高耐水白性水包水多彩涂料连续相用硅丙乳液的制备

以γ-甲基丙烯酰氧基丙基三甲氧基硅烷(AC-63)、γ-甲基丙烯酰氧基丙基三乙氧基硅烷(AC-636)、γ-甲基丙烯酰氧基丙基三异丙氧基硅烷(AC-638)为功能单体,甲基丙烯酸甲酯(MMA)、甲基丙烯酸(MAA)、丙烯酸丁酯(BA)、丙烯酸异辛酯(2-EHA)为原料,通过半连续乳液聚合法制备了自交联型有机硅改性丙烯酸酯乳液,研究了有机硅单体种类、加入方式及用量和MAA用量等对乳胶膜耐水白性能的影响。结果表明:当MAA用量占单体总量的1%时,采用AC-638为改性单体制备硅丙乳液,乳液聚合过程稳定,凝胶量少;当其用量为3%且采用后加入方式时能很好地解决乳胶膜的耐水白问题。用此硅丙乳液制备的水包水多彩涂料具有较好的稳定性和耐水白性。     

阳离子型聚甲基丙烯酰氧丙基三(三甲基硅氧基)硅烷乳液的制备及应用研究

以γ-甲基丙烯酰氧丙基三(三甲基硅氧基)硅烷(TRIS)为原料、十八烷基聚醚丙烯酸酯三甲基氯化铵和烷基酚聚氧乙烯基醚为复合乳化体系、2,2'-偶氮二异丁基脒二盐酸盐为引发剂,采用预乳化乳液聚合反应,制备了阳离子型聚甲基丙烯酰氧丙基三(三甲基硅氧基)硅烷(PTRIS)乳液。探讨了预乳化方法对单体预乳化液粒径和稳定性的影响;采用正交实验考察了引发剂用量、乳化剂用量、反应温度、反应时间对乳液性能的影响;采用红外光谱对聚合物结构进行表征,并研究其表面性能。结果表明,采用机械搅拌辅助超声均质的方法能获得粒径为229.4 nm、放置30天不分层的单体预乳化液;其乳液聚合反应的最佳条件为:引发剂用量为单体质量的0.75%、乳化剂用量为单体质量的3%、反应温度为75℃、反应时间为4 h,在此条件下制得的PTRIS乳液外观均匀、单体转化率达到94.8%、无凝胶生成、平均粒径357.5 nm、多分散系数0.145、Zeta电位20.2 m V、稳定性良好;经阳离子型PTRIS乳液整理的棉布对水的接触角达135°,对二碘甲烷的接触角达117°,表面能为3.82 m N/m,具有优异的疏水疏油性能。     

硅烷改性丙烯酸酯乳液性能研究

在水解抑制剂(YZ-1)的作用下,通过乳液聚合实现甲基丙烯酸甲酯(MMA),丙烯酸丁酯(BA)和γ-甲基丙烯酰氧基丙基三甲氧基硅烷(KH570)共聚,合成了硅丙乳液。研究了YZ-1和KH570用量对聚合过程和聚合物性能的影响。结果显示,当YZ-1用量2%,硅单体质量分数9%时,聚合过程稳定,共聚物具有较好的相容性,乳胶膜的吸水性由8.33%降至2.64%。     

用界面氧化还原引发双原位细乳液法制备树莓状纳米复合微球(英文)

以苯乙烯、对苯二乙烯、正硅酸乙酯、正十六烷及γ-甲基丙烯酰氧基丙基三甲氧基硅烷为原料,采用双原位细乳液聚合工艺,以过氧化氢异丙苯-四乙烯五胺为氧化还原引发体系制备了粒径在150 nm左右、含硅质量分数高达63%、规整性较好的树莓状纳米复合微球。研究发现加入聚苯乙烯提高了体系的稳定性;γ-甲基丙烯酰氧基丙基三甲氧基硅烷不仅可作为功能单体参与二氧化硅的改性,同时也可起到增容剂的作用。     

γ-甲基丙烯酰氧丙基三(三甲基硅氧基)硅烷的制备及其乳液聚合研究

通过 γ-甲基丙烯酰氧丙基三甲氧基硅烷 ( KH-5 70 )与三甲基氯硅烷共水解 ,进一步发生缩合反应 ,制备了γ-甲基丙烯酰氧丙基三 (三甲基硅氧基 )硅烷。并通过乳液聚合法制备了该单体的自聚乳液 ,对聚合工艺进行了初步探讨 ,用红外光谱对聚合产物进行了表征。同时 ,研究了乳化剂的种类及用量对反应的影响 ,发现采用有机硅乳化剂和阴离子乳化剂复配的乳化体系 ,可得到稳定性强、粒度适中的自聚乳液。     

