引发剂对纤维素接枝丙烯酰胺反应的影响

分别以硝酸铈铵、过硫酸钾和过硫酸钾/亚硫酸钠为引发剂,以马尾松漂白硫酸盐浆纸浆纤维素为骨架接枝丙烯酰胺,在单体浓度为0.75 mol/L、温度为45℃、反应时间为3 h时,得到硝酸铈铵和过硫酸钾的最佳浓度为3.0 mmol/L和5.0 mmol/L,过硫酸钾/亚硫酸钠在用量为6%时的最佳质量比为1.5,三者相应的接枝率分别为40%、48%和60%。同时比较了不同条件下三种引发剂的接枝效果,结果表明,过硫酸钾/亚硫酸钠的接枝效果最好,但均聚物含量高;硝酸铈铵作为引发剂虽然接枝效果不及前两者,但均聚物含量很低。

Effect of Initiators on Graft Copolymerization of Acrylamide onto Cellulose

The study was conducted regarding the effect of initiators on the graft copolymerization of acrylamide onto masson pine bleached sulfate pulp cellulose,i.e.,ammonium cerium nitrate,potassium persulfate and potassium persulfate/sodium sulfite.It can be concluded that the optimum graft conditions included 0.75 mol/L of the monomer concentration,45℃ of reaction temperature,3 h of the reaction time.Additionally,the ideal initiation dosage of ammonium cerium nitrate and potassium persulfate was 3.0 and 5.0 mmol/L respectively.For the initiator of potassium persulfate/sodium sulfite,the optimum dosage was 6% and the best proportion of potassium persulfate/sodium sulfite was 1.5.Under the above optimum conditions,the grafting percentages of the above initiators were 40%,48% and 60%.In addition,the homopolymer contents of the above three initiators were 5%～7%,17%～30% and 20%～27%,respectively.The results indicate that the grafting efficiency of potassium persulfate/sodium sulfite prevails over ammonium cerium nitrate and potassium persulfate.For the homopolymer content,the ammonium cerium nitrate is less than the other two kind of initiator.