P(PVE-CTFE-SUA)三元无皂乳液的制备及性能研究

通过无皂乳液聚合制得聚(乙烯基正丙基醚-三氟氯乙烯-十一烯酸钠)[P(PVE-CTFE-SUA)]三元无皂乳液,考察了SUA用量对乳液稳定性、乳胶粒的粒径及接触角的影响,分析了PVE和CTFE的比例与聚合物结构及性能的关系,同时测试了乳胶粒的形貌。结果表明：无皂乳液聚合可以制得稳定性好、粒径分布均匀的含氟乳液,SUA对乳液的稳定性和表面性能影响较大;PVE和CTFE的比例影响聚合物的结构和性能,在一定条件下聚合物为交替共聚物。     

P(CTFE-BVE-SUA)含氟无皂乳液的制备

以无皂乳液聚合法合成了聚(三氟氯乙烯-乙烯基正丁基醚-十一烯酸钠)[P(CTFE-BVE-SUA)]含氟共聚物乳液,考察了单体配比对聚合反应的影响,同时对影响乳液粒径的因素进行了研究。结果表明:以无皂乳液聚合法制得的含氟乳液稳定性好、粒径分布均匀。通过控制单体配比可以得到不同结构、不同氟含量的乳液。聚合反应中过硫酸钾(KPS)的浓度、聚合温度以及SUA用量对乳液粒径的影响较大,试验中还发现,聚合反应过程中压力的变化与反应的进程是同步的。     

无皂乳液聚合制备AANa-VAc-TFEMA纳米含氟乳液

以丙烯酸钠(AANa)、乙酸乙烯酯(VAc)和甲基丙烯酸三氟乙酯(TFEMA)为单体进行无皂乳液聚合,合成了P(AANa-VAc-TFEMA)纳米含氟乳液,考察了反应温度、引发剂用量、单体配比对聚合的影响,并着重对聚合物乳液的粒径进行了研究。结果表明:该聚合单体的转化率可达到97.00%以上,聚合得到的无皂乳液稳定性好、粒径分布均匀。通过控制单体配比中AANa的含量及VAc与TFEMA的比例,可以得到纳米含氟乳液。     

P(BVE-CTFE-MAH)三元共聚物的结构和自乳化乳液研究

对乙烯基正丁基醚(BVE)-三氟氯乙烯(CTFE)-马来酸酐(MAH)三元共聚物进行了研究。考察了单体配比对聚合物结构及形貌的影响;研究了聚合物表面的元素含量;并对共聚物自乳化乳液进行了分析。结果表明:通过控制单体配比,可以获得不同结构、不同形貌的含氟聚合物;聚合物中MAH单元的比例对P(BVE-CTFE-MAH)共聚物的形貌影响较大,当MAH的加入量超过3份时,产物为蓬松白色固体粉末;P(BVE-CTFE-MAH)共聚物可形成自乳化乳液,乳胶粒的粒径随着聚合物中MAH比例的增大而变小。     

P(CTFE-BVE-TGME-SUA)无皂乳液的制备与性能

以无皂乳液聚合法合成得到聚(三氟氯乙烯/乙烯基正丁基醚/羟丁基乙烯基醚/十一烯酸钠)P(CTFE-BVE-TGME-SUA)乳液,考察了SUA及TGME的用量对乳液稳定性及粒径大小的影响,并研究了聚合物膜的表面性能。结果表明:P(CTFE-BVE-TGME-SUA)乳液稳定性好,粒径分布均匀;P(CTFE-BVE-SUA)聚合物乳液中SUA对乳液的稳定性和粒径大小影响较大;P(CTFE-BVE-TGME-SUA)聚合物乳液中TGME对乳液的稳定性和粒径大小影响较大;P(CTFE-BVE-TGME-SUA)聚合物膜的表面性能随着TGME含量的增加而下降。增加聚合物乳液中TGME的含量P(CTFE-BVE-TGME-SUA)聚合物膜对溶剂的接触角变小,表面能提高。     

