Study of the thermal degradation of benzene-containing glycerol carbonate derivatives by a combined TG–FTIR and theoretical calculation

• Published in: Thermochimica acta 2017-08, Vol.654, p.179-185
• Main Authors: Liu, Jing, Li, Rujuan, Guo, Mengya, Tao, Hairong, Sun, Donglan, Zong, Chengxing, Liu, Chunjing, Fu, Fengzhi
• Format: Article
• Language: English
• Subjects: Bond dissociation energy; Glycerol carbonate derivatives; Polysubstitution; TG–FTIR; Thermal stability
• ISSN: 0040-6031; 1872-762X
• DOI: 10.1016/j.tca.2017.05.021

•Two new glycerol carbonate derivatives were designed and synthesized.•The thermal stability and pyrolysis of both compounds were explored by TG–FTIR.•The bond dissociation energy was calculated to explain the pyrolysis process.•The influence of polysubstitution of benzene on the thermal stability was studied. We recently found that the introduction of benzene ring as connection block improved the thermal stability of glycerol carbonate derivatives. To further explore how polysubstitution on benzene influences their thermal stability, another two derivatives, benzene-1,3,5-tricarboxylic acid tris-(2-oxo-[1,3]dioxolan-4-ylmethyl) ester (BATE1) and benzene-1,2,4,5-tetracarboxylic acid tetrakis-(2-oxo-[1,3]dioxolan-4-ylmethyl) ester (BATE2), were synthesized and characterized by a combined TG–FTIR and theoretical calculation. TG results showed that both BATE1 and BATE2 had three weight loss stages. FTIR spectra of evolved gases and the bond dissociation energy for the two compounds indicated that during the pyrolysis process, the CC, CO bonds of five-membered cyclic carbonate fractured preferentially to produce volatile carbonates and CO2, and then the nearby CO bond of esters continued to crack to produce more fragments. Finally, benzene ring still remains in the solid pyrolysis products. Therefore, improving the thermal stability of compound cannot be achieved simply by increasing the number of substituents on the benzene ring.