【作者】 贾旭；

【导师】 张跃军；

【作者基本信息】 南京理工大学 ， 化学工程与技术， 2011， 博士

【摘要】 聚二甲基二烯丙基氯化铵(简称PDMDAAC)为二甲基二烯丙基氯化铵(简称DMDAAC)的均聚物,是一种典型的阳离子聚电解质,它在造纸、采煤、石油开采、纺织、印染、日用化妆品、水处理、生物和医药等领域有着广泛的用途。作为高分子聚合物,相对分子质量大小(以特征黏度值计)和分布直接决定了其性质和应用性能。本文基于已有的文献,介绍了PDMDAAC的结构和基本性质,归纳了其合成工艺、热稳定性和水溶液性质、电中和与絮凝架桥性能以及在诸多应用领域的研究进展,指出了存在的若干问题。进而,给出了本文研究工作的内容和意义。通过系统研究,本文工作获得以下几个方面的进展。第一高且系列相对分子质量PDMDAAC产物的制备,为进一步工业化放大生产奠定基础在制备高相对分子质量PDMDAAC产物方面,以本课题组已有工作为基础,采用引发剂反应前期一次性加入—三步升温的聚合反应新工艺,分别以工业单体、高纯工业单体和实验室两步法单体为原料,以过硫酸铵(APS)为引发剂制备PDMDAAC产物。经过正交优化和单因素实验,研究它们的最佳工艺条件及工艺因素,如单体起始含量w(DMDAAC)、引发剂用量m(APS):m(DMDAAC)、Na4EDTA用量m(Na4EDTA): m(DMDAAC)、聚合反应温度T1、T2和T3等对产物特征黏度值([η])和单体转化率(Conv.)的影响规律。在最佳工艺条件下,经过短时间反应9h,得到产物[η]最高值分别为：1.59、3.44和3.66dL/g,相应的Conv.分别为93.0%、100.0%和96.7%；经过乃阶段长时间反应102h,得到产物[η]最高值分别为2.42、4.69和4.21dL/g,相应的Conv.均为100.0%。以高纯工业单体和两步法单体为原料制得PDMDAAC产物的特征黏度值超过了文献报道的以APS为引发剂水溶液聚合法制备产物特征黏度值的最高值3.28dL/g。进一步比较了聚合反应工艺因素和单体的纯度对产物特征黏度值和单体转化率影响规律,为制备系列化特征黏度值的PDMDAAC产物打下基础。在制备系列化特征黏度值PDMDAAC产物方面,设计仅通过工艺因素w(DMDAAC)和m(APS):m(DMDAAC)、或者乃和聚合反应时间t的协同作用,制备出特征黏度值0.5-3.OdL/g或者3.0-4.5dL/g,特征黏度值间隔为0.5dL/g,单体转化率在98.0%以上的系列PDMDAAC产物。以上工作为高且系列化特征黏度值均聚物制备工艺的工业化放大和产物结构、性质和性能的研究奠定了基础。第二聚合反应若干机理问题研究,聚合反应中的现象和结果解释在引发剂一次性加入—三步升温聚合反应工艺的合理性证明方面,首先,通过对引发剂理论最佳用量和聚合反应的链增长速率进行估算,表明引发剂实际用量在理论最佳用量范围内；聚合反应链增长速率在链引发阶段迅速下降到一定值,此后在聚合反应全过程基本保持不变。其次,以转化率—时间变化曲线类型即聚合反应速率模型为判据,通过对不同聚合反应工艺方法的最佳聚合工艺条件下转化率—时间变化曲线类型的考察,表明引发剂一次性加入—三步升温聚合反应工艺最为接近匀速反应模型；在引发剂一次性加入—三步升温聚合反应方法下,通过不同聚合反应温度T1,T2和乃条件下的转化率—时间曲线类型的考察,表明经优化得到的最佳工艺条件的聚合反应速率最为接近匀速反应类型。由此,从引发剂用量、链增长速率和聚合反应模型方面,证明了研究得到的引发剂一次性加入—三步升温聚合工艺方法及其最佳聚合工艺条件的合理性。在杂质对聚合反应的影响研究方面,首先,根据自由基聚合原理,针对聚合反应过程中最关键的链引发步骤,设计了通过比较各种杂质和单体分子与APS引发剂初级自由基反应生成自由基产物的活泼性顺序,考察杂质对单体聚合反应活性影响的方法。采用量子化学B3LYP/6-31G*方法,对APS引发体系下,DMDAAC单体溶液中所含杂质与引发剂初级自由基可能形成的自由基产物的各种构型进行优化和振动分析,计算得到各杂质生成稳定自由基的反应活化能,结合氧化还原电位分析,得到各杂质对聚合反应的影响顺序为：二甲胺盐酸盐<二甲基烯丙基胺盐酸盐<烯丙醛<氯丙烯<烯丙醇<二甲胺<二甲基烯丙基胺,金属离子Na+<Cu2+<Fe3+。与此同时,设计了模拟实验验证方法,通过以杂质含量已知的高纯度两步法单体为原料,参考实际单体的杂质种类和含量,分别研究外加各类杂质的含量对PDMDAAC产物特征黏度值和单体转化率的影响规律。得到杂质对单体聚合反应活性影响顺序为：NaCl<二甲胺盐酸盐<氯丙烯≈二甲胺<二甲基烯丙基胺盐酸盐≈二甲基烯丙基胺<烯丙醛<烯丙醇<Fe3+<Cu2+。理论计算和模拟实验结果表明：杂质对单体聚合反应活性影响明显,是决定产物相对分子质量大小的关键性因素之一。该研究结果不仅给出了单体中所含杂质对单体聚合反应活性的影响规律和机理解释,而且为使用高纯度单体制备高特征黏度值PDMDAAC产物和单体质量标准的制定奠定了基础。在单体转化率(或残余单体量)对产物特征黏度值的影响研究方面,设计了外加单体至PDMDAAC精制产物中以模拟不同转化率产物的方法,用于研究单体转化率对产物特征黏度值的影响规律。得到了定量表征单体转化率Conv.(或残余单体量)对产物特征黏度值[η]影响的线性拟合方程lg[η’]= lg[η]+lgConv.’(Conv.’<50.0%)。该研究结果为通过提高单体转化率来提高PDMDAAC产物平均相对分子质量(特征黏度值)提供了一种有效的途径。第三研究高且系列化特征黏度值的线性和交联PDMDAAC的结构、性质和性能在结构表征方面,采用FTIR和NMR的方法对PDMDAAC产物进行结构表征,测试结果表明线性PDMDAAC的相对分子质量越高,单位质量产物所含的端基双键数越少；半固态NMR谱图表明,交联产物由于支化和交联副反应的发生,-CH2-和(?)的峰面积比例明显增加。在热稳定性质测定方面,采用TG-DSC-MS和TG-DTA的方法研究了高且系列化特征黏度值PDMDAAC的热分解动力学、热力学和分解机理,测定结果表明：均聚物PDMDAAC产物的热分解有两个阶段,而单体的热分解只有一个阶段。随着产物特征黏度值的增加,总的热分解活化能也随之增加；交联产物与线性产物热稳定性接近。应用实验测得的参数,采用Coast-Redfern方法计算得到PDMDAAC热分解分为两个阶段,均为一级反应；采用Ozawa方法计算得到特征黏度值为3.83dL/g的PDMDAAC产物的两个阶段分解平均活化能Ea分别为124.1和：211.1kJ/mol。TG-DSC-MS谱图表明：PDMDAAC分解第1阶段主要生成气体为氯胺,第Ⅱ阶段主要生成气体为甲烷、乙炔和丙烷。该研究结果突破了至今仅有的对单一且低特征黏度值PDMDAAC的热力学和动力学方面研究工作的局限,在此基础上提出了PDMDAAC的热分解机理以及相对分子质量大小对其热稳定性的影响规律。在溶液性质研究方面,采用GPC-MALLS方法测定了以c(NaCl)=0.5mol/L为溶剂,25℃下PDMDAAC分子的分子形态和尺寸,研究结果表明：PDMDAAC产物特征黏度值越高,对应的产物相对分子质量和均方根旋转半径Rg越高、产物的流出时间越短、分子链越柔顺。同时,测定了系列窄分布PDMDAAC的K、α值,得到Mark-Houwink方程式为[η]=1.01×10-2M0.767([η]<1.57dL/g)以及[η]=0.313 M0.5044(1.57dL/g<[η]<4.49dL/g)。采用旋转黏度计的方法,以H20为溶剂,测定了不同温度下系列特征黏度值PDMDAAC的表观黏度与产物质量分数的变化规律,研究结果表明：PDMDAAC产物特征黏度值和质量分数越高,测量温度越低,测得的溶液表观黏度越大。