A fully biobased waterborne flame-retarded epoxy system was prepared using sorbitol polyglycidyl ether epoxy resin (SPE) and phytic acid (PA) as a reactive flame retardant (FR). The flame-retardant efficiency was evaluated by comparing the reference SPE-PA system with solventborne and waterborne SPE systems. Additional enhancement of intumescence and reduction of flammability was achieved by incorporating ammonium polyphosphate (APP) and melamine (MEL) into the SPE–PA system. PA, serving as a curing agent, contributed approximately 1% phosphorous content, resulting in an increased limiting oxygen index (LOI). UL-94 flammability tests demonstrated improved FR properties with PA, and the addition of 2% phosphorous from APP to SPE-PA achieved a self-extinguishing V0 UL-94 rating. Thermogravimetric analysis (TGA) revealed enhanced thermal stability and higher char yield with PA compared with other curing agents. Mass loss calorimetry (MLC) confirmed the superior charring effect of PA compared with other curing agents. The thermal insulation properties of the residual char were assessed by measuring the temperature on the back surface (Tb) of coated steel plates exposed to a 25 kW/m² heat flux for 1 h. The PA sample containing 3%P of APP exhibited a Tb decrease of 130°C compared with the solventborne reference sample. Scanning electron microscopy analysis of the char morphology supported these findings, indicating the effectiveness of the intumescent FR system. Infrared spectra of the char residues and pyrolysis gaseous products were obtained to gain insights into the flame-retardant mechanism of the different systems.

中文翻译：

---

利用植酸作为反应型阻燃剂制备全水性生物基环氧体系

以山梨醇聚缩水甘油醚环氧树脂（SPE）和植酸（PA）作为反应型阻燃剂（FR）制备了全生物基水性阻燃环氧体系。通过将参考 SPE-PA 系统与溶剂型和水性 SPE 系统进行比较来评估阻燃效率。通过将聚磷酸铵 (APP) 和三聚氰胺 (MEL) 纳入 SPE-PA 系统，进一步增强了膨胀性并降低了可燃性。 PA 作为固化剂，贡献了约 1% 的磷含量，导致极限氧指数 (LOI) 增加。 UL-94 可燃性测试表明，PA 改善了阻燃性能，并且在 SPE-PA 中添加 APP 中的 2% 磷，实现了自熄性 V0 UL-94 等级。热重分析 (TGA) 表明，与其他固化剂相比，PA 具有更高的热稳定性和更高的炭产率。失重量热法 (MLC) 证实了 PA 与其他固化剂相比具有优异的炭化效果。通过测量暴露于25kW/m ²热通量1小时的涂层钢板的背面温度(Tb)来评估残余炭的隔热性能。与溶剂型参考样品相比，含有 3%P APP 的 PA 样品的 Tb 降低了 130°C。对炭形态的扫描电子显微镜分析支持了这些发现，表明膨胀阻燃系统的有效性。获得了炭残留物和热解气态产物的红外光谱，以深入了解不同系统的阻燃机理。