聚乳酸的增韧阻燃性能

针对聚乳酸(PLA)易燃和脆性大等缺点,采用聚磷酸铵(APP)和聚乙二醇(PEG)对PLA进行了改性,同时控制PLA、APP和PEG之间的质量比例为5.7∶1.17∶1,研究了液晶聚合物(LCP)对复合材料的阻燃性能和力学性能的影响.结果表明,当添加质量分数为15%的APP时,复合材料的极限氧指数(LOI)可以达到30.1%,而仅添加相同质量分数的PEG时,复合材料达不到阻燃效果.PLA/APP/PEG复合材料相比纯PLA具有较高的残炭率.加入PEG后复合材料的断裂伸长率明显提高,而LCP的添加提高了复合材料的拉伸强度,但降低了复合材料的断裂伸长率.

Toughening and flame retardant properties of polylactic acid

Aiming at such defects of polylactic acid(PLA)as the inflammability and high brittleness, PLA was modified with ammonium polyphosphate(APP)and polyethylene glycol(PEG). Meanwhile, the weight ratio was set as 5.7(PLA)∶1.17(APP)∶1(PEG), and the effect of liquid crystal polymer(LCP)on the flame retardant and mechanical properties of composites was investigated. The results show that when the mass fraction of added APP is 15%, the limit oxygen index(LOI)of composites increases to 30.1%. While only adding the PEG with the same mass fraction, the composites can not reach the flame retardant effect. Compared with the pure PLA, the PLA/PEG/APP composites have higher char yield. After adding PEG, the elongation at break obviously increases. While the addition of LCP increases the tensile strength of composites, but reduces the elongation at the break of composites.