A flame-retardant jute/PP composite with excellent flame retarding and mechanical properties was prepared by the surface powder spraying process. The flame-retardant layer used the green and pollution-free β-cyclodextrin as a char agent. To improve the char forming ability of β-cyclodextrin, ammonium polyphosphate (APP) and melamine (MEL) were also used as acid source and a blowing agent, respectively. The results indicated that the char forming ability of β-CD could be improved by the reaction between β-CD and APP. The composite with 20% flame retardants containing β-CD, APP and MEL (1:2:1) showed the better flame-retardant properties. The LOI value of the composite increased to 27.8%, which reached the second fire resistance according to Japan's JISD 1201-77 standard, and the self-extinguishing time reached to 37 s. Compared with pure jute/PP, the PHRR value and Av-EHC value of the composites were reduced by 50% and 21%, respectively. The carbon residual at 700 °C was increased by 10.9%. The tensile strength and bending strength were increased by 5% and 19%. These results revealed that the flame retardancy, thermal stabilities and mechanical properties of composites containing β-CD/APP/MEL system were significantly improved by the surface powder spraying method.

中文翻译：

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以β-环糊精为炭化剂的膨胀型阻燃层及其在黄麻/聚丙烯复合材料中的阻燃性

采用表面喷粉工艺制备了具有优异阻燃性能和力学性能的阻燃黄麻/PP复合材料。阻燃层采用绿色无污染的β-环糊精作为焦化剂。为了提高β-环糊精的成炭能力，多磷酸铵（APP）和三聚氰胺（MEL）也分别用作酸源和发泡剂。结果表明，β-CD与APP的反应可以提高β-CD的成炭能力。含有 20% 阻燃剂的 β-CD、APP 和 MEL (1:2:1) 的复合材料表现出更好的阻燃性能。复合材料的LOI值提高到27.8%，达到日本JISD 1201-77标准的二级耐火性，自熄时间达到37s。与纯黄麻/PP相比，复合材料的PHRR值和Av-EHC值分别降低了50%和21%。700 °C 时的碳残留量增加了 10.9%。拉伸强度和弯曲强度分别提高了5%和19%。这些结果表明，表面粉末喷涂方法显着提高了含有β-CD/APP/MEL体系的复合材料的阻燃性、热稳定性和力学性能。