湿部化学讲义【高级课件】

1、造 纸 湿 部 化 学 戴红旗,化学工程学院造纸与印刷工程系 Department of Paper &Print Science Nanjing Forestry University,湿部化学？,在造纸系统中相互作用的所有组成： 表面/界面 离子 胶体,湿部化学研究的内容,一切你看不见，但你又确实看得到它们在影响着纸的质量及纸机的运行性能。,重要性,Achievement of Paper Properties 纸性 Structural formation 结构成形 Mechanical strength 机械强度 Appearance optical 外观光学 Barrier & Re

2、sistance sizing 抗液体渗透施胶 Permanence stability 形稳性 Enhancement of Runnability 运行性提高 Machine Efficiency 纸机效率 Drainage speed 滤水速度 Foaming 泡沫 Spots, Holes & Deposits 斑点、针眼、沉积,湿部化学,Materials 原材料 Types 类型 Characteristics 特性 Principles Surface Area 表面积 Conductivity 电导率 Electrostatic Charge 电荷密度 Coagulation

3、& Flocculation 凝结和絮聚,纸料的组成?,Water 水 Dissolved Electrolytes 溶解性电介质 Suspended Fibers 纤维 Suspended Fiber Fines 细小纤维 Suspended Filler Particles 填料 Surface-active Molecules (alone or as aggregates, i.e. detergents, dispersants, wood extractives, defoamers) 表面活性剂 Dissolved Polyelectrolytes - i.e. PAM, cat

4、ionic starch wet and dry strength resins 水溶性聚电介质 Aggregated Sizing Molecules 聚结的施胶剂分子,造纸组成的形状和尺寸,纤 维: 直径10-50 um ，长1-7 mm 细小纤维: 直径 1 um，长 76 um 填 料: 0.1-10 um ASA/AKD胶粒: Ca+2 Na+1 聚电解质比简单电解质更有效 polyamine alum,絮聚,Patch Flocculation 补丁絮聚 Bridge Flocculation 桥联絮聚 “Un-Flocculation” 缔合絮聚,Patch Flocculati

5、on补丁絮聚,_ _ _ _ _ _ _ _ _ _,_ _ _ _ _ _ _ _ _ _,Anionic Particle,阴离子颗粒,低分子量、 高阳电荷密度聚合物,+ + + + + + +,_ _ _ _ _ _ _ _ _ _,+ + + + +,+ + + + +,Patch Flocculation补丁絮聚,通常采用低分子量阳电荷聚电解质 对剪切力敏感 剪切后的聚集为软絮聚,Bridging Flocculation桥联絮聚,高分子量 低电荷密度聚合物,吸附开始阶段,絮聚,_ _ _ _ _ _ _ _ _ _ _ _ _,_ _ _ _ _ _ _ _ _ _ _ _ _,+

6、 + + + + + + + + + + + + + + + + + +,+ + + + + + + + + + + + + + + + + + + + + + +,_ _ _ _ _ _ _ _ _ _ _ _,Bridging Flocculation桥联絮聚,Accomplished with high molecularweight polymers 高分子量聚合物 Highly influenced by molecular weight and charge density of polymer 极大地受到聚合物分子量、电荷密度影响 Forms larger flocs 形成大絮聚

7、 Aggregates tend to reform as patch (soft) flocs when sheared 当受剪切时，聚集倾向于重新形成补丁絮聚,Hard Floc Behavior硬絮聚行为,_ _ _ _ _ _ _ _ _ Initial Adsorption,+ + + + + + + + + +,_ _ _ _ _ _ _ _ _ Initial Flocculation (Hard Floc),+ + + + + + + + + +,_ _ _ _ _ _ _ _,SHEAR,+ + + + + + + + + +,_ _ _ _ _ _ _ _ _ Reconf

