金属离子阻燃改性淀粉研究

Investigation on Flame Retardancy of Starch Modified with Metal Ions

为提高淀粉的阻燃性能,以玉米淀粉为原料,无水乙醇为溶剂,用溶媒法制备出了含有不同碱金属离子(Na+、K+、Li+)的改性淀粉。利用红外光谱仪、氧指数测试仪、电感耦合等离子体发射光谱仪、热重分析仪对其结构和性能进行表征和分析。通过红外谱图(FTIR)的分析可以证明改性后的淀粉分子链上成功接枝了金属离子。极限氧指数(LOI)和电感耦合等离子体发射光谱(ICP)的测试结果表明,与改性前淀粉相比,改性后淀粉的极限氧指数得到明显提高,且金属离子含量越高,改性淀粉的极限氧指数也越高。利用热重分析(TGA)对改性淀粉的热性能进行分析,其结果表明钠离子、钾离子、锂离子的存在都能使样品残碳量大大增加,改性淀粉在燃烧过程中的残碳可以构成膨胀炭层,并且金属离子可以催化淀粉在热解时形成稳定的物质减少可燃物的生成。

In order to improve the flame retardancy of starch, modified starch containing different metal ions (Na+、K+、Li+) was prepared in the alcohol phase by using the corn starch as raw material. The structure and properties were characterized by Fourier transform infrared, limiting oxygen index, inductively coupled plasma-emission spectroscopy and thermogravimetric analysis. The FTIR shows that the native starch was successfully reactioned with metal ions;the LOI and ICP results show that the LOI values of the modified starch were higher than the native starch, and the higher the metal ion content, the higher the LOI values of the modified starch;the results from TGA indi-cate that the presence of alkali metal ion greatly increases the residual amount of the sample, and the residue of the modified starch in the combustion process can constitute an expanded carbon layer and catalyze the formation of a stable substance in the thermal cracking of the starch. It can be seen that the introduction of metal ions has a certain improvement on the flame retardancy of the native starch.