【作者】 杨开吉；

【导师】 苏文强；

【作者基本信息】 东北林业大学 ， 林产化学加工工程， 2007， 硕士

【摘要】 两性聚丙烯酰胺由于其链节上同时含有正、负两种电荷基团，具有明显的“反聚电解质效应”和pH值适用范围广等优良特点，使其在造纸工业、石油开采、环境保护等方面有望得到广泛应用。但其常用制备方法都具有相应的缺点，如水溶液聚合制备的产品易交联，而反相乳液聚合制备的产品分子量分布宽等缺点。为了改善其使用性能，本研究采用反相微乳液聚合法制备了新型两性聚丙烯酰胺助留助滤剂。通过电导和目视相结合的方法研究了二甲基二烯丙基氯化铵（DADMAC）／丙烯酰胺（AM）／丙烯酸（AA）反相微乳液聚合体系的制备，得出环己烷为最佳油相、Span80-Tween60为最佳乳化体系、最佳单体浓度为55％、最佳单体配比为1.5∶7∶1.5、最小乳化剂用量为17.65％、油相和乳化剂的比值范围为3∶7～7∶3、单体溶液用量不大于33.33％（基于水相）。研究了单体浓度、单体配比、HLB值和电解质对反相微乳液体系稳定性的影响，结果表明，当单体浓度在40％～65％、HLB值在5.36～8.54变化时，反相微乳液体系比较稳定；单体配比中丙烯酰胺所占比例越大，体系越稳定；电解质NaAc的加入增强了DADMAC／AM／AA反相微乳液体系的稳定性。采用单因素实验探讨了EDTA加入量、充氮时间、搅拌速度、乳化剂用量、引发剂用量、单体浓度、反应温度和反应时间对两性聚丙烯酰胺（PDAA）分子量、转化率、乳液稳定性及其对纸料的助留助滤性能的影响。然后通过正交实验探讨了由单因素实验得到4个对反相微乳液影响较大的因素（反应温度、引发剂用量、反应时间和单体浓度）对PDAA的分子量、转化率和乳液稳定性及其对纸料的助留助滤性能的影响；由单因素实验和正交实验得到了制备PDAA的最优条件为：EDTA加入量0.5％、充氮时间为20min、搅拌速度为300r／min、乳化剂用量为18％（基于乳液质量）、引发剂用量为0.4％（基于单体）、单体浓度为54％（基于水相）、反应温度为24℃和反应时间为3h。通过研究pH值对PDAA产品的分子量、转化率、乳液的稳定性和对纸料的助留助滤性能的影响，得到pH值为7.12时，PDAA具有最理想的助留助滤性能。采用红外光谱和紫外光谱对PDAA结构进行了表征。采用电导法和目视法绘制了复配乳化剂、单体溶液、环己烷的三元相图，从稳定的反相微乳液区域选择动力学研究范围；通过动力学研究，得到聚合反应的表观活化能为9.84kJ／mol；探讨了反应温度、单体浓度、乳化剂用量和引发剂用量对聚合反应速率和PDAA分子量的影响，得到了聚合速率和分子量的动力学关系式分别为Rp^∝[M]^1.05[E]^0.21[I]^0.35和M_V∝[M]^1.18[E]^-1.16[I]^-0.24。通过扫描电镜观察了PDAA反相微乳液粒子形貌与PDDA水溶液粒子的形貌。研究了分子量、阳离子单体含量、纸料pH值和纸浆种类对PDAA助留助滤性能的影响；结果显示，当PDAA分子量为300万、阳离子单体含量为25％、纸浆pH值为8、纸浆种类为稻草浆时，PDAA具有最理想的助留助滤性能。另外，还探讨了PDAA与CPAM、CS、CHPG、PAE、PEO的协同作用。结果表明，PDAA和CPAM、CS、CHPG具有十分显著的协同助留助滤作用，与PAE具有一定的协同作用；而与PEO的协同助留助滤作用不明显。本研究采用反相微乳液聚合法制备的PDAA两性聚合物具有粒径小、分子量较大、分子量分布窄等优异性能，是一种理想的造纸助留助滤剂，对减少细小纤维流失、降低纸张生产成本和提高造纸企业的竞争力具有重要意义。更多还原

