无皂乳液聚合合成单分散纯丙乳液

研究了甲基丙烯酸甲酯、丙烯酸丁酯、甲基丙烯酸、丙烯酸羟乙酯的无皂乳液聚合,考察了单体浓度、引发剂用量、温度、单体配比等对无皂乳液聚合的影响,得到了单分散高固含量的纯丙乳液。     

醋丙乳液的研制

介绍了丙烯酸酯改性聚醋酸乙烯酯乳液的合成方法,利用种子乳液聚合合成了一种高性能醋酸乙烯-丙烯酸丁酯共聚乳液,确定了最佳的聚合配方和聚合工艺,经实验测试,乳液性能良好,尤其是乳液的耐水性和耐寒性得到改善。     

Seeded emulsion polymerization of styrene: Incorporation of acrylic acid in latex products

Seeded batch emulsion polymerization of styrene and acrylic acid was studied. The influence of pH and acrylic acid content on the polymerization rate and the amount of carboxylic acid groups incorporated in the final latex products was investigated. The distribution of the functional groups over the aqueous phase, the latex particle surface, and the interior of the latex particle was determined using aqueous conductometric titration and nonaqueous potentiometric titration at intermediate and complete overall conversions. Combined with kinetic results, the carboxylic acid group distribution history provided valuable information about the process of incorporation of acrylic acid in latex products. Two‐step processes in which a shot of acrylic acid was performed in the last stage of the emulsion polymerization reaction were investigated as a strategy to increase the surface incorporation efficiency. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 875–885, 2000     

氧化还原引发聚合丙烯酸酯乳液及胶粘剂的研究

主要探讨了氧化还原引发剂用量对聚合反应速度、单体转化率的影响。同时对乳化剂用量,湿润剂种类用量,增粘乳液对乳液胶粘剂的性能的影响也进行了分析。研究发现:适宜的氧化还原引发体系的用量在单体的0．3％-0．8％之间;复合乳化剂用量为总量的2％-4％之间;LSR-101湿润剂为单体总量的0．5％-1．7％;增粘乳液用星为25％时,可得到转化率高,粘接性能良好的胶粘剂。     

高羟基含氟丙烯酸乳液的合成及性能研究

以丙烯酸酯类单体作为原料,以过硫酸钾为引发剂,采用预乳化半连续乳液聚合方式合成了高羟基丙烯酸乳液,并在后期补加氧化还原体系引发剂,提高了单体的转化速率。系统地研究了乳化剂用量、羟基单体、氟单体、硅单体含量等因素对涂膜性能的影响。最后,将制备的丙烯酸羟基组分同水性固化剂配制成双组分水性丙烯酸聚氨酯清漆,并分析清漆的性能。     

核/壳型ACR乳液的聚合研究

采用预乳化工艺，种子聚合法，通过甲基丙烯酸甲酯(MMA)说明丙烯酸丁酯(BA)接枝共聚反应，制得具有核／壳结构的丙烯酸酯类抗冲击改性剂(ACR)乳液，讨论了乳化、剂用量、引发剂用量、交联剂用量及反应温度对乳液聚合和PVC性能的影响。     

用乳液法合成丙烯酸丁酯-甲基丙烯酸共聚胶乳

采用乳液聚合法合成了丙烯酸丁酯和甲基丙烯酸共聚胶乳,用红外光谱对胶乳的结构进行了表征,讨论了加料方式、水油体积比和引发剂与胶乳性能的关系。结果表明,聚合中分3次加料可使反应更平稳地进行;控制水油体积比在1.50左右更易于反应的控制,胶乳性能也较好;引发剂质量分数为0.2%~0.4%时反应体系稳定,胶乳中的单体残留量少,共聚胶乳的性能较好。     

Adhesion enhancement in waterborne acrylic latex binders synthesized with phosphate methacrylate monomers

The effect of the addition of a phosphoric acid group containing monomer on polymerization kinetics, copolymer microstructure and end-use properties of a latex prepared by seeded emulsion polymerization of MMA/BA/MAA/AAEMA/SIPOMER PAM100 was studied. It was found that despite of the surface activity of the phosphated monomer, the polymerization kinetics was not affected. Gel content increased with the concentration of phosphate monomer due mainly to the presence of divinyl ester phospate impurities. Gel improved the chemical resistance of the latex films. However, the most affected property was adhesion. Increasing amounts of the phosphated monomer led to a strong enhancement of the adhesion due to chemical interactions established with the metal surface. It was also found that the feeding strategy of the phosphated monomer played an important role in the adhesion enhancement. Latexes synthesized using a delayed addition of the phosphate monomer showed better performance than latexes prepared following a conventional addition strategy. The latexes synthesized during the investigation were evaluated as binders in a primer formulation. A primer with good adhesive and corrosion resistance properties was achieved using a 5 wt.% of the phosphated monomer.     

