC and THR of the resultant epoxy thermosets are investigated. The mechanism studies show that the presence of aromatic imine in the epoxy resins completely changes the decomposition process to generate the products containing aromatic N-heterocycle, which contributes greatly to the improved char-forming ability and flame retardancy. Meanwhile the thermosets bearing carbonyl, 3-phthalidylene, and sulfonyl between two benzene rings in the bisphenols show better char-forming ability and flame retardancy among the resultant epoxy resins containing aromatic imine, due to more polycyclic aromatic hydrocarbons produced in the condensed phase. This study involved multiple reactions and reactants, such as 4,4′-Methylenediphenol (cas: 620-92-8Reference of 620-92-8).
4,4′-Methylenediphenol (cas: 620-92-8) belongs to alcohols. Under appropriate conditions, inorganic acids also react with alcohols to form esters. To form these esters, a wide variety of specialized reagents and conditions can be used. Converting an alcohol to an alkene requires removal of the hydroxyl group and a hydrogen atom on the neighbouring carbon atom. Dehydrations are most commonly carried out by warming the alcohol in the presence of a strong dehydrating acid, such as concentrated sulfuric acid.Reference of 620-92-8
Referemce:
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