Guowen Ran, Xiaodong Liu, Jia Guo, Jun Sun, Hongfei Li, Xiaoyu Gu*, Sheng Zhang*. Improving the flame retardancy and water resistance of polylactic acid by introducing polyborosiloxane microencapsulated ammonium polyphosphate. Composites Part B: Engineering. 2019, 173, 106772

https://doi.org/10.1016/j.composite**.2019.04.033

Abstract

Ammonium polyphosphate (APP) was respectively microencapsulated with polysiloxane (Si) and polyborosiloxane (BSi), and then were introduced into polylactic acid (PLA) to synchronously improve the flame retardancy, water resistance and mechanical properties of PLA composite. Fourier transform infrared (FTIR)/energy dispersive spectrometer (EDS) ****ysis and scanning electron microscopy (SEM) observation confirmed that the APP was successfully microencapsulated with Si and BSi, respectively. The flammability evaluation for the PLA/5%BSi-APP samples by limit oxygen index (LOI), UL-94 vertical burning test and cone calorimeter test (CONE) revealed the LOI value achieved to 26.7%, UL-94 grade reached up to V-0, and the peak heat release rate (HRR) was decreased significantly. The microencapsulation of APP also improved the compatibility of APP with PLA, resulting in better mechanical properties than control APP contained composites under the same loading. The water resistance of PLA composite was also significantly improved by the introduction of microencapsulated APP.