Terminal group effects of phosphazene-triazine bi-group flame retardant additives in flame retardant polylactic acid composites
Terminal group effects of phosphazene-triazine bi-group flame retardant additives in flame retardant polylactic acid composites
复制标题
阻燃聚乳酸复合材料中磷腈-三嗪双基团阻燃添加剂的端基效应
DOI：
10.1016/j.polymdegradstab.2017.04.024
复制
发表时间：
2017-06-01
影响因子：
5.9
通讯作者：
Xin, Fei
中科院分区：
文献类型：
--
作者：
Chen, Yajun;Wang, Wei;Xin, Fei
以六氯环三磷腈（HCCP）、三聚氯氰和胺类化合物（乙二胺、苯胺、对苯二胺）为原料，合成了3种不同端基的磷腈-三嗪双基团阻燃剂（Al、A2、A3）。然后分别与聚磷酸铵（APP）复合制备阻燃聚乳酸（PIA）。采用傅里叶变换红外光谱（FTIR）、H-1和C-13固态核磁共振谱仪以及热重分析（TGA）对这三种阻燃添加剂的分子结构和热稳定性进行了表征。通过极限氧指数（LOI）、垂直燃烧、锥形量热仪（CCT）、扫描电镜（SEM）、热重-红外联用仪（TGA-FTIR）等测试手段研究了阻燃PLA复合材料的阻燃性能和阻燃机理。结果表明，端氨基磷腈-三嗪双基团阻燃剂（A1或A3）与APP复配后对PIA树脂的阻燃性能优于不含端氨基的A2阻燃剂。PLA/Al/APP体系的阻燃性能最好，其LOI值最高，为34.3%，且达到UL-94 V-0级，无滴落现象。同时，与其他阻燃PLA复合材料相比，它不仅获得了最低的PLC-HRR、THR和TSR，而且保留了最多的残炭。这种显著的阻燃性能的提高归因于气相中PO 2自由基的猝灭效应和惰性气体的稀释效应，以及冷凝相中的阻挡和保护效应和成炭效应。PLA/A2/APP体系的阻燃性能较差的原因是由于体系的阻隔保护作用和凝聚相的成炭作用不足。这表明阻燃剂端基的调整不仅影响其阻燃作用方式，而且有助于探索更有效的阻燃结构或体系。(C)2017爱思唯尔有限公司版权所有
Three phosphazene-triazine bi-group flame retardant additives (Al, A2, A3) with different terminal groups were synthesized from hexachlorocyclotriphosphazene (HCCP), cyanuric chloride and amine compounds (ethylenediamine, aniline, or p-phenylenediamine). Then they were applied with ammonium polyphosphate (APP) to prepare flame-retardant polylactic acid (PIA), separately. The molecule structures and thermal stabilities of these three flame retardant additives were characterized by Fourier transformed infrared spectrometry (FTIR), H-1 and C-13 Solid-State NMR spectrometer and thermogravimetric analysis (TGA). The flame-retardant properties and mechanism of the flame-retardant PLA composites were investigated by the limited oxygen index (LOI) test, vertical burning test, cone calorimeter test (CCT), scanning electron microscopy (SEM), and thermogravi-metric analyzer coupled to a Fourier-transform infrared spectrometer (TGA-FTIR). Results showed that the combination of phosphazene-triazine bi-group flame retardant additive with amino-terminated groups (Al or A3) and APP brought better flame retardant properties to PIA resin than that of A2 without amino -terminated groups. PLA/Al/APP system got the best flame retardant properties, which exhibited the highest LOI value of 34.3% and preferably achieved UL-94 V-0 rating without dripping. Meanwhile, it not only obtained the lowest plc-HRR, THR, and TSR, but also reserved the largest amount of residual char, compared with other flame-retardant PLA composites. Such a significant improvement in flame retardancy was attributed to the PO2 radical quenching effect and inert gas dilution effect in gas phase, as well as barrier and protective effect and charring effect in condense phase. Besides, the poor performance on flame retardancy of PLA/A2/APP system was due to the lack of barrier and protective effect and charring effect in condense phase. All these revealed that the adjustment on terminal groups of flame-retardant additives not only affects their flame-retardant work mode, but also helps to explore the more efficient flame-retardant structures or systems. (C) 2017 Elsevier Ltd. All rights reserved.