State Key Laboratory of Fire Science , University of Science and Technology of China , 96 Jinzhai Road , Hefei , Anhui 230026 , PR China.
Department of Physical Science , University of California , Irvine , California 92697 , United States.
ACS Appl Mater Interfaces. 2018 Nov 21;10(46):40168-40179. doi: 10.1021/acsami.8b15355. Epub 2018 Nov 6.
It has been a big challenge to prepare the unsaturated polyester resin (UPR) composites with good fire safety, interfacial quality, and impact strength in an environmentally friendly way. In this study, to improve interfacial performance of fabric-reinforced UPR composites, nontoxic two-dimensional hexagonal boron nitride (h-BN) nanosheets were assembled on the surface of ramie fabrics, where sodium alginate acts as a green dispersant to disperse h-BN sheets during the process. Then, the biobased phosphorus-containing toughening agent (PCTA) was synthesized to simultaneously improve the impact strength and fire safety of the composite. With application of h-BN nanosheets-assembled fabric (AF) and 20 wt % of PCTA, the AF/UPR@PCTA composite presented the maximum 41.2% decrease in the value of peak heat release rate and a maximum 17.8% decrease in the value of total heat release, which also reached V-0 rating in the vertical burning test. Meanwhile, the AF/UPR@PCTA composite showed an obvious increase in limiting oxygen index, from 24.0 to 29.5% compared with RF/UPR. The flame retardant mechanism was investigated from gas phase and condensed phase. Furthermore, compared to neat RF/UPR composite, the AF/UPR@PCTA composite showed a significant 68.8% improvement in impact strength, implying an extreme toughening effect of PCTA on UPR composites. The research provides a viable green method for the development of environmentally friendly UPR composites in the future.
用环保的方法制备具有良好防火性能、界面质量和抗冲击强度的不饱和聚酯树脂（UPR）复合材料一直是一个巨大的挑战。在这项研究中，为了提高纤维增强 UPR 复合材料的界面性能，无毒二维六方氮化硼（h-BN）纳米片被组装在苎麻织物的表面上，其中海藻酸钠作为一种绿色分散剂，在过程中分散 h-BN 片。然后，合成了生物基含磷增韧剂（PCTA），以同时提高复合材料的抗冲击强度和防火安全性。应用组装有 h-BN 纳米片的织物（AF）和 20wt%的 PCTA，AF/UPR@PCTA 复合材料的峰值放热率降低了 41.2%，总放热量降低了 17.8%，在垂直燃烧试验中也达到了 V-0 等级。同时，AF/UPR@PCTA 复合材料的极限氧指数明显提高，与 RF/UPR 相比，从 24.0%提高到 29.5%。从气相和凝聚相研究了阻燃机理。此外，与纯 RF/UPR 复合材料相比，AF/UPR@PCTA 复合材料的抗冲击强度显著提高了 68.8%，表明 PCTA 对 UPR 复合材料具有极强的增韧效果。该研究为未来环保型 UPR 复合材料的开发提供了一种可行的绿色方法。
