悬浮-乳液耦合聚合制备大粒径核-壳结构PS/PMMA复合粒子

采用在苯乙烯(St)悬浮聚合不同时期滴加甲基丙烯酸甲酯(MMA)乳液聚合组分的悬浮-乳液耦合聚合方法,制备大粒径核-壳结构复合粒子。研究发现：在St悬浮聚合初期和宏观成粒基本完成的聚合后期滴加MMA乳液聚合组分,分别得到由初级粒子凝并的非核-壳结构粒子和核-壳结构不完整的复合粒子,粒径分布较宽;在St悬浮聚合中期滴加MMA乳液聚合组分,MMA和PMMA乳胶粒子易于向PS粒子扩散或粘并,制备得到平均粒径大于100gm、粒径分布窄和核-壳结构良好的PS／PMMA复合粒子。     

PBA/MMA-MAA核-壳型乳液聚合研究

本文以种子乳液聚合法制备了PBA／MMA－MAA核－壳型复合取合物乳液。讨论了复合聚合物时引发剂用量和补加乳化剂用量对聚合反应及乳胶粒及其分布的影响。结果表明，引发剂用量控制在0．2％（wt)，乳化剂用量在0．75％（wt)，可制得粒径分布较窄且性能良好的核－壳型聚合物乳液用于毛面剂中。     

n-BMA/MMA共聚核壳乳液的合成研究

通过半连续种子乳液聚合的方法,制备了具有核壳结构的丙烯酸酯聚合物乳胶粒子。采用甲基丙烯酸甲酯(MMA)、甲基丙烯酸酯正丁酯(n-BMA)等单体进行共聚。研究了共聚合过程中,乳化剂浓度、引发剂等对聚合物乳液粒径大小、凝胶量等的影响,并利用动态光散射(DLS)、透射电镜(TEM)和差示扫描量热仪(DSC)对乳胶粒子进行表征。结果表明:核乳液聚合阶段乳化剂浓度增大,乳液粒子的粒径变小,引发剂用量对粒径及分布影响不大;TEM观察到核乳胶粒径大小及变化趋势与DLS测得的结果相一致,并且核乳胶粒子和核壳乳液粒子都呈规则的圆球状,分布均一;DLS测试核壳丙烯酸酯乳胶粒子粒径的变化呈逐渐增长的趋势;DSC测试发现制备的核壳粒子有2个玻璃化转变温度(Tg),验证了胶乳粒子核壳结构的存在。     

中空聚合物微球的制备——溶胀处理条件的影响

采用种子乳液聚合法合成不同核壳比的聚甲基丙烯酸（MAA）-丙烯酸丁酯（BA）一甲基丙烯酸甲酯（MMA）／聚苯乙烯（St）-丙烯腈（AN）核壳乳液,经碱／酸溶胀法处理制备了中空聚合物微球。结果表明,中空聚合物的形态不仅与核壳比有关,也与溶胀处理时碱的种类、温度、溶胀剂及其用量、乳液pH值等因素有关,当核壳比为1：10,溶胀剂用量为核壳乳胶粒质量的1.5倍时,可以得到最大中空度接近30％的中空聚合物微球。     

聚苯乙烯-聚甲基丙烯酸甲酯核-壳粒子的制备及性能

由种子乳液聚合法制备了聚苯乙烯-聚甲基丙烯酸甲酯核-壳粒子。以过硫酸钾（KPS）为引发剂，分别以非离子型辛基酚聚氧乙烯醚（OP—10）和复合十二烷基硫酸钠（SDS）／OP—10（质量比为1：4）为乳化剂，合成了聚苯乙烯种子核。连续滴加甲基丙烯酸甲酯（MMA），以OP—10乳化的种子乳液可以制备粒径范围在0．16～0．67μm的核-壳粒子，当单体苯乙烯与甲基丙烯酸甲酯（St／MMA）的质量比为3：7时，所得粒径为0．18μm，粒径分散系数为0．012。而以OP-10／SDS质量比为4：1制备的种子乳液所得核壳粒子直径在毫米级。差示扫描量热研究显示，以OP-10乳化所得种子乳液制衢的复合粒子的玻璃化转变温度为97．2℃，峰形单一，表现山良好的热性能。     