研究得到的Mark- Houwink方程适用相对分子质量范围超过已有文献报道的范围,为更宽产物相对分子质量范围内重均相对分子质量和特征黏度值之间的换算提供便利。在混凝性能研究方面,设计了研究高且系列化特征黏度值PDMDAAC产物作为混凝助剂时的电中和与吸附架桥能力的实验方法。以自制的高岭土模拟水为研究对象,以上清液浊度、zeta电位为衡量指标,采用特定条件下烧杯混凝搅拌实验,研究了单体DMDAAC和不同特征黏度值PDMDAAC对悬浮胶体电中和能力及变化规律。同时,以自制的硅藻土模拟水为研究对象,以絮团沉降速率、上清液透过率为衡量指标,采用特定条件下的量筒絮凝沉降实验,研究了单体DMDAAC和不同特征黏度值PDMDAAC对悬浮凝聚物的吸附架桥能力及变化规律。结果表明：在保持处理后高岭土模拟水上清浊度相近的条件下,悬浮胶体的zeta电位随PDMDAAC的投加量的增加而线性增加,特征黏度值对其的影响却不明显；单体DMDAAC的投加量增加,对zeta电位的变化近无影响。然而,在硅藻土模拟水的絮凝沉降实验中,相同投加量情况下,随着PDMDAAC特征黏度值的增加,絮团沉降速率、絮团大小和上清液透过率明显增加；单体不能使悬浮凝聚物产生沉降效果。由此说明,PDMDAAC用作混凝助剂时对电中和的贡献主要在于其投加的量,而对絮凝架桥作用的贡献则还有产物的相对分子质量大小。该研究工作,给出了PDMDAAC在混凝过程中作用的可能机理描述,为其作为混凝助剂在强化混凝处理过程中的机理解释奠定基础。第四PDMDAAC制备工艺的中试放大及其产品的应用研究例在PDMDAAC制备工艺的中试放大方面,以高纯工业单体为原料,APS为引发剂,经过实验室逐级放大后,最终在两条年产100t的中试生产线上对PDMDAAC制备工艺进行中试放大并实现产品的批量稳定生产,制得PDMDAAC产品特征黏度值最高为3.36dL/g,特征黏度值从0.5-3.5dL/g以0.5dL/g为间隔形成了系列化产品。在系列化特征黏度值PDMDAAC的应用方面,以微污染原水强化混凝处理中聚合氯化铝PAC/PDMDAAC复合混凝剂的应用为例进行介绍。将PDMDAAC产物与常用无机盐PAC混凝剂复合制得含不同特征黏度、不同无机盐PAC/PDMDAAC配比的系列化稳定型复合混凝剂,选择有代表性的微污染水源水长江水和太湖水为处理对象,首先进行现场实验室混凝烧杯实验,进一步在中试模拟生产线上进行了太湖含藻水的强化混凝除藻工艺的中试放大研究,最终在水厂的实际生产线上对微污染长江水进行强化混凝工艺的放大研究。中试模拟生产线和生产线上的研究结果与实验室实验结果一致。研究结果表明：PAC/PDMDAAC复合混凝剂具有良好的混凝脱浊和除藻的效果；在相同的PAC投加量下,PDMDAAC的特征黏度值或者复合比例越高,处理后测定的出水浊度和藻的去除率越高；在达到相同的处理效果时,PDMDAAC的特征黏度值或者复合比例越高,所需的无机盐PAC投加量越少。该研究结果不仅为微污染原水处理后出水水质安全性的保障和未来优质水制备新工艺的储存奠定了基础,而且为铝盐投加量的减少和制水工艺成本的降低提供了可能。同时,在水处理应用方面证实了高相对分子质量PDMDAAC的重要应用价值。上述完成的工作,丰富了PDMDAAC在高且系列化特征黏度值产物的合成工艺、聚合反应机理及结构与性质关系等方面的研究成果,为在该领域基础理论研究的展开、生产工艺的产业化推广和衍生产品的应用研究,奠定了良好的基础。更多还原

【Abstract】 Poly(dimethyldiallylammonium chloride) (PDMDAAC) is a homopolymer product of dimethyldiallylammonium chloride (DMDAAC) which is a typical cationic polyelectrolyte. It has wide applications in many fields, such as paper making, coal mineral, petroleum beneficiation, dyeing, domestic chemicals, water treatment, biochemical, pharmaceuticals and so on. As a polymer, its properties and performances directly depend on its average molecular weight (i.e. intrinsic viscosity) and distribution. The structure and basic properties of PDMDAAC were introduced. Then, the research progresses about the preparation methods, thermal stability, solution properties, charge neutralization, bridging-netting performance and applications of PDMDAAC were reviewed according to the literatures. The exist problems in the researches were pointed out. Based on these, the research contents and their significations in this dissertation were illuminated. The obtained research progresses in this dissertation are showed as following.The products of PDMDAAC with high and serial molecular weight and their preparation processesAs to the preparation of PDMDAAC products with high molecular weight, three kinds of monomer with different purity were used as raw materials, and APS as initiator. Under the preparation method, that the APS was added in a lump and polymerization temperature was increased stepwise to complete the polymerization gradually, the PDMDAAC product was synthesized. The three monomers were industrial monomer, industrial monomer with high purity and laboratorial monomer. The influences of w(DMDAAC), m(APS):m(DMDAAC),m(Na4EDTA):m(DMDAAC), and polymerization temperature (T1,T2and T3) on the intrinsic viscosity values ([η]) of product and monomer conversion (Conv.) in product were studied, based on the