Exploration of Poorly Recognized Advantages of Supply Chain Sustainable, Various Aliphatic Multiamine-Based Polybenzoxazines
Year: 2025
Type: article
Abstract: Aliphatic amine-based viscous benzoxazine resins that are liquid at or near room temperature have a great potential for their easy processability, and easy accessibility of raw material, which will play a significant role in the large-scale industrial applications. In this paper, eight aliphatic benzoxazines are synthesized by the traditional Mannich reaction under solventless conditions, using linear diamines, branched diamines or a triamine and cycloaliphatic diamines with eugenol and paraformaldehyde. A recycling sample preparative size exclusion chromatography (SEC) is used to obtain purified products. 1H and 13C nuclear magnetic resonance (NMR) spectroscopy, and Fourier transform infrared (FTIR) spectroscopy are employed to study the molecular structure of all the aliphatic amine-based benzoxazines. Two exothermic peaks are commonly observed by differential scanning calorimetry (DSC) and are assigned to the oxazine ring-opening and eugenol allyl group polymerizations as well as degradation of allyl group in the eugenol part. The glass transition temperatures (Tg) of all the aliphatic amine-based polybenzoxazines are evaluated by DSC analyses of polymers. The activation energy of the polymerization is determined by DSC at different heating rates from 2°C/min to 20°C/min and calculated by the Kissinger and modified Ozawa methods. In addition, the thermal degradation and flammability properties of polymer are monitored by thermogravimetric analysis (TGA) and micro combustion calorimetry (MCC), respectively. Among all the aliphatic amine-based benzoxazines, cycloaliphatic amine-based benzoxazine (EU-1,2dch) polymers show the best thermal stability and the highest Tg, while tris-functional amine-based benzoxazine (EU-tapa) shows the greatest anti-flammability and the lowest Tg due to their unique structures.
Source: ACS Omega
Authors: He Xia, Faiza, Pablo Froimowicz, Maria Laura Salum, Mitchell Smith, Jennifer Carter, Hatsuo Ishida
Institution: Case Western Reserve University
Language: English
Topic: Epoxy Resin Curing Processes
Subfield: Mechanical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,935
OpenAlex ID: W4408172645