硅烷偶联剂改性聚硅氧烷乳液的合成及性能研究

以γ-缩水甘油醚氧丙基三甲氧基硅烷(KH 560)、γ-甲基丙烯酰氧基丙基三甲氧基硅烷(KH 570)及八甲基环四硅氧烷(D4)为原料,十二烷基苯磺酸(DBSA)阴离子乳化剂(又作催化剂)与烷基苯酚聚氧乙烯醚(OP-10)非离子乳化剂为复合乳化剂,通过乳液聚合反应合成了性能稳定的改性聚硅氧烷乳液。讨论了KH 560、KH 570及混合单体(KH 560/KH 570)用量对聚硅氧烷乳液粒径及性能的影响。结果表明:随着KH 560用量的增加,乳液粒径逐渐增大,而分布指数先减小后增大。随着KH570用量的增加,乳胶粒粒径先增大后减小,但是粒径分布变窄。两种改性单体同时加入所合成的乳液粒径更大。硅烷偶联剂改性聚硅氧烷乳液耐高温稳定性、耐低温稳定性、离心稳定性及稀释稳定性都良好。加入KH 560单体改性的聚硅氧烷乳液,其在环境温度下成膜效果较佳。     

有机硅氧烷-丙烯酸酯乳液的合成

以丙烯酸丁酯、甲基丙烯酸甲酯、γ-甲基丙烯酰氧基丙基三甲氧基硅烷、丙烯酸及羟甲基丙烯酰胺为单体 ,通过乳液聚合制备了有机硅氧烷—丙烯酸酯乳液。考察了乳化剂、引发剂、功能单体对聚合以及乳液性能的影响。     

高硅烷含量有机硅-丙烯酸酯聚合物的制备研究

采用溶液聚合法以偶氮二异丁腈为引发剂,用γ-甲基丙烯酰氧基丙基三甲氧基硅烷(KH-570)、γ-甲基丙烯酰氧基丙基甲基二甲氧基硅烷(KH-571)、(甲基)丙烯酸酯类单体,合成有机硅单体含量为45%的有机硅-丙烯酸酯聚合物.考察了引发剂用量及其种类与转化率之间的关系,硅烷配比、溶剂配比对体系的影响.FT-IR表明:有机硅单体参与了共聚.     

有机硅改性丙烯酸酯乳液的性能研究

采用γ-甲基丙烯酰氧基丙基三甲基硅烷(KH 570改性丙烯酸酯类聚合物,合成了丙烯酸酯聚合乳液,研究了单体配比、乳化剂用量、聚合方法对乳液性能的影响.结果表明:单体配比MMA∶BA∶MAA=54∶44∶2,乳化剂用量为3%时,乳液的综合性能较好.     

MPS/OTES共聚乳液的制备与性能研究

选用γ-甲基丙烯酰氧基丙基三甲氧基硅烷（MPS）和辛基三乙氧基硅烷（OTES）为共聚单体，十二烷基硫酸钠（SDS）和聚氧乙烯辛基苯酚醚-10(OP-10)为乳化体系，采用乳液聚合方法成功制备了稳定的MPS/OTES乳液。探究了不同工艺条件对乳胶粒粒径和乳液性能的影响，利用FT-IR、SEM、TEM、纳米粒度和电位分析仪等对乳胶粒形态和结构进行了分析。结果表明：随着单体MPS质量比的增加，乳液粒径先减小后增大，MPS:OTES=2:1时，乳液的粒径最小；当酸性催化剂DBSA用量为1.33～1.67%时，乳液粒径在100 nm左右，粒径分布较窄，乳液稀释稳定性、离心稳定性、储存稳定性良好。     

