A Novel Durable Flame Retardant with Phosphonate Groups and Reactive Ammonium Phosphorus Acid Groups for Cotton Fabrics

ABSTRACT

A novel flame retardant, tetraethylene pentamine heptamethylene tetraphosphonate dimethyl ester ammonium triphosphorus acid (TPHTDEAT), was synthesized and characterized by NMR. TPHTDEAT-treated cotton fabrics showed excellent flame retardancy tested by the limiting oxygen index (LOI) of 43.3% of cotton fabrics treated with 40 mass% TPHTDEAT and excellent durability tested by LOI of 29.6% of cotton fabrics after 50 laundering cycles according to AATCC 61–2013 2A standard. Most phosphorus existed as phosphonates, which did not combine with metal ions to reduce the flame retardancy during the washing process. P and N atoms were tested by X-ray photoelectron spectroscopy on the treated cotton fibers. The SEM and XRD results implied that flame retardants entered the cotton fiber interiors. The FTIR and durability results suggested that TPHTDEAT was grafted with –OH of cellulose molecules of cotton fibers. The TG analysis suggested that TPHTDEAT promoted char formation during heating process. The cone calorimetry results indicated that the heat release rate and total heat release of TPHTDEAT-treated cotton were much lower than those of untreated cotton. These results indicated that excellent flame retardancy of treated cotton and the durability of treated cotton were increased by introducing phosphonate groups into flame retardant molecules.

摘要

合成了一种新型阻燃剂四乙烯五胺七甲基四膦酸二甲酯三磷酸铵(TPHTDEAT),并用NMR对其进行了表征. 根据AATCC 61-2013 2A标准,经40质量%TPHTDEAT处理的棉织物的极限氧指数(LOI)为43.3%,经TPHTDEAT处理的棉织物表现出优异的阻燃性,经50次洗涤循环后,经LOI测试的棉织物的耐久性为29.6%. 大多数磷以膦酸盐的形式存在,在洗涤过程中不与金属离子结合以降低阻燃性. 用X射线光电子能谱对处理后的棉纤维上的P和N原子进行了测试. SEM和XRD结果表明阻燃剂进入棉纤维内部. FTIR和耐久性结果表明,TPHTDEAT接枝了棉纤维纤维素分子的–OH. TG分析表明,TPHTDEAT在加热过程中促进了焦炭的形成. 锥形量热分析结果表明,TPHTDEAT处理的棉花的热释放速率和总热释放量远低于未处理的棉花. 这些结果表明,处理后的棉具有优异的阻燃性能,此外,在阻燃剂分子中引入膦酸基团可以提高处理后棉的耐久性.

KEYWORDS:

• Flame retardant
• durability
• phosphonate
• cotton fabric
• thermal stability
• cone calorimetry

关键词:

• 阻燃剂
• 耐久性
• 膦酸盐
• 棉织物
• 热稳定性
• 锥形量热仪

Disclosure statement

No potential conflict of interest was reported by the author(s).

Highlights

• TPHTDEAT contains several ammonium phosphorus acid groups and phosphonate groups.

• TPHTDEAT-cotton achieved excellent flame retardancy and outstanding washability.

• The tensile strength of TPHTDEAT-cotton remains good.

• TPHTDEAT-cotton conforms the eco-friendly requirement.

Additional information

Funding

This work was supported by the “Natural Funds for Chongqing” (cstc2019jcyj-msxmX0412) and the “National Natural Science Foundation of China” (Grant No. 21905233).