Tomiak Florian, Schoeffel Angelina, Rathberger Klaus, Drummer Dietmar
Institute of Polymer Technology, Friedrich-Alexander-University Erlangen-Nuremberg, Am Weichselgarten 9, 91058 Erlangen, Germany.
Bavarian Polymer Institute, Friedrich-Alexander-University Erlangen-Nuremberg, Dr. Mack Strasse 77, 90762 Fuerth, Germany.
Polymers (Basel). 2021 Aug 13;13(16):2712. doi: 10.3390/polym13162712.
Expandable graphite (EG), aluminum (diethyl)polyphosphinate (AlPi) and melamine polyphophate (MPP) was used as flame retardant multi-material additive in a polyamide 6 (PA6) matrix. Flame inhabitation performances were conducted by cone calorimeter, LOI and UL-94 tests, synergisms identified analyzed by TGA-FTIR and TGA-GC/MS and effects found were comprehensively discussed. SEM images were used for char residue characterization. For PA6 containing 20 wt.% EG and 5 wt.% AlPi/MPP (3:2), a well working synergism in limiting oxygen indices could be identified exhibiting the highest oxygen index (OI) measured: 46%. The study shows that the synergism due to the partial substitution of EG by AlPi/MPP can be attributed to two effects: (1) When PA6/AlPi/MPP mixtures decompose predominantly CO evaporates in early decomposition stages. CO evaporations was found to be sensitive to the heating rate applied, whereas specifically high heating rates increased the CO yield measured. (2) Solid decomposition products of AlPi/MPP act as "glue" between expanded graphite and thus increase the mechanical residue stability.
可膨胀石墨（EG）、聚磷酸二乙酯铝（AlPi）和三聚氰胺聚磷酸盐（MPP）被用作聚酰胺6（PA6）基体中的阻燃多材料添加剂。通过锥形量热仪、极限氧指数（LOI）和UL - 94测试来评估阻燃性能，通过热重 - 傅里叶变换红外光谱（TGA - FTIR）和热重 - 气相色谱/质谱联用仪（TGA - GC/MS）来识别和分析协同作用，并对所发现的效果进行全面讨论。扫描电子显微镜（SEM）图像用于表征残炭。对于含有20 wt.% EG和5 wt.% AlPi/MPP（3:2）的PA6，在极限氧指数方面可识别出良好的协同作用，测得的最高氧指数（OI）为46%。研究表明，AlPi/MPP对EG的部分替代所产生的协同作用可归因于两种效应：（1）当PA6/AlPi/MPP混合物分解时，在早期分解阶段主要蒸发的是CO。发现CO的蒸发对所施加的加热速率敏感，而特别高的加热速率会增加测得的CO产量。（2）AlPi/MPP的固体分解产物在膨胀石墨之间起到“胶水”的作用，从而提高了残炭的机械稳定性。