Superparamagnetic latex synthesized by a new route of emulsifier‐free emulsion polymerization

The aim of this study was to design polymeric nanospheres containing magnetic nanoparticle which could display superparamagnetic behavior and thus find application in allied fields. First magnetite nanoparticles were synthesized with coprecipitation method and then their stable acidic dispersion was prepared without surfactant and dropped into the polymerization system during a certain time interval after the polymerization started. The effects of time at which the magnetic sol was added into polymerization system on latex size and stability, average molecular weight of polymer were examined in the case of two different monomer concentrations. Extensive characterization by transmission electron microscopy, dynamic light scattering, thermal gravimetric analysis and magnetic measurements shows that when the magnetic sol was dropped during earlier time of polymerization at stage 1, the latex size, average molecular weight of polymer, thermal stability of polymeric composite, and saturation magnetization reduced, whereas polydispersity of size and molecular weight increased because of the reaction between persulfate and naked surface of magnetite at the aqueous phase. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

聚醋酸乙烯酯乳液胶粘剂的改性研究

介绍了醋酸乙烯酯-丙烯酸酯多元共聚乳液的合成工艺,讨论了单体组成、乳化剂组成、反应温度等对乳液性能的影响。     

Preparation and characterization of novel self cross‐linking fluorinated acrylic latex

Self crosslinking fluorinated acrylic latex (SCLFAL) has been successfully prepared via starved seeded semibatch emulsion polymerization of butyl acrylate (BA), methyl methacrylate (MMA), 2‐(perfluoro‐(1,1‐bisisopropyl)‐2‐propenyl)oxyethyl methacrylate (POMA), and N‐methylolacrylamide (NMA). The resultant SCLFAL is characterized by Fourier transform infrared (FTIR) spectrometry and nuclear magnetic resonance (NMR). Influences of the added amount of NMA on the crosslinking degree, contact angle, particle size, and glass transition temperature (T_g) of the film are investigated. Results show that the crosslinking degree, contact angle, and T_g of the film can be improved when the moderate amount of NMA is introduced into the mixed monomers. However, the added amount of NMA has no marked effect on the particle size of SCLFAL. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

细乳液聚合制备有机硅/丙烯酸酯乳液及其性能

利用细乳液聚合技术设计并制备了不同有机硅含量的有机硅改性丙烯酸酯共聚物稳定乳液.通过细乳液共聚合反应在丙烯酸酯类聚合物主链上引入硅氧烷侧基,该基团水解后与羟基硅油缩合,引入聚硅氧烷接枝链.研究表明：（1）γ-甲基丙烯酰氧丙基三甲氧基硅烷(MPMS)比乙烯基三乙氧基硅烷(VTES)更适合在本体系中用作共聚有机硅单体;（2）聚合过程中,乳液稳定,凝聚物很少;（3）羟基硅油能较好地接枝到丙烯酸酯聚合物主链上,接枝率在50%左右;（4）有机硅的引入减少聚合物涂层的吸水率,表面的水接触角也明显增大,显示出较强的疏水特性.有机硅含量在10%（质量）时,聚合物涂层即可显示很好的憎水特性,随着有机硅含量进一步提高,憎水特性可进一步提高,聚合物涂膜吸水率可低至5%,水接触角可高达105°.     

自增稠多元丙烯酸酯共聚乳液的合成

以丙烯酸、丙烯酸酯以及N-羟甲基丙烯酰胺为原料,OP-10和K12为复合乳化剂,用半连续乳液聚 合工艺合成了自增稠多元丙烯酸酯共聚乳液。研究了引发剂用量、乳化剂用量以及聚合温度等因素对丙烯酸 酯共聚乳液性能的影响。     

有机硅改性丙烯酸酯微乳液的合成研究

以八甲基环四硅氧烷(D4)、-γ甲基丙烯酰氧基丙基三乙氧基硅烷(KH570)和六甲基二硅氧烷(MM)为原料,在Me4NOH催化和二甲基亚砜(DMSO)促进作用下,通过本体聚合合成了侧链含双键的有机硅大分子,可用红外光谱图测定分子结构。采用微乳液聚合法,将丙烯酸酯单体、有机硅大分子单体进行自由基聚合,制备有机硅改性丙烯酸酯微乳液。利用5因素4水平正交实验优化出最佳工艺参数:乳化剂用量为3%,有机硅大分子的用量为9%,单体配比为0.76,异丙醇用量为1.5%,可获得高稳定性乳液,成膜各项性能提高。     