四元共聚乳液的合成及性能研究

采用异相粒子成核阶段滴加单体乳液的改进种子乳液聚合方法合成了 PBMA／P（BMA－AA－AM）和 PBMA／P（BMA－AA－HMA）2种功能复合聚合物乳液。研究了乳化剂,功能单体对乳液的影响。结果表明：随着乳化剂SLS、OS－15含量的增大,乳液粒径减小,乳液稳定性有一极佳值存在;随着功能单体含量增大,乳液粒径增大。     

亚微米中空微球聚合物的制备及其形貌调控

采用乳液聚合协同碱渗透溶胀法，制备了亚微米中空微球聚合物。通过SEM、TEM、DLS分别对中空微球的形貌和粒径进行表征，并考察了中空微球聚合物的遮盖性能。研究了引发剂用量对核粒径的影响，中间层和壳层聚合物配比对微球形貌结构及其遮盖性能的影响。结果表明，在核制备过程中，核的粒径随引发剂用量的增加而减小；对于平均粒径为148 nm的核，当中间层甲基丙烯酸丁酯（BMA）用量为10 wt%、甲基丙烯酸（MAA）用量为3 wt%，甲基丙烯酸甲酯（MMA）用量为87 wt%，壳层苯乙烯（St）用量为97 wt%，交联剂用量为3 wt%时，可制备平均粒径414 nm，中空率为40.6 %的聚合物微球，且微球表面较为光滑，此时中空微球聚合物具有优异遮盖性能，遮盖度达到66 %。     

蓖麻油聚氨酯-丙烯酸酯复合乳液的合成

采用甲基丙烯酸甲酯（MMA）与蓖麻油水性聚氨酯乳液共聚反应制备聚氨酯丙烯酸酯（PUA）复合乳液,研究了蓖麻油水性聚氨酯性能、MMA添加量、引发剂种类和聚合温度对PUA复合乳液及涂膜性能的影响,并应用傅里叶红外光谱（FTIR）测定反应产物的结构.研究发现,用外观半透明或微透明的PU-M分散液制备的PUA乳液及涂膜性能优良.油溶性引发剂（AIBN）比水溶性引发剂（K₂S₂O₈）更适合本体系的乳液聚合.随着MMA含量增大,PUA复合乳液胶粒粒径增大,黏度减小,涂膜光泽度下降,机械性能变好,耐水性增加.合适的MMA含量为体系总固含量的20%～30%.提出了PUA复合乳液胶粒形成及粒径长大机理.     

胶乳型互穿聚合物网络研究(Ⅱ)─—环氧树脂/聚丙烯酸酯Semi—LIPN的聚合反应

采用氧化还原引发体系及复合乳液聚合方法，研究了环氧树脂／聚（苯乙烯─—丙烯酸丁酯─—甲基丙烯酸甲酯）[EP／P（St─BA─MMA）]半胶乳型工穿聚合物网络（Semi—LIPN）的聚合反应规律。考察了反应温度、引发剂用量、乳化剂用量、交联剂种类及用量，特别是EP含量对单体转化率及反应速率的影响。环氧树脂因含有微量双酚A，在聚合反应中同时起到了阻聚剂和缓聚剂的作用。从而使得该聚合反应较不含合成树脂（或橡胶）的普通乳液聚合要困难得多。     

皮革涂料用丙烯酸酯核-壳乳液的研制

采用种子乳液聚合法，以交联型软性聚合物为核，交联型硬性高聚物为壳，合成了具有优异耐寒性及高温抗回粘性聚合物。讨论了乳化剂种类及应用、核／壳比等对聚合物性能的影响。     

Fabrication and properties of chemically bonded polysilsesquioxane‐polyacrylate/silica hybrid latex films with high silicon content

