PREPARATION AND CHARACTERIZATION OF AFFINITY POLYMER BASIC MICROSPHERES BY SOAP-FREE EMULSION POLYMERIZATION

Poly(styrene-co-glycidyl methacrylate) latex microspheres with uniform size and high-density epoxy groups on the surface were prepared by soap-free emulsion polymerization with batch wise operation mode in the presence of 2.2′- azobis(2-methylpropionamidine) dihydrochloride as an initiator.The kinetics of soap-free emulsion polymerization and the effects of polymerization factors were examined.In addition,the optimum polymerization conditions of poly(styrene-co- glycidyl methacrylate) latex microspheres for...

Preparation of Self-crosslinked Fluorocarbon Polymer Emulsion with Core-shell Structure by the Method of Soap-free Emulsion Polymerization

Using methyl methacrylate （MMA）, butyl acrylate（BA） and hexafluorobutyl acrylate（HFBA） as main raw materials, we prepared self-crosslinked fluorocarbon polymer emulsion with core-shell structure via soap-free emulsion polymerization when the conception of particle design and polymer morphology was adopted. Moreover, the influence of mole ratio of BA to MAA, pH value on the oligomer was studied. And the effects of the added amount of oligomer, self-crosslinked monomer and HFBA, mass ratio of BA to MMA, reaction temperature and the initiator on the polymerization technology and the performance of the product, were investigated and optimized. The structure and performance of the fluorocarbon polymer emulsion were characterized and tested with FTIR, TEM, MFT and contact angle and water absorption of the latex film. The experimental results show that the optimal conditions for preparing fluorocarbon polymer emulsion are as follows： for preparing the oligomer, tool ratio of BA to MAA is equal to 1.0 ： 1.60, and pH value is controlled within the range of 8.0 and 9.0; for preparing fluorocarbon polymer emulsion, the added amount of oligmer[P（BA/MANa）] is 6%; mass ratio of BA to MMA is 40 ＂ 60; the added amount of self-crosslinked monomer is 2%, the added amount of HFBA is 15 %; reaction temperature is 80 ℃; the mixture of potassium persulfate and sodium bisulfite is used as the initiator. The film-forming stability of the fluorocarbon polymer emul- sion and the performance of the latex film, which is prepared with the soap-free emulsion polymerization, are better than that prepared with the conventional emulsion polymerization.

Influences of Electrolytes on the Soap-free Emulsion Copolymerization of St-MMA-AA

Monodisperse functional polymer microspheres with different particle size and with clean surface were prepared by batch soap-free emulsion polymerization of styrene, methyl methacrylate and acrylic acid in the presence of salts, and the influences of type and amount of electrolytes on polymerization process and particle morphology were investigated. Results showed that there was a critical concentration for different electrolyte to make polymerization process and the resultant emulsion stable, and the particle size increased with the increase of electrolyte concentration. The effect of metal ions was Ca^2＋〉〉K^＋〉Na^＋〉Li^＋, and the effect of haloids was Br〉Cl〉F. Keywords： Electrolyte, soap-free emulsion polymerization, polystyrene, latex particle morphology.

INFLUENCES OF ACID POST-TREATMENT ON THE MORPHOLOGY OF SOAP-FREE P(MMA-EA-MAA)PARTICLES PREPARED BY SEEDED EMULSION POLYMERIZATION

Soap-free poly（methyl methacrylate-ethyl acrylate-methacrylic acid） latex particles with narrow size distribution were synthesized by seeded emulsion polymerization, and the porous particles were created by a stepwise alkali/acid treatment method. Effects of acid treatment conditions on the particle morphology were investigated. Results show that one to three pores were formed inside most of particles after post-treatment. At pH 7.0, when the treatment temperature was lower than 70℃, the size of particles and the volume of pores remained almost unchanged, and these two values increased significantly when the temperature was higher than 70℃. Both the particle size and the pore volume decreased with the increase of initial pH value and treatment time in the acid treatment. As the pH was below 4.0 and the treatment time was longer than 180 min, the particles shrunk in size.