醋酸乙烯-丙烯酸无皂乳液共聚的研究

研究了醋酸乙烯(VAc)与丙烯酸(AA)以“半连续”加料方式进行无皂乳液共聚合。探讨了功能单体AA用量、反应温度等对共聚的影响。采用FTIR、粒度分析等测试方法对共聚物的组成、乳胶粒子的粒径及分布进行了分析表征。结果表明,在(65±2)℃的温度下聚合,所得乳液稳定性好、转化率高,反应完全,且随着功能单体AA用量的增加,乳液黏度上升,单体转化率下降,乳胶粒粒径变小且粒径单分散性好。     

含氟丙烯酸酯共聚物无皂乳液的粒子形态与性能研究

研究了通过半连续滴加法制备的无皂含氟丙烯酸酯聚合物乳液乳胶粒形态、聚合条件对乳胶粒粒径的影响,测定了乳液性能和乳胶膜的表面性能。制备的含氟乳液的乳胶粒呈圆形,粒径分布窄。乳液稳定性好,含氟乳胶膜对水的接触角为110.2°,吸水率低,表现出优异的表面性能。     

α-甲基苯乙烯和苯乙烯共聚物乳液的合成及性能研究

在不通N2的条件下,采用半连续法,在85℃、乳化剂用量为总量的7.53%时合成出了不同单体配比的α-甲基苯乙烯-苯乙烯共聚物[P(AMS-St)]乳液,其中AMS单体含量最高可达70%以上。用红外、核磁对共聚物结构进行了表征,讨论了加料方式、反应温度、乳化剂用量、单体配比对乳液转化率及稳定性的影响和单体组成与乳液流变性、乳胶粒径大小之间的关系。结果表明随单体中AMS含量的增加,乳液黏度逐渐变大,乳胶粒径逐渐变小,乳胶粒具有均一的尺寸。     

阳离子型含氟聚丙烯酸酯无皂乳液的合成及性能

以可逆加成断裂链转移(RAFT)聚合合成的聚甲基丙烯酸-N,N-二甲氨基乙酯-b-聚丙烯酸六氟丁酯(PDMAEMA-b-PHFBA)为稳定剂,通过无皂乳液聚合技术合成了阳离子型含氟聚丙烯酸酯无皂乳液。用FTIR、1HNMR、TEM、DLS对乳胶粒子和聚合物的结构进行了表征。结果表明,当PDMAEMA-b-PHFBA的用量为总加料质量的2.4%时,乳液的稳定性好,Zeta电位达+57.8 m V,转化率达97.6%,乳胶粒具有明显的核壳结构,粒径分布指数为0.058。将阳离子型含氟聚丙烯酸酯无皂乳液用于皮革涂饰后,随着丙烯酸六氟丁酯用量的增加,涂饰后的皮革对水和二碘甲烷的接触角逐渐增加,当丙烯酸六氟丁酯用量为总单体质量的10%时,涂饰后的皮革对水的接触角为125°,对二碘甲烷的接触角为81.5°。     

醋酸乙烯-丙烯酸无皂乳液共聚的研究

研究了以醋酸乙烯(VAc)为主单体,丙烯酸(AA)为改性功能单体,以“半连续”加料方式进行无皂乳液共聚合过程,得到了稳定的乳液。并探讨了功能单体AA含量、反应温度等对共聚的影响。采用FTIR、粒度分析等方法对共聚物的组成、乳胶粒子的尺寸及分布进行了分析表征。结果表明:在(65±2)℃的温度下聚合,所得乳液稳定性好、转化率高,反应完全,且随着功能单体AA含量的增加,乳液粘度上升,单体转化率下降,乳胶粒粒径变小且粒径呈单分散性。     

