纤维素与丙烯酸在氯化锌水溶液中的均相接枝

Homogeneous Graft of Acrylic Acid onto Cellulose in Zinc Chloride Aqueous Solution

以质量分数为65%的氯化锌水溶液为反应介质、过硫酸钾为引发剂,研究了微晶纤维素(MCC)与丙烯酸(AA)的均相接枝共聚反应,考察了引发剂用量、引发时间、接枝共聚时间、单体用量等因素对接枝率的影响,并用FT-IR、XRD和TGA分析了接枝前后微晶纤维素的特性.结果表明:当引发剂与MCC的质量比为1∶2、单体与MCC的质量比为5∶1、引发时间为10 min、接枝共聚时间为8 h、共聚温度为60℃时,接枝率达20.3%;随接枝时间的延长,接枝产物粒径呈减小趋势,电位呈增加趋势;接枝后的产物在1729cm-1处有CO的吸收峰,说明接枝上了丙烯酸单体;接枝后MCC的结晶度及热分解温度均降低.

The homogeneous graft copolymerization of acrylic acid（AA） and microcrystalline cellulose（MCC） was carried out,with potassium persulfate as the initiator and with 65% zinc chloride aqueous solution as the reaction medium.Then,the effects of initiator dosage,initiation time,grafting time and monomer dosage on the grafting ratio were discussed,and the characteristics of the MCC before and after the grafting were analyzed by means of FT-IR,XRD and TGA.The results show that,at a initiator-to-MCC mass ratio of 1 ∶ 2,a monomer-to-MCC mass ratio of 5 ∶ 1 and a initiation time of 10 min,the copolymerization at 60 ℃ for 8 h may result in a grafting ratio of 20.3%,that the size of the grafted copolymer shows a decreasing trend while the potential shows an increasing trend with the prolonging of grafting time,that acrylic acid successfully grafts onto MCC because there exists a CO absorption peak at 1 729 cm^-1 of the grafted copolymer,and that both the crystallinity and the thermal decomposition temperature of MCC decrease after the grafting.