Phytic acid and amino acid belonging to the biomass material have a wide range of sources in nature. In this work, three kinds of basic amino acids, which are arginine, lysine, and histidine, were used to prepare different bio-based phytic acid−basic amino acid salts (PaArg, PaLys, and PaHis) via a saltforming reaction. After the incorporation of PaArg, PaLys, and PaHis into polypropylene (PP), PaArg showed a higher efficiency than PaLys and PaHis in endowing PP with flame retardancy. At 22 wt % PaArg, the limiting oxygen index (LOI) value of functional PP was 26.0%, and its UL-94 rating reached V-0 in the vertical burning test. In the fire hazard test, PaLys showed a higher efficiency than PaArg and PaHis in reducing the fire hazard of PP during burning. The peak value of the heat release rate for PP containing 25 wt % PaLys was decreased by 70.7% compared with that of PP, and its fire growth rate was reduced by 86.9%. Analysis on the fire-safety mechanism revealed that the high char-forming rate and the quality of the residue dominated the superior flame-retardant efficiency of PaArg in UL-94 and LOI tests; high strength of the formed char layer, diluting effect of nonflammable gases, and incomplete combustion action led to the superior efficiency of PaLys in decreasing the fire hazard of PP. This work confirms that fully bio-based phytic acid−basic amino acid salt based on the accurate molecular design may endow PP with fire safety under different burning scenes.

No abstract

No abstract

In the functionalization of transparent polycarbonate (PC), the addition of additives often results in damage to the transparency of polycarbonate, thereby limiting its application in the field with a high transparent requirement. In this study, sulfonate-group-containing polymeric polyamide SK was synthesized and employed as a functional agent for PC. The results demonstrated that the SK significantly improved the fire safety of PC. 1.0 wt % SK endowed PC with a UL-94 V-0 rating and a limiting oxygen index of 30.4%; compared with that of neat PC, the maximum smoke density (Dsmax) and the peak of heat release rate (PHRR) for 1.0 wt % SK-blended PC were decreased by 21% and 39%, respectively. More importantly, the transparency of the original PC was maintained at 86.4% after incorporation of 1.0 wt % SK, showing only a slight reduction. Here, excellent flame retardancy is ascribed to the synergistic effect of SK-caused physical cross-linking and carbonization. While, high transparency is attributed to the amorphous nature of SK and its good compatibility with PC. This work demonstrates that SK is an efficient polymeric functional agent for fabricating transparent and flame-retardant PC and provides another idea for designing a sulfonate-group-containing flame retardant differing from traditional sulfonates for PC.