Polyolefins used in building materials and furniture require the use of flame-retardant (FR) additives to improve their fire safety. Such additives should be safe to humans and the environment, and preferably bio-based. In the present work, the FR performance of unmodified and chemically modified technical lignins was compared to that of the ammonium polyphosphate/pentaerythritol (APP/PER) intumescent system in a polypropylene (PP) matrix. Micro-scale combustion calorimetry (MCC) was used to study the peak heat release rate (PHR), temperature at PHR (T PHR ), total heat release (THR) and char yield upon thermal decomposition of milligram-scale specimens. The PP/lignin composites showed up to 41% lower PHR and up to 36% lower THR compared to pure PP as well as large char residues. Based on the same parameters, especially the PP/lignin composites made with modified lignins outperformed the reference PP/APP/PER system and the PP/APP/lignin composites where unmodified lignin was used with APP. The most promising PP/lignin composites were prepared with partially demethylated/demethoxylated and depolymerised kraft lignin (‘CatLignin’), modified by the Mannich reaction to a nitrogen content of 13.5%.

中文翻译：

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改性和未改性的工业木质素作为聚丙烯的阻燃剂

用于建筑材料和家具的聚烯烃需要使用阻燃 (FR) 添加剂来提高其防火安全性。这种添加剂应该对人类和环境安全，最好是生物基的。在目前的工作中，未改性和化学改性的工业木质素的阻燃性能与聚丙烯 (PP) 基质中的多磷酸铵/季戊四醇 (APP/PER) 膨胀系统的阻燃性能进行了比较。微型燃烧量热法 (MCC) 用于研究毫克级样品热分解时的峰值放热率 (PHR)、PHR 温度 (T PHR )、总放热 (THR) 和炭产率。与纯PP以及大量的残炭相比，PP /木质素复合材料的PHR降低了41％，THR降低了36％。基于相同的参数，特别是使用改性木质素制成的 PP/木质素复合材料优于参考 PP/APP/PER 系统和未改性木质素与 APP 一起使用的 PP/APP/木质素复合材料。最有前途的 PP/木质素复合材料是用部分去甲基化/去甲氧基化和解聚的硫酸盐木质素 ('CatLignin') 制备的，通过曼尼希反应将氮含量改性为 13.5%。