【作者】 李有金；

【导师】 任其龙；

【作者基本信息】 浙江大学 ， 化学工程与技术， 2008， 博士

【摘要】 烯基琥珀酸酐(Alkenyl Succinic Anhydride，ASA)是一种重要的造纸用施胶剂。现有的ASA乳化剂存在使用成本高或乳化性能差等不足。本文以二甲基二烯丙基氯化铵(DMDAAC)聚合物为基础，设计合成了一种兼具表面活性的疏水缔合型DMDAAC聚合物，并成功地将其作为ASA的乳化剂应用于造纸施胶过程，弥补了现有ASA乳化剂的不足，并拓宽了疏水缔合水溶性聚合物的应用领域。选择马来酸双酯型Gemini表面活性剂(MDE)代替常规的表面活性剂增溶疏水性单体甲基丙烯酸丁酯(MBA)或甲基丙烯酸辛酯(MOA)，并与DMDAAC、丙烯酰胺(AM)共聚，合成了DMDAAC-AM-MDE-MBA(或MOA)聚合物(PDAMM)。采用适宜的分析手段对PDAMM进行了结构表征。PDAMM具有两个玻璃化转变温度(Tg)，例如198．57℃和120．98℃，说明具有嵌段结构。研究了反应条件对聚合反应的影响规律。转化率随着引发剂的起始浓度和聚合反应温度的升高而增加，随着DMDAAC、MDE以及MBA(或MOA)的起始浓度增加而降低；阳离子度随着引发剂的起始浓度、聚合反应温度以及DMDAAC的起始浓度的升高而增加，随着MDE和MBA(或MOA)的起始浓度增加而降低；特性粘度随着引发剂起始浓度的升高出现先升高后降低的趋势，并随着聚合反应温度以及DMDAAC、MDE和MBA(或MOA)的起始浓度增加而降低。研究了PDAMM结构对疏水缔合性能及表面活性的影响规律。疏水性基团的疏水性越强，则疏水缔合性能越强；在疏水性基团含量低于饱和增溶量，得到的PDAMM水溶性好的条件下，疏水性基团含量越高，聚合物的特性粘度越高，疏水缔合性能也越强。PDAMM具有显著的表面活性，受疏水缔合性能的影响，其溶液表观表面张力在临界缔合浓度附近具有最低值，例如45．04mN／m(25℃)。研究了PDAMM结构对其乳化ASA能力的影响规律。PDAM(DMDAAC．AM-MDE共聚物)乳化得到的ASA乳状液在浓度为0．50％、25℃时的稳定时间低于30min，而相同条件下MBA含量为2．00％的PDAMM乳化得到的ASA乳状液稳定时间可达到15h。实验证明疏水性基团能促使PDAMM亲水性主链向ASA颗粒表面迁移并吸附包裹在颗粒表面，从而提高了乳状液的稳定性。根据乳化性能及施胶性能进行优化，得到ASA乳化剂PDAMM-4N。PDAMM-4N符合如下条件：DMDAAC=70．00％，AM=18．00％，MDE=10．00％，MBA=2．00％，特性粘度为0．40dL/g左右。采用PDAMM-4N乳化得到的ASA乳状液的粒径、粒径分布以及稳定性均能满足施胶的要求。研究了ASA／PDAMM-4N乳状液的应用技术。较佳的施胶条件是：ASA与PDAMM-4N按质量比1／1进行乳化，采用1％阳离子淀粉和0．02％阳离子聚丙烯酰胺双元助留，碳酸钙的加填量不高于25％，干燥温度为100-105℃，抄纸pH值是6-8。另外，ASA／PDAMM-4N乳状液在较强的剪切力和较宽的水质硬度范围均可使用。ASA／PDAMM-4N乳状液能满足工业应用要求，其直接施胶成本为39．14元／吨纸，略低于另一种常用中性施胶剂AKD在相同条件下的施胶成本。建立了ASA施胶数学模型。仅考虑ASA添加量w变化时的模型简化式为t=1/a-b·w，该模型拟合的相关系数为0．9788，平均绝对偏差为13．48％。仅考虑纸张定量G变化时的模型简化式为t=G~2/m-2·G，模型拟合的相关系数为0．9932，平均绝对偏差为11．12％。更多还原

