纤维素基湿度控制材料的制备与表征

Synthesis and characterization of cellulose humidity control materials

以甲基纤维素作为接枝共聚的原料合成纤维素基湿度控制材料,并加入CaCl2和异丙基丙烯酰胺改善其吸放湿性能;通过间歇式吸附/脱附进行吸、放湿动力学实验与恒温脱附实验,采用热重分析(TG-DTA)和红外光谱(FTIR)表征改性复合材料的热稳定性及其结构。研究结果表明:该类材料具有吸湿量较大、易再生和稳定性高的特性,CaCl2改性材料在相对湿度为100%的最大湿容量为1.45 g/g,吸湿平衡时间约160 h;而相对湿度为90%达到湿平衡的样品放湿需约60 h,在80℃恒温烘箱中脱附40%仅需10 min。加入异丙基丙烯酰胺后材料的放湿速率明显增大,且所有材料在300℃以下具有较强的热稳定性。

Cellulose humidity control materials were synthesised by methyl cellulose as a graft copolymerization of raw materials,and CaCl2 and NIPAm were added into the materials to improve the moisture absorption and desorption performance,and then kinetic experiments of moisture absorption/release on the humidity-controlling composite materials were carried out with the help of batch adsorption/desorption experiment.The thermal decomposition temperature and structure of humidity-controlling composite material were estimated separately by means of TG-DTA and FTIR,and the effects of the moisture absorption/release of humidity-controlling composite material were discussed.The results show that the product has higher hygroscopic capability,easier regeneration and better heat stability.The time of the product modifies by CaCl2 to reach its humidity-controlling balance is about 160 h,the hygroscopic capacity of the product is 1.45 g/g.At the same time,it’s about 60 h to release humidity from the product at 90%,and it only takes 10 min to desorbed 40% of adsorbed water in the 80 ℃ oven.What’s more,the releasing humidity rate of the product modified by NINPAm increases greatly,and the thermal decomposition temperature of the product is about 300 ℃.