Zhang Xiaolei, Yang Yubin, Li Meitong, Wu Jingxuan, Zhu Zhe, Bi Chengliang, Xie Yuhong, Wang Taoyun, Sun Yongyan, Yin Jing, Xie Zhanghua, Liu Fude, Wang Junsheng, Yang Jinjun
Tianjin Key Laboratory of Hazardous Waste Safety Disposal and Recycling Technology, School of Environmental Science and Safety Engineering, Tianjin University of Technology, 391 Binshui Xidao, Xiqing District, Tianjin 300384, China.
School of Chemistry and Life Sciences, Suzhou University of Science and Technology, Suzhou, China.
Int J Biol Macromol. 2023 Apr 15;234:123666. doi: 10.1016/j.ijbiomac.2023.123666. Epub 2023 Feb 15.
In this work, the β-cyclodextrin (β-CD) was modified by a phosphazene compound to prepare a novel amorphous derivate (β-CDCP), which was combined with the ammonium polyphosphate (APP) as a synergistic flame retardant (FR) of the bio-based poly(L-lactic acid) (PLA). The effects of the APP/β-CDCP on the thermal stability, combustion behavior, pyrolysis process, fire resistance performance and crystallizability of the PLA were investigated comprehensively and in depth by thermogravimetric (TG) analysis, limited oxygen index (LOI) analysis, UL-94 test, cone calorimetry measurement, TG-infrared (TG-IR), scanning electron microscopy-energy dispersive spectrometer, Raman spectroscopy, pyrolysis-gas chromatography/mass spectrometry and differential scanning calorimetry. The PLA/5%APP/10%β-CDCP showed a highest LOI of 33.2 %, passed V-0 rating and exhibited self-extinguish phenomenon in the UL-94 test. Also, it presented a lowest peak of heat release rate, total heat release, peak of smoke production rate and total smoke release, and a highest char yield treated by cone calorimetry analysis. In addition, the 5%APP/10%β-CDCP shortened significantly crystallization time and enhanced crystallization rate of the PLA. Gas phase and intumescent condensed phase fire proofing mechanisms are proposed to elucidate enhanced fire resistance in this system in detail.
在本工作中，用磷腈化合物对β-环糊精（β-CD）进行改性，制备了一种新型无定形衍生物（β-CDCP），并将其与聚磷酸铵（APP）复合作为生物基聚（L-乳酸）（PLA）的协同阻燃剂。通过热重（TG）分析、极限氧指数（LOI）分析、UL-94测试、锥形量热法测量、TG-红外（TG-IR）、扫描电子显微镜-能谱仪、拉曼光谱、热解-气相色谱/质谱和差示扫描量热法，全面深入地研究了APP/β-CDCP对PLA的热稳定性、燃烧行为、热解过程、耐火性能和结晶性的影响。PLA/5%APP/10%β-CDCP在UL-94测试中显示出最高极限氧指数为33.2%，通过了V-0等级，并表现出自熄现象。此外，通过锥形量热法分析，它还呈现出最低的热释放速率峰值、总热释放量、产烟速率峰值和总烟释放量，以及最高的残炭率。另外，5%APP/10%β-CDCP显著缩短了PLA的结晶时间并提高了其结晶速率。提出了气相和膨胀凝聚相防火机理，以详细阐明该体系中增强的耐火性。
