Lingling Gu, Sheng Zhang, Hongfei Li, Jun Sun, Wufei Tang, Liqian Zhao, Xiaoyu Gu*. Preparation of intumescent flame retardant poly(butylene succinate) using urea intercalated kaolinite as synergistic agent. Fibers and Polymers. 2019, 20(8), 1631-1640.

DOI 10.1007/s12221-019-7999-8

Abstract

Urea (U) was successfully intercalated into Kaolinite (Kaol) and the product K-U was introduced into poly(butylene succinate) (PBS)/intumescent flame retardants (IFR) by melt blending. The structure of K-U was characterized by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The flame retardancy, thermal degradation, and combustion behavior of PBS composites were characterized by limiting oxygen index (LOI), vertical burning test to get UL-94 rating, thermogravimetric****ysis (TGA), and cone calorimeter test (Cone). With the introduction of K-U and IFR into PBS, the LOI obviously increased from 21.9 % for neat PBS to 40.1 % for composite containing 20 wt% IFR/5 wt% K-U; PBS cannot pass any UL-94 rating but the composite passed UL-94 V-0 rating. Similarly, the peak heat release rate (PHRR) in cone test decreased from 576 kW/m² to 292 kW/m². SEM results showed the char of the composite became more compact and **ooth.