Because of good thermal stability, nonflammability and rich structural designability, ionic liquids (ILs) have been used as flame retardants for poly(lactic acid) (PLA). However, as a small molecule, IL has the disadvantages of poor thermal stability and water resistance, and so on. In this paper, an imidazole‐type poly(ionic liquid) (PIL) containing a phosphate anion was synthesized using 1‐vinylimidazole, triethyl phosphate, and 1,2‐divinylbenzene and marked as PDVE[DEP]. The PDVE[DEP] was used to improve the flame retardancy of PLA. The flame retardancy and thermal degradation behaviors of PLA/PDVE[DEP] composites were investigated by the limited oxygen index (LOI), UL‐94 vertical burning, cone calorimetry, and thermal gravity analysis, and so on. The results showed that only 1.0 wt% PDVE[DEP] allows PLA to achieve the UL‐94 V0 rating and obtain LOI value 25.6 vol%. The PDVE[DEP] improve the flame retardancy of PLA by melting‐away mode. In addition, it catalyzes the transesterification of PLA and changes the degradation products.

中文翻译：

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使用磷酸咪唑聚离子液体的高效阻燃聚乳酸

由于良好的热稳定性，不燃性和丰富的结构设计性，离子液体（ILs）已用作聚乳酸（PLA）的阻燃剂。然而，IL作为小分子，具有热稳定性和耐水性差的缺点。在本文中，使用1-乙烯基咪唑，磷酸三乙酯和1,2-二乙烯基苯合成了含磷酸根阴离子的咪唑型聚离子液体（PIL），并标记为PDVE [DEP]。PDVE [DEP]用于提高PLA的阻燃性。通过有限氧指数（LOI），UL-94垂直燃烧，锥形量热法和热重分析等研究了PLA / PDVE [DEP]复合材料的阻燃性和热降解行为。结果显示只有1。0 wt％PDVE [DEP]使PLA达到UL-94 V0等级并获得25.6 vol％的LOI值。PDVE [DEP]通过熔化模式提高了PLA的阻燃性。另外，它催化PLA的酯交换反应并改变降解产物。