Polysilsesquioxane‐polyacrylate/silica hybrid latexes (PSQ‐PAS) with high silicon content were prepared by directly mixing colloidal silica with polysilsesquioxane‐polyacrylate emulsion (PSQ‐PA), which was prepared through seeded emulsion polymerization using polymethacryloxypropylsilsesquioxanes as the core and polyacrylate (PA) as the shell respectively. The chemically bonded PSQ‐PAS thin films were obtained via sol‐gel process after addition of hydrophilic cosolvent to PSQ‐PAS emulsion and subsequent drying at room temperature. The effects of silica/PSQ‐PA ratio (w/w) on the film properties of hardness, optical property and thermal stability were investigated. Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS) and transmission electron microscopy (TEM) were used to characterize the chemical composition and morphology of the resultant hybrid particles. DLS and TEM results indicated that both PSQ and PSQ‐PA particles had narrow size distribution and their average diameters were about 200 and 350 nm, respectively. Pendulum durometer, UV–vis spectroscopy, and thermogravimetric analysis (TGA) were used to characterize the hardness, optical property and thermal stability of PSQ‐PAS latex films. The results showed that the PSQ‐PAS films hardness increased with the increasing ratio of silica/PSQ‐PA, whereas the transmittance decreased slightly. TGA curves demonstrated PSQ‐PAS films displayed excellent thermal stability, and the residual silicon weight exceeded 30%. POLYM. COMPOS., 36:389–396, 2015. © 2014 Society of Plastics Engineers     

Film‐formation of polyacrylate/silica composite latexes by sol‐gel process

The polyacrylate/silica composite latexes were prepared by directly mixing silica particles with polyacrylate modified by γ‐methacryloxypropyltrimethoxysilane (MPS). Fourier transform infrared (FTIR) spectra and X‐ray photoelectron spectroscopy (XPS) analysis of polyacrylate/silica composite films confirmed the sol‐gel processes occurred to form Si–O–Si crosslinking bonds during the process of film‐formation. Transmission electron microscope (TEM) images revealed that the polyacrylate latexes were in contact with silica particles while some silica particles stayed together. Atomic force microscope (AFM) photos showed that organic and inorganic phases were strictly connected with each other and silica particles were embedded in the polymeric matrix with a size range of 20–50 nm. Differential scanning calorimetry (DSC) curves demonstrated that the composite film with 3% MPS has higher T_g than those of pure polyacrylate films. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42417.     

乳液法合成纳米SiO_2/聚丙烯酸酯复合材料及其性能研究

以甲基丙烯酸甲酯(MMA)、丙烯酸丁酯(BA)和由四甲氧基硅烷(TMOS)制备的硅溶胶为原料,通过乳液聚合制备了纳米SiO2/聚丙烯酸酯乳液,然后通过溶剂挥发法制得复合材料膜。通过红外光谱(FTIR)、透射电子显微镜(TEM)、力学性能测试和热分析(TG)等手段,对乳液形貌、复合膜材料的组成、力学性能、疏水性能和热性能等方面进行研究。结果表明:纳米SiO2同时起到的增塑和增强作用,对复合物成型后的机械性能和吸水性能有复杂的影响;随着纳米SiO2的加入,复合材料的热稳定性增加。     

Preparation and characterization of waterborne epoxy latexes and epoxy/(silica sol) composites

A series of waterborne epoxy latexes was synthesized, and epoxy/(silica sol) composite latexes were prepared. The effects of functional monomer methacrylic acid (MAA) and silica sol on the latex particle size, morphology, and stability were investigated. With increasing amounts of MAA, the conversion rate increased, the particle size reduced, and the viscosity of the epoxy latexes increased. The epoxy latexes had storage stability and could be stored at room temperature for more than 6 months with a solid content variation of less than 1%. For the (silica sol)‐modified waterborne epoxy latexes, the effects of preparation techniques and silica sol content on the latexes and latex films were investigated. When the silica sol content increased, the particle size of the composite latexes decreased. The morphology investigation showed that when the silica sol content increased, the uneven surface level of the latex films was increased. The increase of elemental silica on the surface was in accord with the improvement of the water resistance of the composite latex films. The heat resistance of these films was improved as well, and their overall performance was better than that of the epoxy latex films. J. VINYL ADDIT. TECHNOL., 20:57–64, 2014. © 2014 Society of Plastics Engineers     

