writer：Qingyu Zhang Wenjia Wang Xiaoyu Gu Hongfei Li Xiaodong Liu Jun Sun Sheng Zhang
keywords：polylactic acid, flame retardancy, toughness
source：期刊
specific source：Polymer Composites, 2018.DOI:10.1002/PC. 24764
Issue time：2018年
Nowadays, numerous works have been undertaken to improve the fire resistance of polylactic acid (PLA). However, the presence of flame retardant usually shows a great destruction on the mechanical properties of PLA matrix, especially the toughness. This paper presents a new approach to simultaneously enhance both the flame retardancy and toughness of PLA by incorporating polyurethane-microencapsulated ammonium polyphosphate (MCAPP). The prepared MCAPP was blended with PLA by melt compounding to prepare PLA/MCAPP composites. The results indicated that the introduction of 15% MCAPP increased the limiting oxygen index of PLA composites from 19.3% to 28.3%, upgraded the UL-94 rating from no rating to V-0, and decreased the peak heat release rate from 464.2 to 332.2 kW/m2. Even though the tensile strength of PLA composites was decreased to 53.8 MPa, the toughness was significantly improved, with elongation at break lengthened to 40.8% and notched impact strength increased to 2.95 kJ/m2. The possible mechanisms for both flame retardancy and toughness were also discussed.