This article investigates reacting potassium salts of phosphorous‐containing acids in the presence of urea with cotton cellulose under thermosol conditions (pH 5, 185 °C) to esterify the cellulose and produce a flame‐retardant effect. Attenuated total reflectance‐Fourier‐transform infrared (ATR‐FTIR) spectroscopy confirmed chemical modification of the cotton cellulose, where only the phosphite salt formed a covalently bonded cellulose ester (confirmed by flammability tests). Urea plays a vital role; decomposing to ammonia and isocyanic acid (the reactive intermediate) and it is the isocyanic acid/phosphite anion addition compound that reacts with cellulose hydroxyl groups to form the required ester. ATR‐FTIR analysis showed that phosphate and hypophosphite salts did not react with cellulose and thus gave no flame‐resist effect. Whilst the esterification of cellulose introduces phosphorous onto the cellulose, in order to meet more severe work‐wear laundry standards it was necessary to further incorporate a nitrogen species by addition of a cationic polymer. To develop a one shot “all‐in” process the possibility of simultaneously bonding nitrogen through carbodimide chemistry is researched, with initial promising trials demonstrated. Many after‐treatments of dyed fabrics can cause colour shifts due to interactions with the chromophores. Azo dyes, for example, are particularly susceptible to attack by the formaldehyde produced during the Pyrovatex process or the reducing nature of the Proban process, both resulting in a colour change. An advantage of the novel phosphite/urea flame‐retardant system presented herein, is that the system is less aggressive which allows the possibility of using reactive dyes to produce a bright and wide shade range as the results demonstrate.

中文翻译：

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以环保的方式处理阻燃纤维素织物的新方法

本文研究了在尿素存在下，含磷酸的钾盐与棉纤维素在热溶胶条件下（pH 5，185°C）反应，以酯化纤维素并产生阻燃作用。衰减的全反射傅里叶变换红外（ATR-FTIR）光谱证实了棉纤维素的化学修饰，只有亚磷酸酯盐形成了共价键合的纤维素酯（通过可燃性测试确认）。尿素起着至关重要的作用。分解为氨和异氰酸（反应性中间体），是异氰酸/亚磷酸根阴离子加成化合物与纤维素羟基反应形成所需的酯。ATR-FTIR分析表明磷酸盐和次磷酸盐与纤维素不发生反应，因此没有阻燃作用。纤维素的酯化将磷引入纤维素时，为了满足更严格的工作服洗衣标准，有必要通过添加阳离子聚合物进一步掺入氮。为了开发“一次性”全过程，研究了通过碳二亚胺化学方法同时键合氮的可能性，并进行了初步有希望的试验。由于与生色团的相互作用，许多对染色织物的后处理都可能导致颜色偏移。例如，偶氮染料特别容易受到Pyrovatex工艺过程中产生的甲醛或Proban工艺的还原性质的侵蚀，两者都会导致颜色变化。本文介绍的新型亚磷酸酯/脲阻燃系统的优势，