orthogonal optimal experiments. The highest intrinsic viscosity values ([η]max) of PDMDAAC products prepared by using the three monomers at their optimum conditions were 1.59,3.44 and 3.66dL/g with the Conv. of 93.0%,100.0% and 96.7%, respectively. And they could achieve 2.42,4.69 and 4.21dL/g with the 100.0% Conv. in all products, respectively, by prolonging the reaction time from 3h to 102h at maintaining temperature T3. It was worthy to note that the maximum [η] of PDMDAAC in this dissertation was higher than the maximum [η] reported in literatures. Moreover, the effects of preparing conditions and monomer purity on the [η] and Conv. were investigated, respectively. They all could be the foundation for preparation of PDMDAAC products with serial molecular weight.As to the preparation of PDMDAAC products with serial intrinsic viscositie values, two methods, by controlling w(DMDAAC) companying with m(APS):m(DMDAAC), or T3 companying with the maintaining time t were designed effectively to obtain the products with serial [η] ranged from 0.1 dL/g to 3.0dL/g and 3.0 dL/g to 4.5dL/g, and Conv. were higher than 98.0%. They all could be the well fundamental for the further industrial production of PDMDAAC and the researches on structures, properties and performances of the products with serial [η].The studies of several polymerization mechanismsAs to the rationality demonstration for the preparation method mentioned above, the theoretical calculation showed that the adding amount of initiator under the optimum preparation condition was in the optimum range of theoretical estimation, and the chain propagation rate of polymerization was almost constant a short period of time after initiation. Then, the comparison with different preparing methods showed that, the polymerization rate variation of the preparation method, "The initiator was added in a lump and the polymerization temperature increased stepwise", was more close to constant "reaction time-conversion curve" type. Moreover, the comparison of reaction temperatures with different T1, T2 and T3, by using the preparation method showed that, the polymerization rate variation with the temperatures T1, T2 and T3 under the optimal reaction condition was more close to constant "reaction time-conversion curve" type. Therefore, the rationalities of both the preparation method and its optimum reaction condition were demonstrated and explained, by the calculation of the adding amount of initiator, chain propagation rate of polymerization and the comparison of the polymerization rate.As to the effects of impurities contained in monomer on the polymerization activity, a method, using the activity order of impurities and monomer molecule reacting with the initiator radical to represent the influence order of the impurities on the polymerization was designed, on the basis of the radical polymerization theory that the chain initiation was the key step in polymerization, and the impurities contained in monomer solution could react with the initiator radical of APS to produce radical products. The fully optimized structures and thermodynamic properties of different radical products were computed at the B3LYP/6-31G* level. The obtained influence order of the impurities was, dimethyl amine hydrochloride<dimethylallyl