甲基丙烯酸三氟乙酯/十一烯酸钠无皂乳液的制备与性能研究

对甲基丙烯酸三氟乙酯/十一烯酸钠（TFEMA/SU）无皂乳液聚合体系进行了研究。考察了单体配比对聚合反应及乳液性质的影响,研究了SU的用量对乳液稳定性、黏度、乳胶粒粒径大小及分布等的影响。实验发现：以TFEMA和SU为单体可制得稳定性较好的无皂乳液,SU的用量是影响乳液稳定性、乳液黏度及乳胶粒粒径大小的关键因素。配方中SU的质量分数控制在3%～9%,制得的乳液稳定性较好,低于或高于此添加量,稳定性较差;当SU的质量分数由3%增大到9%时,乳液的电解质稳定性由1.6 mL增大到2.2 mL,黏度由102 mPa.s增大到379 mPa.s,说明SU量的增大对乳液的电解质稳定性及黏度提高是有利的。     

N-苯基马来酰亚胺与苯乙烯共聚物乳液的研究

采用种子乳液聚合法制备了N-苯基马来酰亚胺(NPMI)与苯乙烯(St)共聚物乳液,讨论了单体配比对共聚物乳液的聚合稳定性、转化率、流变性、表面张力、粒径大小及分布的影响。结果表明:随着混合单体中NPMI含量的增加,NPMI与St混合单体的转化率降低,聚合物乳液的凝胶量增大,聚合稳定性减弱,黏度逐渐增加。所得共聚物乳液粒径为70~80nm,粒径分布均匀。     

核壳结构聚硅氧烷/丙烯酸酯复合乳液(Ⅰ)乳化剂对乳液聚合过程及粒径分布和粒子形态的影响

采用种子乳液半连续法合成了具有高有机硅含量的聚硅氧烷/丙烯酸酯核壳结构复合乳液,研究乳化剂的种类、复配比例及质量浓度对有机硅／丙烯酸酯壳核乳液性能与乳胶粒径、分布和结构的影响.结果表明：阴离子乳化剂十二烷基硫酸钠(SDS)、十二烷基磺酸钠(SDS-2)、十二烷基苯磺酸钠(SDBS)所合成的乳胶粒子粒径依次增大,SDS与非离子型乳化剂OP-10复配使用时,随OP-10质量分数的增加,聚合速率和转化率降低,化学稳定性增加,乳胶粒子粒径增大,分布变宽,确定了复合乳化剂的最佳配比.随复合乳化剂浓度的增加,聚合速率加快、转化率增加,乳胶粒子粒径减小而分布加宽.通过改变乳化剂加入方式可减小乳胶粒子的粒径分布.为减少壳层聚合物新粒子的产生,需严格控制乳化剂的浓度,使加入的壳层单体处于“饥饿”状态,在乳胶粒子表面富集、引发聚合,形成表层“过渡层”,最终形成核壳结构复合粒子.     

Semi-continuous emulsion copolymerization of vinyl acetate and butyl acrylate in presence of AMPS

The emulsifier-free emulsion polymerization of vinyl acetate (VAc) and butyl acrylate (BA) in the presence of 2-acrylamido-2-methylpropane sulfonic acid (AMPS) was carried out by a semi-continuous process. AMPS was a reactive surfactant in the aqueous emulsion, due to its amphiphilic structure and the unsaturated double bonds. Potassium persulfate (KPS) was used as initiator. The following factors were mainly examined: quantity of AMPS, BA and KPS concentrations, which could significantly affect the particle size and its distribution, conversion, gel content, minimum film-forming temperature, etc. The particle size and its distribution were characterized by dynamic laser particle size analyzer, and morphology of the latex particles was characterized by transmission electron microscopy (TEM). Fourier transform infrared spectroscopy was used to characterize chemical structure of copolymers. The results indicated that AMPS was successfully reacted onto the resulted copolymer of vinyl acetate and butyl acrylate. A hydrophilic sulfonic acid group in the molecular structure of AMPS tended to be distributed in particles surface after polymerization. As a result, an electrostatic repulsion between the particles was produced in order to maintain stability of the system. Thermogravimetric analysis curves suggested that as BA content increased, thermal stability of the polymer increased accordingly. The conversion-time plots with varying AMPS and initiator contents were obtained, which illustrated that the initiator concentration could greatly influence the polymerization rate and the final conversion. The TEM micrographs of the final emulsifier-free latex particles for P(VAc/BA/AMPS) system revealed small particle size in monodisperse polymer latex. The particles of the latex were measured as about 150 nm.     