Synthesis and properties of branched organosilicon-acrylate copolymer latexes

Summary Stable organosilicon-acrylate copolymer latexes with high silicon content were prepared by seeded semibatch emulsion polymerization of butyl acrylate (BA), methyl methacrylate (MMA) with a novel branched organosilicon monomer 3-methacryloxypropyl tris(trimethylsiloxy) silane (MPTS). Monomer conversion, evolution of the particle size and its distribution were monitored by dynamic light scattering. The effects of MPTS on the polymerization kinetics, the nucleation mechanism and properties of latex were investigated. The results indicated that, in addition to micellar nucleation, a coagulative nucleation step was also observed as a result of the addition of the organosilicon monomer, accordingly, the particle number of the silicon-acrylate latexes increased, the average particle diameter decreased and the polymerization rate accordingly increased compared to those of the acrylate latexes without organosilicon monomer. Moreover, the particle size distribution presented bimodal curves, which indicated that there were large particles formed at an early stage. However, the particle size distribution curves became monomodal at the later stage, and the final latex shows a narrow particle size distribution. It was found that the properties of latex and latex film were obviously influenced by MPTS content. With increasing MPTS content, latex film glass transition temperature and water absorption ratio decreased, the degradation temperature and water contact angle were increased. Hence, the resulting latex films containing MPTS showed lower glass transition temperature and excellent water-resistance, which probably due to the incorporation of the bulky branched hydrophobic group of MPTS into the copolymer chains.     

Fabrication and characterization of polysiloxane/polyacrylate composite latexes with balanced water vapor permeability and mechanical properties: effect of silane coupling agent

In order to improve the water vapor permeability and mechanical properties of latex films, polysiloxane/polyacrylate (PSi/PA) composite latexes were fabricated via seeded emulsion polymerization of methyl methacrylate and butyl acrylate onto PSi latex particles, and the effects of the silane coupling agent 3-methacryloyloxypropyl trimethoxysilane (MATS) on the morphologies of the latex particles and films, as well as the microphase separation degree, the water vapor permeability and the mechanical properties of the latex films were investigated. Results indicated that MATS was essential for obtaining the PSi/PA composite latex particles with PSi as core and PA as shell and made a great contribution to restrict the phase separation. The PSi/PA core/shell latex films showed similar tensile strength and elongation with pure PA film, while exhibiting promising water vapor permeability. It was found that the influences of MATS content on the water vapor permeability and mechanical properties were opposite, and on the premise of the requirements for mechanical properties, lower MATS content could provide the PSi/PA core/shell latex films with better water vapor permeability.     

Preparation in presence of urushiol and properties of acrylate latex with interparticle bridges

Acrylate latices were prepared by seeded emulsion polymerization of methyl methacrylate (MMA) and butyl acrylate (BA) in presence of urushiol with multifunctional groups (0–6 wt%). The emulsion polymerization was strongly influenced by the urushiol content. With increasing urushiol content, the conversion rate of the monomers first increased then decreased, the stability of emulsion polymerization gradually declined, the average particle size of the latex increased from 115.9 to 175.3 nm, and a change from mono- to bimodal particle size distribution occurred. Interestingly, transmission electron microscopy (TEM) showed that some particles were connected by linear bridges in presence of urushiol. Based on results of ¹H nuclear magnetic resonance (NMR) analysis, such formation of interparticle bridges is due to participation of urushiol in the emulsion polymerization of the acrylate monomers. The content of urushiol also affected the properties of latex films. With increasing urushiol content from 0 to 3 wt%, the adhesion, pencil hardness, and contact angle were markedly improved from grade 6 to grade 2, from B to 3H, and from 22° to 61°, respectively, due to formation of interparticle bridges. When the content of urushiol exceeded 3 wt%, the adhesion and pencil hardness remained unchanged, but the water contact angle markedly declined because of higher surface roughness of the latex film. Furthermore, addition of urushiol enhanced the thermal stability of the latex films.     

有机-无机杂化核壳型乳胶粒的制备及其粒径控制

以苯乙烯乳液聚合合成种子,再在种子外生成苯乙烯与甲基丙烯酸-3-三甲氧基硅丙酯（MPS）的共聚物,利用MPS中硅氧烷基的水解-缩合反应,形成交联的壳,得到有机-无机杂化型核壳乳胶粒.然后用溶剂将聚苯乙烯模板溶解,可得到空心微胶囊.通过透射电镜（TEM）和动态光散射粒径仪（DLS）观测乳胶粒及微胶囊的形态.并研究了乳化剂种类、介质pH值、MPS用量和加入方式对粒径、粒子数和体系稳定性的影响.发现非离子型乳化剂、酸性或碱性介质、MPS用量过多均促进乳胶粒子数减少,减弱了乳液稳定性.而采取连续滴加MPS的方法则可提高乳液的稳定性,且粒径可控.     

