The aim of this study was to examine the use of renewable diphenolic acid (DPA) as starting materials together with benzylamine and paraformaldehyde for the synthesis of novel polybenzoxazine resin with low curing temperature. The monomer structure was confirmed by 1 H and 13C nuclear magnetic resonance (NMR) spectroscopy, and Fourier transform infrared (FTIR) spectroscopy. | Journal of Science and Technology 55 (1B) (2017) 63–69 SYNTHESIS OF BENZOXAZINE MONOMER WITH LOW CURING TEMPERATURE FROM RENEWABLE DIPHENOLIC ACID, BENZYLAMINE AND PARAFORMALDEHYDE Cao Xuan Viet 1, *, Tran Minh Hoan 1, Nguyen Thi Minh Nguyet 2 1 Department of Polymer Materials, Faculty of Materials Technology, HCMUT–VNUHCM 268 Ly Thuong Kiet Street, District 10, Ho Chi Minh City, Vietnam 2 Materials Technology Laboratory (MTLab), HCMUT–VNUHCM 268 Ly Thuong Kiet Street, District 10, Ho Chi Minh City, Viet Nam * Email: caoxuanviet@ Received: 30 December 2016; Accepted for publication: 3 March 2017 ABSTRACT The aim of this study was to examine the use of renewable diphenolic acid (DPA) as starting materials together with benzylamine and paraformaldehyde for the synthesis of novel polybenzoxazine resin with low curing temperature. The monomer structure was confirmed by 1 H and 13C nuclear magnetic resonance (NMR) spectroscopy, and Fourier transform infrared (FTIR) spectroscopy. Differential scanning calorimetry (DSC) was also used to study crosslinking behavior of synthesized material. The benzoxazine monomer exhibited low exothermic peak with the onset around 162 °C, which is significantly lower than conventional benzoxazines derived from bisphenol A. The presence of carboxyl groups in monomer structure is responsible for the low polymerization temperature of this monomer. Keywords: diphenolic acid, renewable, bisphenol A, benzoxazine. 1. INTRODUCTION Currently, the use of petroleum based feedstock for the manufacture of polymeric materials leads to worldwide problems such as increasing CO2 concentrations in the atmosphere, global warming, and other environmental concerns about waste [1]. These problems have encouraged the scientific community to develop and commercialize new bio–based products that can reduce the dependence on fossil fuels and minimize the negative environmental effects while they can be less expensive and better performing. The use
