阳离子瓜尔胶的制备及其助留助滤性能

Preparation and its retention and drainage aid performance of cationic guar gum

以瓜尔胶原粉为原料,3-氯-2-羟丙基三甲基氯化铵(CTA)为阳离子醚化剂,分别在4种离子液体中制备了4种阳离子瓜尔胶(CGG)。经测定,在离子液体[AMIM]Ac中合成的阳离子瓜尔胶具有最高的氮质量分数。利用正交实验和单因素实验考察了醚化剂用量、反应温度、反应时间、碱化时间、碱用量对产物氮质量分数及黏度的影响,确定了优化合成条件。经测定,产物的氮质量分数为1.95%,黏度为583 mPa·s。对比发现,在[AMIM]Ac中合成的阳离子瓜尔胶较在乙醇和异丙醇中合成的阳离子瓜尔胶具有更高的氮质量分数和黏度,说明离子液体对瓜尔胶的醚化反应起到一定的保护作用。对比不同取代度和在不同溶剂中合成的阳离子瓜尔胶对脱墨废纸浆的细小组分单程留着率(FPR)发现,CGG-5的助留效果最好(CGG-5用量为0.06%,FPR为72.3%)。

Four cationic guar gums(CGG)were prepared in four ionic liquids using guar gum powder as raw material and 3-chloro-2-hydroxy propyltrimethylammonium chloride(CTA)as the cationic etherifying agent.It was determined that CGG synthesized in ionic liquids[AMIM]Ac had the highest nitrogen mass frac⁃tion.The effects of the dosage of etherification agent,reaction temperature,reaction time,alkalization time and the dosage of alkali on the nitrogen mass fraction and viscosity of the product were investigated by or⁃thogonal experiments and single factor experiments to determine the optimum synthesis conditions.The re⁃sults showed that the nitrogen mass fraction of product was 1.95%,and the viscosity was 583 mPa·s.The comparison showed that CGG synthesized in ionic liquids had higher nitrogen mass fraction and viscosity than that synthesized in ethanol and isopropanol,indicating that ionic liquids had a certain protective effect in the etherification of guar gum.Finally,comparing the first pass retention rate(FPR)of fine constituents of deinked pulp by cationic guar gum with different degree of substitution and synthesized in different solvents,the reten⁃tion effect of CGG-5 was the best(the dosage of CGG-5 was 0.06%,FPR was 72.3%).