8、irmation,+ + + + + + + + + +,_ _ _ _ _ _ _ _ _ _ _ Reflocculation (Soft Floc),_ _ _ _ _ _ _ _,The Two Can Be Combined 两者组合,Patching 补丁,Bridging 桥联,+,Dual Polymer System 双组分系统,Dual Polymer System双组分系统,_ _ _ _ _ _ _ + + _ _ _ +,_ _ _ _ _ _ _ + + _ _ _+,_ _ _ _ _ _,Patch,Anionic Polymer,_ _ _ _ _ _ _ _

9、 _,_ _ _ _ _ _ _ + + _ _ _ +,_ _ _ _ + + _ _ _ + + _ _,_ _ _ _ _ _ _ _ _ _,Bridge,Patch plus Anionic polymer,影响聚合物吸附的因素,Polymer Characteristics - charge density, molecular weight, chain length, backbone conformation, flexibility 聚合物特性：电荷密度、分子量、链长、骨架构造、柔韧性 Particle Characteristics - available adsorpt

10、ion sites, surface area, surface charge 粒子特性：可吸附的位置、表面积、表面电荷 Physical Environment - shear and turbulence, furnish consistency, order of addition 物理环境：剪切力、浆浓、添加顺序 Chemical Environment - pH, conductivity, “interfering substances” 化学环境：pH、电导率、干扰物质,聚合物电荷密度,Weak Absorption, Weak Flocculation Good Absorpt

11、ion, Strong Bridge Formation Strong Adsorption, Good Patch Formation,_ _ _ _ _ _ _ _,_ _ _ _ _ _ _ _,_ _ _ _ _ _ _ _,Low,Medium,High,+,+,+,+,+,+,+,+,+,+,+,Particle Charge Density 粒子电荷密度,Weak Absorption, Weak Flocculation 弱吸附、弱絮聚 Good Absorption, Strong Bridge Formation 中等吸附、强的桥联 Strong Adsorption, G

12、ood Patch Formation 强吸附、中等补丁,_ _,_ _ _,_ _ _ _ _ _ _ _,Low低,Medium中,High高,+,+,+,+,+,+,+,+,+,+,+,Interfering Substances 干扰物质,Fresh Water（新鲜水） Calcium and Magnesium hardness（Ca、Mg硬度） Organic Matter（有机物） Residual Chlorine（残余氯化物） Suspended solids（悬浮物） Pulping Residuals（制浆残余物） Sodium salts（钠盐） Rosin soap

13、s（松香皂） Fatty acid soaps（脂肪酸皂） Lignin compounds（木素化合物）,Interfering Substances 干扰物质,Bleaching Residuals 漂白残留 Sodium salts 钠盐 Calcium salts from Calcium hypochlorite（钙盐基） Alkali-soluble cellulose and hemicellulose （碱溶性纤维素、半纤维素） Broke（损纸） Starch（淀粉） Adhesives（胶粘剂） Inks（油墨） Coating Components（涂料）,Interfe

14、ring Substances 干扰物质,Conductivity 电导率 Measurement of dissolved ions 溶解离子的测量 Many “interfering substances” are soluble ionized materials许多干扰物质为水溶性的、离子化的物质 High levels = High Conductivity 含量高=电导率高High Conductivity = Bad News 电导率高=坏消息,Conductivity of Interfering Substances 干扰物质的电导率,Reduces Charge on Pa

15、rticles 降低粒子表面的电荷 Reduces Affinity for Charged Polymers 降低带电聚合物表面的静电吸附力 Causes “Coiling” of Polymer Molecule 引起聚合物分子的卷曲 Reduces Efficiency of Polymer 降低聚合物的效能,Interfering Substances 干扰物质,Charge电荷 Most colloidal “interfering substances” are anionic（绝大部分“干扰物质”为阴离子） “Anionic Trash”（阴离子垃圾） High Amounts = Bad News 高含量=坏消息,Charge of Interfering Substances 干扰物质的电荷,Increases Cationic Demand 增加阳离子需求量 Competes with desire