amine hydrochloride < allyl alderhyde < allyl chloride <allyl alcohol < dimethyl amine <dimethylallyl amine and Na+ <Cu2+ <Fe3+, based on the comparison of activation energies and the redox potentials. Meanwhile, a simulation experiment method was designed. In the experiments, the effects order of impurities for certain kinds and with different amounts in simulated monomer solutions on the [η] of PDMDAAC products and Conv. in PDMDAAC products could represent the influence order of the impurities on polymerization activity, according to the radical polymerization theory. Each simulated monomer was prepared by quantitatively adding a certain kind of impurities into the raw monomer with high purity synthesized in lab. The polymerization was carried out under the optimum condition. The obtained influence order of the impurities was, NaCl< dimethyl amine hydrochloride< allyl chloride≈dimethyl amine<dimethylallyl amine hydrochloride≈dimethylallyl amine< allyl alderhyde < allyl alcohol <Fe3+ <Cu2+. The results of quantum chemistry calculation and simulation experiments indicated that the impurities in monomer solution had significant influences on the polymerization, so the purity of monomer was a key factor to influence the molecular weight of PDMDAAC products. These researches not only indicated the effects of impurities in monomer solution on the polymerization activity, but also well guided to obtain the products with high molecular weight by using monomer with high purity and helped to set up the quality standard for monomer products.As to the effects of monomer conversion rates on the [η] of PDMDAAC product, a method was designed that the simulation PDMDAAC products with different Conv. was prepared by adding the different amount of monomer to the purified PDMDAAC products with different intrinsic viscosities. The simulation products could be used to study the effects of residual monomer amounts on the [η] of practical PDMDAAC products. The results showed that the influences could be represented as the equation, lg[η’]=lg[η]+lg Conv.’. This law indicated that it was an effective way to obtaining high molecular weight PDMDAAC products by the increase of Conv..The studies of the structures, properties and performances of liner PDMDAAC with serial [η] and crosslink PDMDAACAs to the structure of serial PDMDAAC products, the FTIR and NMR were used to characterization. The spectra showed that higher the molecular weight of linear product was, the less the terminal double bond had in unit weight. The semi-solid NMR spectra showed that the areas ratios of the peaks belonging to the -CH2- of the main chain and to—CH- of branch chain in the crosslink molecular increased significantly when branching and crosslinking side reaction occurred in the products.As to the thermal stabilities of serial PDMDAAC samples, TG-DSC-MS and TG-DTA were used to determinate the kinetics, thermodynamics and mechanisms of thermal decomposition of PDMDAAC samples. The results showed that there were two decomposition stages for PDMDAAC, while there was only one for its monomer DMDAAC. The decomposition activation energy Ea increased with the molecular weight of PDMDAAC. The decomposition characteristics of crosslink products were similar to thant of the linear product. The