Facile fabrication and modification of polyacrylate/silica nanocomposite latexes prepared by silica sol and silane coupling agent

Polyacrylate/silica nanocomposite latexes were prepared by silica sol and facilely modified with a silane coupling agent γ-methacryloxypropyltrimethoxysilane (KH-570) aimed at reinforcing the interaction between silica nanoparticles and latex particles in a convenient way. The effects of silica sol and KH-570 amounts on the performance of latexes and films are discussed. Particle size and morphology tests demonstrated that the silica nanoparticles could form hydrogen bond interactions between latex particles, and thus influence the rheological properties of latexes. Tensile measurements and SEM photographs showed the reinforcing and toughening roles of silica nanoparticles. SEM images also indicated that the addition of silica sol increased the roughness of films, which resulted in the increase of hydrophilic silanol groups on the film surface and the decrease of water resistance of latex films. The latex films retained good adhesion force, flexibility, and impact resistance even when the silica sol content was as much as 25%. TGA data revealed that the incorporation of silica sol enhanced the thermal stability of the films. After introducing KH-570, the particle size increased with the increase of the amount of KH-570. Moreover, the addition of KH-570 improved the water resistance and maintained other properties of the latex films appropriately.     

纳米SiO_2/聚丙烯酸酯组装杂化乳液的合成及表征

通过乳液聚合法成功合成了纳米SiO2/聚丙烯酸酯杂化乳液。首先将纳米SiO2经过表面官能团化处理,使其表面含有活性官能团,然后经过乳液聚合使丙烯酸酯单体在纳米SiO2表面引发聚合,合成了具有核壳结构的纳米杂化乳液。采用透射电子显微镜(TEM)对乳液的微观结构进行了表征,并对胶膜进行了机械力学性能测试和表面润湿性能测试。结果表明纳米SiO2的表面官能团化处理改善了纳米粒子在乳液中的稳定性,当纳米SiO2质量分数为0 2%时,杂化乳液胶膜的拉伸强度和断裂伸长率同时达到最大值。其表面润湿性与SiO2质量分数有关,SiO2质量分数为0 5%时其杂化乳胶膜的接触角最大,耐水性最好。     

Preparation and characterization of silica sol/fluoroacrylate core–shell nanocomposite emulsion

The silica sol/fluoroacrylate core?Cshell nanocomposite emulsion was successfully synthesized via traditional emulsion polymerization through grafting of KH-570 onto silica particles. Comparing the performance of the polyacrylate copolymer, the fluorinated polyacrylate copolymer and the silica sol/fluoroacrylate core?Cshell nanocomposite emulsion, we can come to a conclusion that the silica sol/fluoroacrylate core?Cshell nanocomposite emulsion presents significantly excellent performance in all aspects. The products were characterized by Fourier transform infrared (FTIR), photon correlation spectroscopy (PCS), transmission electron microscopy (TEM), thermogravimetry (TGA), Contact angle and UV?Cvis analyses techniques. The chemical structure of polyacrylate copolymer, fluorinated polyacrylate copolymer and silica sol/fluoroacrylate nanocomposite were detected by FTIR. The size and stability of emulsion latex particles were determined by PCS technique. TEM analysis confirmed that the resultant latex particle has the core?Cshell structure, obviously. The water absorption and contact angle data also showed that the silica sol/fluoroacrylate nanocomposite film has good hydrophobic performance. TGA analysis indicated the weight loss of the silica sol/fluoroacrylate nanocomposite film begins at around 350?°C which testifies its good thermal stability. The UV?Cvis spectroscopy analysis showed that the silica sol/fluoroacrylate nanocomposite film possess UV?Cvis shielding effect when the added volume amount of KH570 modified silica sol is up to 5?mL. Therefore, the excellent properties of hydrophobicity, thermodynamics and resistance to ultraviolet provide the silica sol/fluoroacrylate nanocomposite film with potential applications in variety fields. In addition, the formation mechanism of core?Cshell structure silica sol/fluoroacrylate nanocomposite latex particles was speculated.     