有机硅改性聚醋酸乙烯乳液胶粘剂的研究

合成了有机硅改性聚醋酸乙烯乳液胶粘剂 ,讨论了有机硅与不饱和酸酐对乳液胶粘剂粘接性能的影响。结果表明 :该改性乳液具有良好的粘接强度、耐低温性能和耐水性。     

Seeded emulsion polymerization of styrene: influence of acrylic acid on the particle growth process

The seeded batch emulsion copolymerization of styrene and acrylic acid was studied. The polymerization rate was investigated with pH as the main parameter. Some attempts were made to evaluate the average number of growing chains per particle during Stage II of the emulsion polymerization process. The final latex products were characterized by means of conductometric aqueous titration and potentiometric titration in an organic solvent mixture. The distribution of the acid groups over the aqueous phase, the particle surface, and the interior of the particles together with the kinetic results provided insight into important features governing the incorporation of acrylic acid. The results indicate that pH is the dominating parameter for the incorporation process. An optimal incorporation on the surface of the particles is observed for a low value of pH. In that case, all the acid groups are protonated. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 1186–1196, 2000     

胃溶型丙烯酸树脂乳液的制备

采用乳液聚合法,以甲基丙烯酸甲酯(MMA)和甲基丙烯酸二甲氨基乙酯(DM)为单体,制备了可直接用于药物包衣的胃溶型丙烯酸树脂乳液。结果表明,当温度为65℃,单体摩尔比为1∶1,引发剂和乳化剂用量分别为0.6%和0.3%,采用单体连续滴加法时,可制得稳定的乳液,聚合物分子量为14.9万。在180℃以下,产品的失重率基本不随温度而变,而在180℃以上,失重率随温度升高而增加。聚合物膜在缓冲溶液中的失重率随pH的增加而减小,当pH为1.0和2.0时,膜几乎全部溶解,pH为3.0时,膜的失重率为65.0%,在pH为4.0时,失重率迅速降低到32.8%,到pH为7.0时,膜已基本不溶。     

聚合工艺对丙烯酸酯乳液胶粘剂性能的影响

主要研究了聚合工艺对丙烯酸酯乳液胶粘剂性能的影响 通过对乳液胶粘剂的各种性能测试,发现3种聚合方法中,种子乳液聚合法制备的乳液胶粘剂的综合性能较为理想 采用种子乳液聚合法,最佳聚合工艺为:单体的滴加时间4h、聚合温度50℃、搅拌速率80 r/min     

室温可自成膜中空微粒乳液的制备

采用羧基单体进行多阶段的种子乳液聚合,制备了内核为带羧基的聚合物、最外层为易成膜的低玻璃化温度聚合物、中间为轻度交联中间隔离层的多层核壳结构乳胶粒,最后通过碱处理制成了具有室温成膜性的中空结构聚合物微粒。研究表明,在反应前期以十二烷基苯磺酸钠为乳化剂,包壳阶段同时加入OP-10可有效控制乳胶粒结构形态,同时提高聚合物乳液的电解质稳定性;以甲基丙烯酸为羧基单体,其用量为核单体总量的30%(质量分数)时,聚合物微粒中空直径较大且微粒结构规整;碱处理温度以100℃为宜。在优化的工艺下,制得的室温可成膜中空聚合物微粒外径约500 nm,中空直径约300 nm。     

无皂乳液聚合法制备丙烯酸改性聚醋酸乙烯酯乳液的研究

以丙烯酸(AA)为改性单体,过硫酸铵(APS)为引发剂,采用无皂乳液聚合法制备了AA改性PVAc(聚醋酸乙烯酯)乳液。着重探讨了AA和APS含量对乳液凝胶率、转化率、固含量、粒径分布以及耐水性等影响。研究结果表明:该乳液是由3种单体共聚而成的;当w(AA)=20%、w(APS)=0.5%(均相对于混合单体总质量而言)时,聚合反应转化率(为82.5%)相对最大、凝胶率(为0.81%)相对最小、乳液平均粒径为2.17μm且粒径分布较窄,胶膜的耐水性较佳(吸水率仅为17.35%)。