X. Wang, S. Y. Xuan, L. Song, H. Y. Yang, H. D. Lu and Y. Hu (2012) Synergistic Effect of POSS on Mechanical Properties, Flammability, and Thermal Degradation of Intumescent Flame Retardant Polylactide Composites. Journal/Journal Of Macromolecular Science Part B-Physics 51 255-268. [In English]
Web link: http://dx.doi.org/10.1080/00222348.2011.585334
Keywords: flame retardancy, mechanical properties, polylactide, POSS, synergistic, effect, thermal degradation, AMMONIUM POLYPHOSPHATE, POLY(LACTIC ACID), NANOCOMPOSITES, STABILITY, PHOSPHATE, STARCH, SYSTEM
Abstract: The intumescent flame retardant polylactide/polyhedral oligomeric silsesquioxane (IFR-PLA/POSS) composites were prepared via a melt blending method. The morphology of the PLA nanocomposites was assessed by transmission electron microscopy (TEM). Dynamic mechanical analysis (DMA) and tensile tests showed that the incorporation of POSS enhanced the mechanical properties of the PLA matrix. The limiting oxygen index (L01) values increased from 20.0% for neat PLA to 40.0% for PLA based on 22.5 wt% IF!? and 7.5 wt% POSS, and the latter could pass UL-94 VO rating. Thermal gravimetric analysis (TGA) showed that the thermal stability of the residual char at the later stages of the thermal degradation was significantly improved. The dynamic Fourier transform infrared (FT1R) spectra suggested that the thermally stable poly(phosphoricacid) and polysiloxane derivatives were formed during the thermal degradation process of PLA/POSS composite. The scanning election microscope (SEM) and X-ray photoelectron spectrography (XPS) indicated that the residual char offlame retardant PLA/POSS composite had a exterior layer with a compact and continual sutface, while the interior had a porous structure, which was composed of cross-linked phosphorous oxynitride and carbonized aromatic networks.