Performance and Thermal Analysis of Aluminium Oxide …

Synthesis of Water-soluble Polymers Bearing Thermodegradable Aprotic Onium ..
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Copy the following to cite this URL: Jamaludin AN

In this study, gallic acid glycidylation was performed by slightly modifying the two-step chemical synthesis reported by Aouf et al. (2013). Tri- and tetra-glycidyl ethers of gallic acid were obtained, and their chemical structures were characterized. These bio-based epoxides were used to formulate three different model systems as curing agents, a stiff cycloaliphatic primary amine, isophorone diamine (IPDA), and a flexible polypropylene oxide amine, Jeffamine D-230 (DPG). These renewable epoxides were homopolymerized using N,N-dimethylbenzylamine (BDMA) as an ionic initiator (Dell’Erba and Williams 2006). The thermal, rheological, and mechanical properties of the gallic acid-based epoxy resins were characterized and compared with standard DGEBA-based formulations. The results showed that the GEGA structure is suitable to replace BPA-based epoxy resins.

Functionalization of graphene with grafted polyphosphamide for flame retardant epoxy composites: synthesis, flammability and mechanism
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B, Anithambigai P, Shanmugan S, Mutharasu D

An aromatic epoxy monomer, formed by glycidylation of gallic acid, was crosslinked by adopting different curing agents to obtain bio-based, crosslinked resins with suitable engineering properties. Specifically, tri- and tetra-glycidyl ether of gallic acid (GEGA) were obtained using a two-step synthesis. These bio-based monomers were cured in the following three epoxy formulations: a stiff cycloaliphatic primary amine, isophorone diamine, and a flexible polypropylene oxide amine (Jeffamine D-230). Next, the homopolymerization of GEGA was studied using an ionic initiator, N,N-dimethylbenzylamine, and a complex curing mechanism highlighted by calorimetric and mass spectra analysis. Calorimetric and rheological measurements were used to compare the curing behavior of the studied GEGA-based formulations. Mechanical properties of the gallic acid-based epoxy resins were comparable with those of standard epoxy resin formulations, based on di-glycidyl ether of bisphenol A. Thermogravimetric analysis of cured samples showed a relevant char content at high temperatures.

Nanocomposites: synthesis, structure, properties and new application opportunities
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An aromatic epoxy monomer, formed by glycidylation of gallic acid, was crosslinked by adopting different curing agents to obtain bio-based, crosslinked resins with suitable engineering properties. Specifically, tri- and tetra-glycidyl ether of gallic acid (GEGA) were obtained using a two-step synthesis. These bio-based monomers were cured in the following three epoxy formulations: a stiff cycloaliphatic primary amine, isophorone diamine, and a flexible polypropylene oxide amine (Jeffamine D-230). Next, the homopolymerization of GEGA was studied using an ionic initiator, N,N-dimethylbenzylamine, and a complex curing mechanism highlighted by calorimetric and mass spectra analysis. Calorimetric and rheological measurements were used to compare the curing behavior of the studied GEGA-based formulations. Mechanical properties of the gallic acid-based epoxy resins were comparable with those of standard epoxy resin formulations, based on di-glycidyl ether of bisphenol A. Thermogravimetric analysis of cured samples showed a relevant char content at high temperatures.

Ketone or aldehyde synthesis by acylation - Organic …
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