乙二醛改性支链状阳离子聚丙烯酰胺的合成及其对纸张增强性能的研究

以N-羟甲基双丙烯酰胺(NMA)为交联性单体、2-巯基乙醇为链转移剂,以过硫酸铵和亚硫酸氢钠(mAPS∶mNaHSO3=1∶2)组成氧化还原引发体系引发丙烯酰胺(AM)、阳离子单体甲基丙烯酰氧乙基三甲基氯化铵(DMC),进行水溶液自由基共聚合反应,制备了支链状阳离子聚丙烯酰胺(CPAM)。然后用乙二醛对合成的CPAM进行改性,制备了乙二醛改性的阳离子聚丙烯酰胺树脂(GPAM)。结果表明:当丙烯酰胺用量为55%、NMA用量为8%、2-巯基乙醇用量为1.0%、DMC用量为5.5%、引发剂用量为0.5%(wt)、乙二醛用量为30%(wt)、改性温度为60℃、改性时间为140min时,产物的增强效果较好。当用量为0.3%时,纸张的干抗张指数提高了24.6%,湿抗张指数提高了381%。并用红外光谱(FT-IR)和核磁共振氢谱(1H-NMR)对产物的结构进行了表征。

Synthesis of glyoxal polyacrylamide and modified cross-linked its paper strengthening performance

The cross-linked cationic polyacrylamide （CPAM） was synthesized by using N-methylolacrylamide （NMA） as cross-linking monomer, 2-mercaptoethanol as chain transfer agent, and the ammonium persulfate and sodium hydrogen sulfite together as the redox initiator to initiate acrylamide （AM）, 2-methacryloxyethyl trimethyl ammonium chloride （DMC）. Then glyoxalated polyacrylamide （GPAM） resins were prepared by the graft reaction between glyoxal and CPAM. GPAM demonstrated excellent properties and had a good strengthening ability under the following polymerization conditions： AM dosage 55%（wt）, NMA dosage 8.0%（wt）, 2-mercaptoethanol dosage 1.0%（wt）, DMC dosage 5.5%（wt）, the charge of the initiator （ammonium persulfate ： sodium bisulfite=l ： 2） 0.5%（wt）, the dosage of glyoxal 30%（wt）, reacting temperature 60~C, and reacting time 140 min. The products were characterized by FT-IR and 1H-NMR. When the dosage was 0.3%, the dry tensile index of the hand sheet was increased by 24.6%, wet tensile index of the hand sheet was increased by 381%.