有机硅改性聚氨酯丙烯酸酯细乳液的制备及性能

将自制的聚氨酯大单体与含乙烯基有机硅单体、丙烯酸酯进行共聚反应,通过合适的工艺条件,制备了一系列性能稳定的细乳液。研究了聚合方法、有机硅含量对共聚细乳液及胶膜性能的影响。结果表明,种子细乳液法制得的聚合物结构明确,细乳液粒径均在150 nm左右,分布指数约为0.07,有机硅的引入使乳液胶膜耐水性及耐高温性得到了明显提高。     

苯丙水溶胶的合成与性能研究(I) 聚合工艺和反应组分对聚合稳定性和胶体性能的影响

用一次投料法、半连续滴加法和单体预乳化法三种聚合工艺，合成了苯丙乳液聚合物，并加氨微细化，转化成水溶胶，考察了聚合工艺和反应组分（乳化剂，功能单体等）对苯丙乳液及其水溶胶反应稳定性和粒子大小及分布等胶体性能的影响。     

室温交联型硅丙微胶乳的合成研究(1)硅烷单体对聚合稳定性和胶膜性能的影响

采用种子微乳液聚合工艺和单体半连续滴加法合成了室温交联型有机硅改性丙烯酸酯微胶乳，研究了硅烷单体种类和用量及其添加顺序等对聚合稳定和胶膜性能的影响。结果表明，使用含阻碍性铁新硅烷单体（C－1757）可明显抑制体系中的水解－缩合反应，提高聚合稳定性，而且随其用量增加，改性胶膜的交联密度增大，拉伸强度提高；延迟添加C－1757，可进一步提高聚合稳定性，但会降低胶膜的交联密度，拉伸强度先高后低，30／70处有一个最大值，所合成的硅丙微胶乳储存期可达长两年，与C－1757相比，硅烷单体A－174改性的胶膜具有更大的交联密度，而A－171改性的胶膜交联密度偏低，力学性能较差。     

含氢聚甲基硅氧烷／丙烯酸丁酯／羟甲基丙烯酰胺复合乳液的制备方法对 …

采用自由基引发剂用３种不同的聚合方法制备了新型的含氢聚甲基硅氧烷（ＰＨＭＳ）／丙烯酸丁酯（ＢＡ）／羟甲基丙烯酰胺（ＮＭＡ）复合聚合物乳液，详细他不同聚合方法对乳液稳定性和乳胶粒子的影响。同时对聚合反应的机理，产物的结构作了考察，结果表明：通过乳液聚合，得到了ＰＨＭＳ／ＢＡ／ＮＭＡ共聚物，单体乳液滴加法所得乳液粒径较小，乳液性能稳定，是制备ＰＨＭＳ／ＢＡ／ＮＭＲ复合聚合物乳淤较适宜的方法。     

含氢聚甲基硅氧烷/丙烯酸丁酯/羟甲基丙烯酰胺复合乳液的制备方法对乳液性质的影响

采用自由基引发剂用３种不同的聚合方法制备了新型的含氢聚甲基硅氧烷（ＰＨＭＳ）／丙烯酸丁酯（ＢＡ）／羟甲基丙烯酰胺（ＮＭＡ）复合聚合物乳液。详细讨论了不同聚合方法对乳液稳定性和乳胶粒子的影响，同时对聚合反应的机理、产物的结构作了考察．结果表明：通过乳液聚合，得到了ＰＨＭＳ／ＢＡ／ＮＭＡ共聚物；单体乳液滴加法所得乳液粒径较小，乳液性能稳定，是制备ＰＨＭＳ／ＢＡ／ＮＭＡ复合聚合物乳液较适宜的方法．     

多乙烯基硅油改性丙烯酸酯乳液的合成及性能

以自制阳离子型乳化剂H、多乙烯基硅油和丙烯酸类单体为主要原料,采用一步法和半连续种子乳液聚合法合成有机硅改性丙烯酸酯乳液。研究了不同聚合方法、不同有机硅含量对硅丙乳液乳胶膜的吸水率、疏水性能的影响,通过纳米粒度-Zeta电位分析仪、接触角仪、红外光谱、透射电镜对乳液及聚合物结构进行了表征。结果表明有机硅单体参与了聚合,乳液稳定性好、平均粒径小。采用半连续种子乳液聚合法合成乳液,有机硅最大添加量为40%(占壳层单体总量),乳胶膜的吸水率只有3.2%,对水的接触角达到105.2o。     