Emulsion Polymerization of Vinyl Acetate in the Presence of a New Cationic Surfactant

In this study, the emulsion homopolymerization system containing vinyl acetate, potassium persulfate, a new cationic polymeric surfactant and water was studied by the applying semi-continuous emulsion polymerization process. The effects of new polymeric emulsifier on the physicochemical properties of obtained vinyl acetate latexes were investigated depending on vinyl acetate percentage in the polymerization recipe, and two thermal initiators in homopolymerization.

Synthesis of ABA Type Block Copolymers of Poly(Ethylene Glycol)and Poly(Dodecyl Vinyl Ether)and Its Using as Surfactant in Emulsion Polymerization

A poly(ethylene glycol) (PEG) based macroinitiator (MI) with terminal chloride atom at both ends was prepared by the reaction of PEG-400 with chloroacetyl chloride and used for the cationic polymerization of dodecyl vinyl ether (DVE) yielding ABA type block copolymer. The block copolymer was then used as the surfactant for the emulsion polymerization of vinyl acetate and styrene in the presence of potassium persulfate as an initiator. The effects of new polymeric emulsifier on the physicochemical properties of obtained latexes were investigated depending on surfactant percentage in homopolymerizations.

Synthesis of submicron-sized peanut-shaped poly(methyl methacrylate)/polystyrene particles by seeded soap-free emulsion polymerization

Submicron-sized peanut-shaped poly（methyl methacrylate）/polystyrene （PMMA/PS） particles were successfully synthesized by seeded soap-free emulsion polymerization of styrene on the spherical crosslinked PMMA seed particles. The obtained peanut- shaped particles showed a novel internal morphology： PS phase formed one domain which linked to the other domain having PMMA core encased by PS shell.

PREPARATION OF MICRON-SIZED NONSPHERICAL POLYSTYRENE/POLY(STYRENE-co-ETHYLENEGLYCOL DIMETHACRYLATE) PARTICLES BY SEEDED SOAP-FREE EMULSION POLYMERIZATION

Micron-sized nonspherical polymer particles having different morphologies were synthesized by seeded soap-free emulsion polymerization of styrene （St） and ethyleneglycol dimethacrylate （EGDMA, used as a crosslinker） on spherical, linear polystyrene （PS） seed particles. The morphology of the resulting PS/poly（St-co-EGDMA） particles was dependent on the crosslinker concentration and polymerization temperature.

A New Kind of Void Soap-free P(MMA-EA-MAA) Latex Particles

Soap-free P(MMA-EA-MAA) particles with narrow size distribution were synthesized by seeded emulsion polymerization of methyl methacrylate (MMA), ethyl acrylate (EA) and methacrylic acid (MAA), and large voids inside the particles were generated by alkali posttreatment in the presence of 2-butanone. Results indicated that the size of void and the particle volume were related with the amount of 2-butanone. The generation mechanism of voids was proposed.

高取代度阳离子淀粉基苯丙乳液的合成和应用研究

以苯乙烯(St)、丙烯酸正丁酯(BA)、丙烯酸叔丁酯(tBA)为单体,H2O2-FeSO4为引发体系,高取代度阳离子淀粉(HCS)为乳化剂,开展了苯丙表面施胶剂的无皂乳液聚合。探讨了HCS的用量、分子量(以特性黏度表示)、取代度对乳液聚合的影响,使用多种方法评价了乳液的理化性能与应用性能。所制备得的高取代度阳离子淀粉基苯丙乳液胶粒平均粒径小(126.2 nm)、正电性强(Zeta电位为25.8 mV)、贮存稳定性优良;将其应用在瓦楞原纸上,施胶纸张的Cobb值为21.6 g/m^(2),水滴接触角达121.6°,与低取代度阳离子淀粉基苯丙乳液相比,其应用效果具有明显优势。研究对其能赋予纸张更佳施胶效果的原因也提出了机理性的解释。

