瓜尔胶醚化改性及其在废纸湿部体系中的应用

The ether modification of guar gum and its application in deinked pulp wet-end system

探讨了有机溶剂法制备阳离子瓜尔胶的影响因素,以取代度、Zeta电位、反应效率等指标对其进行表征,优化出阳离子瓜尔胶的最佳合成工艺:碱用量2%,乙醇体积分数70%,液比1∶3,反应时间2h,反应温度60℃,醚化剂与瓜尔胶摩尔比1.0。在此条件下可获得取代度0.39的阳离子瓜尔胶。对其结构进行红外谱图分析,证实了醚化反应的发生。将合成后的阳离子瓜尔胶应用于废纸浆湿部体系,结果表明,阳离子瓜尔胶取代度越高,对废纸浆的助留效果越好。超声波助溶能有效改善阳离子瓜尔胶的使用性能。当取代度0.392的阳离子瓜尔胶用量为0.5%时,体系Zeta电位为-6.8mV,固形物留着率和填料留着率达到最大,分别为95.7%、87.3%,较空白样分别提高了14.1%和68.5%,打浆度下降18°SR。

The technological parameters affecting synthesis of cationic guar gum through the method of organic solvent were reported.Based on DS,zeta potential,reaction efficiency of modified products,the optimum condition for synthesis of cationic guar gum was listed as 2% of alkali dosage,70% of ethanol volume fraction,1∶3of liquid ratio,2hof reaction time,60 ℃ of reaction temperature,molar ratio 1.0of etherification agent and guar gum.Under this condition,the substitution degree of cationic guar gum was up to 0.39.FT-IR spectrum wes analyzed in order to confirm the molecular structure of cationic guar gum.The results showed that the cationic guar gum with a higher DSvalue exhibited a higher retention for waste paper.The ultrasound solubilization could effectively improve the performance of cationic guar gum.When the dosage of cationic guar gum with a DSvalue of 0.392 was 0.5%,the zeta potential of deinked pulp system was-6.8mV.And the solids retention and filler retention was high up to 95.7%and 87.3%,respectively.Compared with controlled,they were increased by 14.1%and 68.5%,respectively.Beating degree of pulp system was highly decreased by18°SR.