核壳纯丙乳液的结构形态对Tg及MFT影响的研究

研究了核壳纯丙乳液聚合中乳液结构对其玻璃化转变温度、最低成膜温度的影响，以及单体种类、核壳比、核壳设计Tg对乳液性能的影响，还通过TEM、AFM研究了乳液颗粒形态及核壳乳液成膜后的表面形态。     

无皂苯丙乳液的合成及其性能研究

在少量甲基丙烯酸钠盐的存在下，成功合成了具有高稳定性、高透明性的聚（苯乙烯／丙烯酸丁酯）P（St/BA)无皂共聚乳液。同时，还对不同配方的乳液及其涂膜的综合性能进行了研究，总结了组成与性能之间的对应关系，并着重讨论了单体组成与乳液表面能、乳胶粒尺寸之间的关系。结果表明：随单体配比中St含量的增加，乳液接触角和乳胶粒粒径减小；乳胶粒具有均一的尺寸，并显示出明显的核壳结构。通过对苯丙无皂乳液组成与性能关系的研究，积累了一定量的理论数据，为无皂乳液产品的进一步研究开发提供了条件。     

Preparation and Properties of Siloxane-Modified Styrene-Acrylate Latex Particles with Core-Shell Structure

Siloxane-modified styrene-acrylate latex particles with core-shell structure were prepared by two-stage semicontinuous emulsion polymerization using a reactive surfactant. Effects of catalyst dosage, weight ratio of γ-methacryloxypropyltrimethoxysilane (MAPS) to hydroxyl silicone oil (HSO) and siloxane content on the grafting degree of siloxane were studied. The chemical components of the copolymer were characterized by Fourier transform infrared spectra. The micromorphology of latex particles was observed by transmission electron microscopy. The stability properties of emulsion were tested by Ca²⁺, centrifugal, and mechanical stability test. The latex film was studied by water contact angle, water absorption ratio and thermal gravimetric analysis. The results show that siloxane-modified styrene-acrylate latex with core-shell structure can be synthesized using reactive surfactant and the prepared emulsion presents excellent stability. By using hydroxyl silicone oil (HSO) to react with silane coupling agent MAPS during emulsion polymerization, HSO can be located in the side chain of the polymer and endow the latex film with excellent stabilities.     

STUDIES ON SYNTHESIS OF SILICA SOL-ORGANIC POLYMER COMPOSITE EMULSION

An emulsion of polystyrene/poly (butylacrylate-methyl methacrylate acrylic acid) core/shell latex particles (PS/P (BA-MMA-AA)) has been prepared by use of three synthetic methods. The effects of synthetic methods on the distribution of carboxyl groups in latex particles were studied. The results show that the seed emulsion polymerization in which the pre-emulsified monomers were added by dropping method to the second stage is the best technique for obtaining the optimum distribution of carboxyl groups on the surface of the latex particles. Furthermore, by using PS/P (BA-MMA-AA), a type of novel composite emulsion of silica sol-PS/P (BA-MMA-AA) was synthesized with the above method. By observation through transmission EM, the morphology of the latex particles obtained shows that a composite structure has been formed between silica sol particles and organic polymer particles.     

Polymerization of MMA at the surface of inorganic submicron particles

Inorganic submicron particles, such as TiO₂, were modified with titanate coupling agents. The structure and stability of some titanates, both in solution and at the particle surface, were investigated by various methods. The modified titanium dioxide was dispersed in a solution of sodium dodecylsulphate (SDS) in water. The surfactant adsorbs at the now hydrophobic particle surface, thus creating a micellelike structure with an inorganic particle in the centre. In this system an emulsion polymerization of methyl methacrylate was carried out. Product formed at the particle surface is either physically bound by entanglement or chemically bound by covalent bonding to the titanates. In this way a core-shell morphology is obtained with an inorganic core and a polymer shell. The effects of several reaction parameters on the kinetics of the polymerization were studied. The encapsulated TiO₂ particles may offer interesting prospects in those applications where good coupling between polymer matrix and inorganic particles is necessary, such as latex paints and polymer composite materials.