Pickering emulsion polymerization of styrene stabilized by nanocrystalline cellulose

In this work,polystyrene-based oil-in-water Pickering emulsion stabilized by nanocrystalline cellulose(NCC)was formulated.The NCC was prepared by sulfuric-acid-catalyzed hydrolysis of microcrystalline cellulose,with a yield of 60%and an average particle size of about 152.9 nm.When the content of NCC was 5 g/L,the surface tension was 54.58 mN/m,and stable styrene-based Pickering emulsion was prepared using NCC as the stabilizer.The presence of NCC particles in the emulsion system resulted in high resistance against creaming.Due to improved stability,the conversion efficiency of styrene was higher in the polymerization process of the styrene-based Pickering emulsion.

阳离子型聚丙烯酸酯抗菌乳液的合成及性能

以丙烯酸二甲氨基乙酯(DMAEA)和溴代十四烷(TTDB)为原料,制备了可聚合阳离子抗菌单体,并通过乳液聚合的方法制得阳离子型聚丙烯酸酯抗菌乳液。探讨了抗菌单体用量、硬单体种类、交联单体种类和用量对乳液性能以及整理棉织物抗菌性能的影响。结果表明:当乳化剂十六烷基二甲基苄基氯化铵(1627)与异构十三醇聚氧乙烯醚(E1309)的质量比为1∶1,质量分数为1%;软单体丙烯酸丁酯(BA)与硬单体苯乙烯(ST)物质的量比为4∶1,质量分数为24.5%;引发剂偶氮二异丁脒盐酸盐(AIBA)质量分数为1%;交联单体双丙酮丙烯酰胺(DAAM)与抗菌单体质量分别为软硬单体总质量的3.6%和20%时,所制得的乳液性能稳定,用其整理的棉织物对大肠埃希菌和金黄葡萄球菌具有良好的抗菌效果,水洗10次后,抑菌率分别为93.0%和95.0%。

反相乳液聚合法制备阳离子聚丙烯酰胺乳液及其应用

以丙烯酰胺(AM)、甲基丙烯酰氧乙基三甲基氯化铵(DMC)为功能性单体,在氧化-还原引发体系下,通过反相乳液聚合方法,成功制备了乳液型阳离子聚丙烯酰胺。对比了自制乳液样品(CPAMZ1)、CPAMZ1与无机絮凝剂聚铝(PAC)复配乳液样品和市售成熟乳液产品(ASC1010)在市政污泥废水处理中的应用效果。研究结果表明,CPAMZ1处理污泥的效率高于ASC1010,以透光率为指标,前者絮凝效果增强了20.58%;对比CPAMZ1样品,CPAMZ1/PAC复配液(CP/PAC)的絮凝效果增强了13.64%。在污泥废水处理中,乳液型絮凝剂适合与无机絮凝剂进行配合使用。

P(VAc-MMA-DM)阳离子聚合物乳液的合成及其在造纸增强中的应用

以醋酸乙烯酯 (VAc)、甲基丙烯酸甲酯 (MMA)和甲基丙烯酸二甲胺乙酯 (DM)为原料 ,采用无乳化剂乳液聚合法合成出了一系列 VAc- MMA- DM阳离子共聚物乳液 ,测定了此乳液的转化率和稳定性 ,找到了合成最稳定且转化率最高的 VAc- MMA- DM阳离子共聚物乳液的配方和条件 ;由电镜测得此乳液为球形粒子 ,粒径约为 0 .1μm。将 VAc- MMA- DM阳离子共聚物乳液加到竹浆或纸浆中 ,通过对纸张的环压强度、耐破度、撕裂度等的测定 ,发现当乳液的用量为 1.0 %时 ,其增强性能最好。

VAC与甲基丙烯酰氧乙基三甲基氯化铵无皂乳液共聚合动力学研究

研究了醋酸乙烯酯 (VAC)与甲基丙烯酰氧乙基三甲基氯化铵 (DMC)无皂乳液共聚合动力学 ,考察了引发剂偶氮二异丁基脒盐酸盐 (AIBI)浓度、单体浓度、温度等因素对聚合反应速率的影响 ,得到单体总浓度和引发剂浓度影响反应速率的动力学方程为 :Rp=k1 [M]0 6 3[AIBA]1 0 ;各单体浓度影响反应速率的动力学方程为 :Rp=k2 [VAC]0 1 6 [DMC]0 89.聚合表观活化能为 4 4 0 1kJ·mol- 1 ,初步探讨了聚合反应机理 .