【Abstract】 Amphoteric-polyacrylamide-basedchemicals have been extensively applied in manyindustries including papermaking, oil and environmental protection. With both negative andpositive groups on their polymer chains and with striking "anti-polyelectrolyte" characteristics,these polymers are generally considered to be suitable for use in a wide range of pH conditionsin papermaking. However, there are many disadvantages associated with the commonly appliedpreparation procedures, for example, water-solution-polymerization-based polymer productsusually have strong tendency of crosslinking, and the molecular weight distribution ofinverse-emulsion-polymerization-based products are always too wide to be suitable for use inspecific applications. In order to overcome these disadvantages, development of novelamphoteric-polyacrylamide-based retention and drainage aids was explored.The preparation of inverse-microemulsion polymerization system of DADMAC/AM/AAwas studied by conductivity measurements and visual observations, the results show that, theoptimum oil phase, emulfying system, monomers Consistency and weight ratio of monomersare hexamethylene, SpanS0-Tween60, 55% and 1.5:7:1.5 respectively, and the minimumdosage of emulsifiers and maximum dosage of monomers are 17.65% and 33.33%. The resultsalso show that, the weight ratio of oil phase to emulsifiers should be well kept in the range of3:7～7:3. Effect of monomers cgnsistency, weight ratio of monomers, HLB and electrolytes onstability of inverse-microemulsion polymerization system were subsequently studied, and theresults show that, stable inverse-microemulsion polymerization system can be obtained whenthe monomers consistency and HLB are in the range of 40%～65% and 5.36～8.54 respectively,increased dosage of acrylamide and incorporation of NaAc into the system can further enhancethe stability.Effect of EDTA dosage, N₂ charging, stirring speed, dosage of emulsifiers, dosage ofinitiating agents, monomers consistency, reaction temperature and reaction time on molecularweight of amphoteric polymer, reaction yield, emulsion stability and retention and drainage aidproperties were intensively investigated. Orthogonal analytical method was then applied todiscuss the influence of reaction temperature, initiators dosage, reaction time and monomersconsistency on molecular weight, reaction yield, emulsion stability and retention and drainage aidproperties of the polymer products. The results show that, the optimum conditions for thepreparation of the polymer product are: EDTA dosage of 0.5%, N₂ charging time of 20min, stirringtime of 300r/min, emulsifier dosage of 18%, initiators dosage of 0.4%, monomers consistencyof 54%, reaction temperature of 24℃and reaction time of 3h. The results also show that, theoptimum pH is 7.12. The synthetic product of amphoteric polymer was then characterized by IR and UV.The ternary phase diagram of emulsifiers, monomers solution and hexamethylene wasobtained by conductivity analysis and visual observations, and the scope of study on kineticswas selected. According to the results of kinetics, the apparent activation energy of thepolymer reaction is 9.84kJ/mol. Effect of reaction temperature, monomers consistency,emulsifiers dosage and initiators dosage on reaction rate and molecular weight was thenstudied, and the equations were obtained (Rp^∝[M]^1.05[E]^0.21[I]^0.35, M_v^∝[M]^1.18[E]^-1.16[I]^0.24).SEM was then applied for the characterization of the morphology of emulsion particles and itsvariations during the polymerization reaction.The novel amphoteric polymer product was then applied as retention and drainage aids inmaking handsheets using straw pulp. The results show that, the optimum conditions are:molecular weight of 300 0000, cationic monomer content of 25%, furnish pH of 8.0. Thesynergic effect of the polymer product with cofactors including CPAM, CS, CHPG, PAE andPEO was then discussed, PDAA, CPAM, CS and CHPG are shown to be quite effective inperformance enhancement of retention and drainage, certain effect can be achieved with PAE,and the effect of PEO is not obvious.The polymer product developed in this work has many advantages, and it can besuccessfully applied as retention and drainage aid in papermaking. The application of theproduct can lower the manufacturing cost and enhance the competitiveness of the relevantpapermaking mills.更多还原