The surface modification of nanosilica,preparation of nanosilica/acrylic core‐shell composite latex,and its application in toughening PVC matrix

The properties and morphology of nanosilica modified with silane coupling agent, methacryloxypropyltrimethoxysilane (MPS), were characterized by fourier transform infrared, zeta potentials, thermogravimetric analysis, and transmission electron microscopy. The results showed that the grafting ratio of MPS on the surface of nanosilica increased with the MPS content. MPS‐silica/PBA/PMMA core‐shell latexes (MPS‐Si/ACR) were prepared by seeded emulsion polymerization. Then they were used to mix with PVC resin. The outer layer (PMMA) enhanced the dispersibility of MPS‐Si/ACR in the PVC matrix by increasing the interfacial interaction of these composite particles with PVC. The notched impact strengths of the blends were influenced by the weight ratio of MPS to silica, the concentration of emulsifier (SDS), and the MPS‐Si/ACR content. The relationships between the mechanical properties and the core‐shell composite structures were elaborated. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008     

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。     

壳层含硅的丙烯酸酯核壳乳液研究

以半连续滴加法制备壳层含γ-(甲基丙烯酰氧基 ) -丙基三甲氧基硅烷的丙烯酸酯核 -壳乳液。探讨了聚合条件对聚合反应的影响 ,并确定了最佳聚合条件。以红外光谱 (IR)、热分析仪 (TGA、DSC)、动态表面能分析仪、透射电子显微镜 (TEM)表征乳胶的性质及结构。     

高固含量丙烯酸酯乳液压敏胶制备及性能

以丙烯酸丁酯（BA）、甲基丙烯酸甲酯（MMA）、丙烯酸（AA）、丙烯酸羟乙酯（HEA）为共聚单体，以烯丙氧基脂肪醇聚氧乙烯醚硫酸铵(SR-10)和烷基聚氧乙烯醚琥珀酸单酯磺酸二钠（A-102）作为环保型复合乳化剂，通过无种子半连续乳液聚合工艺制备了固含量高达62%的丙烯酸酯乳液压敏胶。考察了硬单体MMA用量对乳液压敏胶性能的影响。结果表明：当MMA用量为10%（以单体总质量计，下同）时，高固含量丙烯酸酯乳液压敏胶玻璃化转变温度（Tg）为-32.6 ℃，初始热分解温度为337 ℃，水接触角为108°，环形初黏为9.53 N/25mm，180°剥离强度为10.08 N/25mm，持黏力超过72 h；与未添加MMA的高固含量乳液相比，添加10% MMA后乳液黏度从361 mPa·s降至155 mPa·s，粒径从375 nm降至350 nm，粒径分布指数从0.144增至0.214。     

微波辐射强化制备含氟硅丙烯酸酯共聚物乳液

采用多步种子乳液聚合法,以丙烯酸丁酯、甲基丙烯酸甲酯、g-(甲基丙烯酰氧)丙基三甲氧基硅烷和甲基丙烯酸六氟丁酯为原料在微波辐射下制备了核-壳型含氟硅丙烯酸酯共聚物乳液. 并研究了共聚物的结构、乳胶粒的形态和聚合过程中粒径的变化. 结果表明,所得乳胶粒子呈核-壳结构,与常规加热相比,微波的引用能加快反应速率,形成核-壳结构. 壳层富集含氟硅聚合物的核-壳形态有利于含氟硅结构单元在聚合物膜表面的分布,当氟硅单体为6%(w)时,乳胶膜对水的接触角达91.3o. 加入氟硅组分显著提高了聚合物膜的耐水性,当其含量从0增大到18%时,乳胶膜的吸水率从20.1%降低到3.54%.     

A novel method for preparing composites of PDMS/PS core–shell emulsion and polystyrene

A novel and simple method for preparing composites of PDMS/PS core–shell emulsion and polystyrene was reported. This method was based on emulsion and suspension in situ polymerization. The relationship between the process of core–shell emulsion breaking and electrolyte concentration was studied by spectrophotometry. The results of transmission electron microscopy showed that polydimethylsiloxane soft particles were dispersed uniformly in the composites. Diameters of the composite beads ranged from 0.5 to 4.0 mm, which could be controlled by adjusting the amount of hydroxyapatite. At last, the properties of the latex film including water absorption ratio, contact angle, pendulum hardness and transparency were tested. The results showed that the content of emulsion obvious affected the properties. During the process of emulsion and suspension in situ polymerization, the contact angle of the latex films ascended to 106.06° and the transmission ratio at 500 nm decreased to 0.3 with the increasing of core–shell emulsion. Whereas, the absorption and pendulum hardness fell to 0.37% and 322 S, respectively. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007