【Abstract】 Alkenyl Succinic Anhydride （ASA） is an important paper sizing agent. The conventional emulsifiers of ASA have many drawbacks such as high cost or bad emulsifying ability. In the dissertation, a DMDAAC copolymer both have hydrophobically associating property and prominent surface activity, is designed and synthesized based on DMDAAC polymer, and successfully used in paper sizing process as emulsifier of ASA. The utilization covered many drawbacks related to conventional ASA emulsifier, and widen the application fields of hydrophobically associating water soluble polymers meanwhile.The target polymer is named as PDAMM and is copolymerized by DMDAAC, acrylamide （AM）, maleic di-ester type of Gemini surfactant （MDE）, hydrophobic monomer butyl methacrylate （MBA） or octyl methacrylate （MOA）. MDE used both as the solubilization aid of MBA or MOA, taking place of conventional surfactant, and as a monomer. Suitable methods are adopted in structure characterization of PDAMM. PDAMM has two glass transition temperature （Tg）, such as 198.57℃and 120.98℃, which shows it have a block structure.Various influencing factors during the preparation of PDAMM are studied. The conversion rate are increased by improving of the initial concentration of the initiator and the reaction temperature, decreased by improving of the initial concentration of DMDAAC, MDE and MBA （or MOA）; the cationic grade are increased by improving of the reaction temperature, the initial concentration of the initiator and DMDAAC, decreased by improving of the initial concentration of MDE and MBA （or MOA）; the intrinsic viscosity of the polymer shows a trend of rising first and falling afterward by improving of the initial concentration of the initiator, and decreased by improving of the reaction temperature, the initial concentration of DMDAAC, MDE and MBA （or MOA）.Influence of PDAMM’s structure to its hydrophobically associating property and surface activity are studied. Hydrophobically associating property is enhanced by increasing of content and hydrophobic property of hydrophobic monomer and intrinsic viscosity of the polymer when hydrophobic monomer is under its saturate solubilizing amount and PDAMM have good water soluble property. PDAMM has a prominent surface activity. The apparent surface tention of PDAMM solution is affected by its hydrophobically associating property, and has a minimum value at the critical association concentration, such as 45.04mN/m （25℃）.Influence of PDAMM’s structure to its property of emulsifying ASA is studied. When ASA concentration is 0.50%, ASA latex emulsified by PDAM （DMDAAC- AM-MDE copolymer） breaks in 30 minutes, while ASA latex emulsified by PDAMM （MBA content in PDAMM is 2.00%） remains unbroken in 15 hours. It is proved that the hydrophobic groups cause the main hydrophilic chain of PDAMM to migrate toward and wrap ASA particles, so that the stability of ASA latex is enhanced.ASA emulsifier PDAMM-4N is carried out by optimizing according to the emulsion capability and the sizing effects. PDAMM-4N have monomers contents of DMDAAC = 70.00%, AM = 18.00%, MDE = 10.00%, MBA = 2.00%, and has intrinsic viscosity value of around 0.40 dL/g. The equivalent particle size, radium size distribution and stabilities of ASA latex prepared by PDAMM-4N are all meet the sizing requests.Application technology of ASA/PDAMM-4N latex is studied. Suitable sizing conditions are: ASA is emulsified with the ratio of 1:1 to PDAMM-4N, retention aid system is composed of 1% cationic starch and 0.02% cationic polyacrylamide, filling amount of CaCO₃ is no higher than 25%, drying temperature is 100-105℃, sizing pH is between 6-8. Besides, ASA/PDAMM-4N latex can be used under a high sheering condition and within a broad range of water rigidity. ASA/PDAMM-4N latex can meet the industrial application requests, sizing with it cost 39.14 Chinese Yuan, lower than that of AKD, another commonly used neutral sizing agent.An ASA sizing model is firstly proposed. When only ASA dosage w is concerned, the modelhas a simplified expression of t =1/a-b·w, the related coefficients is 0.9788, and the meanabsolute deviation is 13.48%. When only fix quantity G is concerned, the model has a simplifiedexpression of t =G²/m-n·G, the related coefficients is 0.9932, and the mean absolute deviationis 11.12%.更多还原