水性涂料用阳离子聚丙烯酸酯乳液的合成

采用种子预乳化半连续法,合成了固含量高的阳离子型聚丙烯酸酯乳液。考察了在乳液聚合中反应性乳化剂、引发剂种类及功能单体含量对乳液聚合稳定性及乳液性能的影响。结果表明:在乳液聚合体系中,功能单体HEA含量为1%最佳;合理的反应性乳化剂用量及加入方式可使乳液固含量达到41%;选用AIBN与BPO复配的引发剂制备的乳液性能良好。

阳离子聚丙烯酰胺的反相乳液聚合

以丙烯酰胺(AM)和丙烯酰氧乙基三甲基氯化铵(DAC)为单体,Span80-Tween80为复合乳化剂,液体石蜡为连续相,通过反相乳液聚合法制备阳离子型高分子聚丙烯酰胺。研究了油水体积比对聚合物特性粘度的影响,乳化剂用量对聚合物特性粘度的影响,单体用量对聚合物特性粘度的影响,阳离子度对聚合物特性粘度的影响及引发剂用量对聚合物特性粘度的影响。结果表明:在油水体积比为1∶1.6、乳化剂用量为30%、单体用量为30%、阳离子度为60%即n(AM)∶n(DAC)为2∶3,引发剂用量为0.15%的条件下,得到的聚合产物粘度较大且具有良好的稳定性和溶解性。对产物进行了红外结构表征,并研究了产物的污泥脱水性能,获满意结果。

反相乳液聚合制备高相对分子质量和高阳离子度的聚丙烯酰胺

以丙烯酰胺(AM)和丙烯酰氧乙基三甲基氯化铵(DAC)为单体,采用反相乳液聚合制备了高相对分子质量和高阳离子度的聚丙烯酰胺(P(AM-DAC);考察了乳化剂和引发剂的种类,乳化剂、引发剂、AM和阳离子单体DAC用量,乳化剂亲水亲油平衡值(HLB)对P(AM-DAC)的特性黏数的影响。实验结果表明,含脂肪醇聚氧乙烯醚(MOA)-3/MOA-9复合乳化剂的乳液体系稳定性最好,偶氮二异丁基脒盐酸盐(V-50)的引发效果最好。采用正交实验确定了最佳合成条件:MOA-3/MOA-9复合乳化剂质量分数(基于反应体系的总质量)和HLB值分别为4.8%和8.6、AM和DAC的总质量分数为40%(基于反应体系的总质量)、V-50质量分数为0.09%(基于单体的总质量)、DAC摩尔分数55%(基于单体总的物质的量)。在最佳合成条件下合成的P(AM-DAC)的特性黏数最大(1378.7 mL/g),对含聚污水的絮凝效果好。

PVST乳液的合成及在造纸增强中的作用

以乙酸乙烯酯 (VAC) ,苯乙烯 (ST)和氯化甲基丙烯酸三甲胺乙酯 (TMC)为原料 ,采用无乳化剂乳液聚合法 ,合成出了一系列VAC ST TMC阳离子共聚物 (PVST)乳液 ,测定了乳液的稳定性和转化率 ,找到了合成PVST的最优配方和条件。根据电镜观测 ,此乳液为球形粒子 ,粒径约为 60～ 2 0 0nm。把PVST乳液加到竹浆中 ,测定纸张的耐折度 ,撕裂强度和环压强度等。当PVST的用量为 0 80 %时 ,其增强效果最好。