Synthesis, polymerization kinetics of 4-allyl-substituted 1,3-benzoxazine and properties of resulting polymer
writer：Yiqinq Xia, Linze Liu, Lian Wang, Rui Shi, Shuai Yan, Xingyu Zhao, Yuping Sheng, Zhi Wang
keywords：Benzoxazine; 4-Allyl-Substituted; Curing kinetics
source：期刊
specific source：Thermochimica Acta
Issue time：2022年
In this paper, a novel 4-allyl-substituted 1,3-benzoxazine (P-a-[4]ally) was successfully synthesized based on the allylation reaction of aldimines. The chemical structures of intermediates (P-1 and P-2) and P-a-[4]ally were characterized by NMR spectra, and Fourier transform infrared (FT-IR) spectra. The polymerization and curing kinetics were studied by DSC and in-situ FT-IR, and the charge densities of atoms were calculated by Materials Studio. The activation energy of the curing reaction was 108.3 kJ·mol?1 by the Kissinger-Akahira-Sunose method and 111.0 kJ·mol?1 by the Ozawa method. Thermomechanical analysis (TMA), thermogravimetric analysis (TGA), and an Agilent impedance analyzer were used to investigate the thermal and dielectric properties of poly-benzoxazine (P(P-a-[4]ally)). The results revealed that the glass transition temperature (Tg) of P(P-a-[4]ally) was 154°C, the temperature at 5% weight loss (Td,5%) was 329°C, the char yield was 21.2% at 800°C under N2, and the dielectric constant was 3.33 at 1 MHz.