Sykam Kesavarao, Meka Kiran Kumar Reddy, Donempudi Shailaja
Polymers & Functional Materials Division, Indian Institute of Chemical Technology, Uppal Road, Tarnaka, Hyderabad 500007, Telangana, India.
Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh 201002, India.
ACS Omega. 2019 Jan 14;4(1):1086-1094. doi: 10.1021/acsomega.8b02968. eCollection 2019 Jan 31.
Synthesis of a novel phosphorus and triazole-functionalized flame-retardant (FR) monomer (PTFM) using azide-alkyne "click" reaction between triprop-2-ynyl phosphate and 2-azidoethanol that can impart intumescent FR property to polyurethane foams (PUFs) has been reported. Polyurethane triazole foams (PUTFs) were prepared using the as-synthesized PTFM and a hydroxylated castor polyol with a hydroxyl value of ∼310 mg KOH/g for application as reactive FR rigid foams. PTFM and the castor polyol were characterized for structural elucidation using Fourier transform infrared and H, C, and P NMR. PUTFs with a varying loading content of PTFM were subjected to the lab-scale flame test, cone calorimetry test, Underwriters Laboratory 94 Vertical burning test (UL 94V), and limiting oxygen index (LOI) test. A significant increase in the char yields, reduction in heat release rates, V-1 rating, and 27% of LOI were observed for PUTFs compared to PUFs and proportional to the percentage loading of PTFM. The cumulative effect of nitrogen and phosphorus in PUTFs on their intumescent behavior was evident from the thermogravimetric analysis and scanning electron microscopy micrographs, which were further supplemented by X-ray photoelectron spectroscopy studies, indicating expulsion of N and overall improvement in compression strength as well. Such environment-friendly reactive FRs can be good replacements to the halogenated ones.
据报道，通过磷酸三丙-2-炔酯与2-叠氮乙醇之间的叠氮-炔烃“点击”反应合成了一种新型的磷和三唑官能化阻燃（FR）单体（PTFM），该单体可赋予聚氨酯泡沫（PUF）膨胀型阻燃性能。使用合成的PTFM和羟值约为310 mg KOH/g的羟基化蓖麻油多元醇制备聚氨酯三唑泡沫（PUTF），用作反应型FR硬质泡沫。使用傅里叶变换红外光谱以及氢、碳和磷核磁共振对PTFM和蓖麻油多元醇进行结构解析表征。对不同PTFM负载量的PUTF进行实验室规模的燃烧试验、锥形量热试验、美国保险商试验所94垂直燃烧试验（UL 94V）和极限氧指数（LOI）试验。与PUF相比，观察到PUTF的残炭产率显著提高、热释放速率降低、达到V-1等级，且LOI提高了27%，并且与PTFM的负载百分比成正比。热重分析和扫描电子显微镜照片表明PUTF中氮和磷对其膨胀行为的累积效应很明显，X射线光电子能谱研究进一步证实了这一点，同时还表明氮的排出以及压缩强度的整体提高。这种环境友好型反应型FR可以很好地替代卤化FR。