Synthesis and characterization of nanosilica/polyacrylate composite latex

The nanosilica/polyacrylate organic–inorganic composite latex was synthesized by in‐situ emulsion polymerization of methyl methacrylate (MMA) and butyl acrylate (BA) in the presence of silica nanoparticles, which were modified by silane coupling agent. The surface properties and dispersibility of silica nanoparticles modification, chemical structure, Zeta potential, diameter distribution of the composite latex prepared, surface roughness, and thermal stability of the hybrid film formed by the composite latex were investigated by fourier transform infrared spectrometer (FTIR), transmission electron microscopy (TEM), Zeta meter, ZetaPlus apparatus (dynamic light scattering method), atomic force microscopy (AFM), and thermogravimetric analysis (TGA), respectively. After modification with silane coupling agent, silane was grafted onto the surface of silica nanoparticles to form the organic layers, which was able to efficiently prevent the silica nanoparticles from aggregating to individually homogeneous disperse in the in‐situ emulsion polymerization system and improve the compatibility of silica nanoparticles with the acrylate monomers. The nanosilica/polyacrylate organic–inorganic composite latex prepared had the properties of silica nanoparticles and pure polyacrylate latex but was not simply a combination. Strong chemical bonding tethered the silica and acrylate chains to form the core/shell structural composite latex. Consequently, the hybrid film formed by nanosilica/polyacrylate composite latex exhibited a smooth surface and better thermal properties than the pure polyacrylate film. POLYM. COMPOS. 27:282–288, 2006. © 2006 Society of Plastics Engineers     

自交联封闭性乳液的合成与性能

以双丙酮丙烯酰胺（DAAM）、甲基丙烯酸甲酯（MMA）、丙烯酸丁酯（BA）和甲基丙烯酸（MAA）为共聚单体,采用半连续种子乳液聚合工艺合成自交联封闭性聚丙烯酸酯乳液（PAE）,考察了DAAM和复合乳化剂对乳液聚合稳定性以及涂膜性能的影响。研究发现：随着DAAM含量的增加,乳液聚合稳定性下降,粒径增大,涂膜的耐介质性能和交联度提高,合适的DAAM加入量为总单体质量的3.0%,DAAM和己二酰肼(ADH)的最佳摩尔比为2∶1。采用SDBS+OP-10+OP-40为复合乳化剂体系,选用乳化剂的含量为2.35%,阴/非离子乳化剂质量比为1∶1.25;复合乳化剂在种子、核、壳比例为1.5∶1∶2,制备的乳液具有较好的聚合稳定性（乳液凝胶率低和单体转化率高）,乳液耐电解质（钙离子）稳定性好,涂膜具有优异的封闭性。傅里叶红外光谱（FTIR）表明在涂膜形成过程中DAAM的酮羰基与ADH的酰肼基反应生成腙（C=N）,TEM分析显示乳液的乳胶粒子呈核壳结构,TGA分析发现DAAM改性的PAE降低了涂膜的热稳定性。     

汽车底盘涂料用核壳结构聚丙烯酸酯乳液的制备与性能研究

采用乳液聚合制备了一系列核壳结构丙烯酸类聚合物,通过分子结构设计,改变核层与壳层的单体组成,考察其对聚合物综合性能的影响,以及非极性增塑剂DOP和极性增塑剂TCP对其溶胶和凝胶性能的影响。研究结果表明：选用玻璃化温度较高的Pi—BMA作为聚合物的核层,MMA／MAA共聚物作为壳层,其溶胶和凝胶性能明显优于其它核壳聚合物,该核壳聚合物在汽车工业中具有广阔的应用前景。