calculation results by using the Coast-Redfern method indicated that there were two decomposition stages for PDMDAAC, and the reaction order of each stage was one. The Ea of PDMDAAC with [η] 3.83dL/g calculated by Ozawa method was 124.1kJ/mol and 211.1kJ/mol for each decomposition stage. The decomposition gas products were mainly NH2Cl for the first stage and were mainly CH4, C2H2 and C3H8 for the second stage, which verified by the joined analysis results of TG-DSC-MS. The results broke through the limitation of research results in literatures, which used only one PDMDAAC sample with low molecular weight for the studies of kinetics and thermodynamics. Meanwhile, the results demonstrated the mechanisms of thermal decomposition of PDMDAAC, and the effects of intrinsic viscosity of PDMDAAC products on their thermal stabilities.As to the solution properties of serial PDMDAAC samples, GPC-MALLS was used to determinate the molecular conformations and sizes of PDMDAAC in the solvent of c(NaCl)=0.5mol/L at 25℃. The results showed that the higher the intrinsic viscosity value of the sample was, the higher the molecular weight and Rg was, the shorter the eluting time was, and more compliant of the sample molecular chain was. Meanwhile, the constants k and a were calculated by using GPC-MALLS to determine the molecular weights and intrinsic viscosities of serial PDMDAAC samples with narrow distribution. The obtained Mark-Houwink equation was [η]=1.01×10-2M0767([η]<1.57dL/g) and [η]= 0.313 M05044 (1.57dL/g< [η]<4.49dL/g). Moreover, the effects of PDMDAAC mass concentration and testing temperature on the apparent viscosity of PDMDAAC water solution were studied by using circumgyrate viscometer. The results showed that the apparent viscosity increased with the molecular weight of PDMDAAC samples and the mass concentration, while decreased with the temperature increasing. The Mark-Houwink equation could be well applied to calculate the molecular weight of PDMDAAC samples in a much wilder range.As to the flocculation performances of PDMDAAC products, two methods for studying the abilities of charge neutralization to the suspending colloid and for bridging-netting to the suspending coalescence were designed, respectively. In the experiments of the charge neutralization, the water containing Kaolin was used as simulated water, and the changes of turbidity and zeta potential of the supernatant with the adding amount of DMDAAC and PDMDAAC were used as evaluation indexes for the abilities of charge neutralization. When the turbidity of supernatant after treatment was controlled almost unchanged, the results showed that the zeta potentials of suspended particles increased obviously with the adding amount of PDMDAAC, while they increased inconspicuously with the intrinsic viscosity of PDMDAAC. However, zeta potential kept almost unchanged when adding amount of DMDAAC increased. In the experiments of the bridging-netting, the water containing Diatomite was used as simulated water. The changes of the settlement rate, floc size and the transmittance of supernatant with the adding amount of DMDAAC or PDMDAAC were used as evaluation indexes for the abilities of bridging-netting. The results showed that the settlement rate, floc size and the transmittance of supernatant