以离子液体为反应介质,丙烯酰胺为单体,在不加任何引发剂的情况下,用微波辐射代替常规的加热方式,在均相条件下快速合成了纤维素与丙烯酰胺的接枝共聚物。研究了影响接枝效果的各种因素(单体及交联剂的用量,微波强度以及反应时间等),并利用红外光谱(FT-IR)、扫描电镜(SEM)、热重分析(TGA)等手段对其结构及表面形态进行表征。结果表明,通过微波辐射,纤维素在离子液体中1 min便可完成接枝反应,与常规加热时间(0.5-5 h)相比,该方法大大缩短了反应时间。此外,还探讨了微波下纤维素接枝共聚的自由基反应机理。
Acrylamide was grafted onto cellulose in homogeneous phase in the absence of any radical initiator under microwave(MW) irradiation using 1-butyl-3-methylinidazolium chloride ionic liquid as the reaction medium.The use of microwave resulted in a dramatic reduction of reaction time: 1 min irradiation was sufficient,compared with 0.5 to 5 hours as conventional heating was used.The effects of reaction parameters,such as monomer concentration,crosslilnker dosage,MW power and exposure time were investigated.The structure of the grafted copolymer was confirmed by FT-IR spectrum,TGA and SEM.A probable free radical mechanism for grafting under microwaves was also proposed.