increased with the intrinsic viscosity of PDMDAAC, when the added amount of PDMDAAC was kept the same. However, there was no obvious flocculation happened after the monomer DMDAAC added. Therefore, the performances of PDMDAAC used as the coagulant were both the charge neutralization which mainly depended on the adding amount of PDMDAAC and the bridging-netting which specially depended on the molecular weight of PDMDAAC besides its adding amount. These completed researches offered a possible description for working mechanisms of PDMDAAC in coagulation, which could be a fundamental for the explanation of working mechanism of the composites coagulant containing PDMDAAC in the enhanced coagulation of raw water.The examples for scaled-up of preparing processes of PDMDAAC and application of PDMDAAC products in raw water treatmentAs to the scaled-up of preparation processes of PDMDAAC products with high and serial molecular weight, the products were well manufactured in two scaled-up lines, each with the production ability of 100t per year, by using the industrial monomer with high purity as the raw material, APS as the initiator under the obtained optimal conditions. The highest [η] of PDMDAAC product was 3.36dL/g and its serial intrinsic viscosity values could range from 0.5dL/g to 3.36dL/g.As to the application of PDMDAAC, the serial [η] of PDMDAAC products were composited with poly aluminum chloride (PAC) to form composite coagulants. The examples for the application of the composite coagulants in raw water treatments were showed. The application researches were made by the Jar tests in lab, simulated production line and drinking water production line in factory, step by step. The composite coagulants contained different mass ratios of PAC and PDMDAAC products with serial[η]. The treated raw water in application researches included the water of Yangzi River and Tai Lake, which represented the typical slight polluted river and lake water in China, respectively. The successful results of application in the scaled-up and practical lines showed that the composite coagulant PAC/PDMDAAC had good performances on the removal of turbidity and algae in the process of enhanced treatment of raw water. For adding the same amount of PAC, the higher the [η] or mass ratio of PDMDAAC in composites coagulants, the better the performance of turbidity and algae removal were. For achieving the same treatment efficiency, the higher the [η] or mass ratio of PDMDAAC in composites coagulation was, the less amount of the inorganic coagulants PAC needed. The research results for the application of PDMDAAC in slight polluted raw water treatment could not only be the guarantee for the safety of the drinking water after treatment and the reservation of new technology for raw water treatment for the production of higher quality in the future, but also offer the possibilities of decreasing the adding amount of PAC and the cost for preparing drinking water.The completed researches in this dissertation have enriched the knowledge of processes, mechanisms, and the relationships between structure and properties of PDMDAAC with high and serial intrinsic viscosity values, which could be a well fundamental for the further researches both on theories and on applications of PDMDAAC.更多还原