室温自交联丙烯酸酯乳液的制备与表征

使用3种含不饱和双键硅氧烷,乙烯基三(β-甲氧基乙氧基)硅烷(A172)、乙烯基三乙氧基硅烷(VTES)和γ-甲基丙烯酰氧丙基三甲氧基硅烷(A174)为功能单体,采用半连续乳液聚合法制备了室温自交联丙烯酸酯乳液,探讨了硅氧烷功能单体在不同pH条件下水解情况以及其种类和用量对乳液及乳胶膜性能的影响.结果表明,pH在7～9之间时硅氧烷功能单体水解最慢;A172在pH为8.4时5h内就水解完全;增加VTES和A174的用量均能提高乳胶膜的交联度、力学性能和耐水性.控制聚合过程的pH值以抑制硅氧烷功能单体的水解并调节乳液成膜时的pH值以加速硅氧烷功能单体的水解从而增强胶膜的交联程度,发现酸性或碱性条件下得到乳胶膜比中性条件下胶膜的力学和耐水性能均有不同程度的提高,并且在酸性条件下胶膜的性能提高最多.对比使用A174和VTES制备的胶膜,发现这种方法对含有A174胶膜的效果不明显,而含VTES胶膜的性能提高最为显著.     

苯丙水溶胶的合成与性能研究(II) 水溶胶的转化及其流变性能

用一次投料法、半连续滴加法和单体预乳化法3种聚合工艺，合成了苯丙乳液聚合物，并加氨微细化，转化成水溶胶，研究了水溶胶的氨化反应对乳胶粒子大小及微观形成的影响。并考察了水溶胶的流变性能。     

水性聚氨酯胶粘剂结构与性能的研究

以聚醚烽异氟尔酮二异氰酸酯为主要原料,以二羟甲基酸为亲水单体制备了一组不同配方组成的聚氨酯乳胶粘剂。通过粘度测定、粒度分析、力度性能的测试以及DSC分析,研究了新水剂含量、软链段的类型和加料方法对乳液及其胶膜性能的影响。结果表明：二羟甲基丙酸含量在3％－8％之间可获得比较稳定的乳液,并且两步法较一步法制得的乳液分散性好,但胶膜力学性能方面,一步法较好。     

荧光探针法研究核壳结构有机硅-丙烯酸酯乳液的聚合行为

以芘为荧光探针,探讨了有机硅-丙烯酸酯核壳乳液聚合过程中,芘的第一振动峰(373 nm处)与第三振动峰(384 nm处)荧光强度的比值I1/I3与乳化剂、有机硅单体(D4)和引发剂(KPS)用量之间的关系,并结合聚合过程中探针芘的I1/I3峰值与单体转化率及乳胶粒形态演变之间的关系,研究了核壳结构有机硅-丙烯酸酯乳液的聚合行为.研究结果表明,探针芘的I1/I3峰值随乳化剂用量,D4用量,KPS用量不同发生相应的变化,随单体转化率的增加而增大.当乳化剂用量、D4用量、KPS与总单体的质量比依次为2 g、8 g、0.7%时,得到的乳液具有优良的综合性能.聚合反应过程中,当种子乳胶粒转变为核壳乳胶粒时,芘的I1/I3峰值仍呈现出明显的转变,说明有机硅-丙烯酸酯核壳乳液具有互穿聚合物网络结构.因此,荧光探针可用于研究有机硅-丙烯酸酯核壳乳液聚合反应进程.     

PREPARATION AND PROPERTIES OF SILICONE-ACRYLATE COPOLYMER LATEX

Silicone-acrylate copolymer latex was prepared through three different polymerization processes, i.e., the batch process, preemulsified monomer addition and the monomer addition process. The results revealed that the monomer addition process is a desirable approach to produce narrow particle size distribution latex with higher polymerization conversion and less amount of coagulum. The effect of silicone content on the glossiness and water absorption of latex film was investigated and the results showed that the glossiness of latex film is improved up to a silicone content of 10% of total monomers, but becomes impaired thereafter, whereas water absorption is reduced accordingly.     

MMA-EA-AA无皂乳液聚合中粒径及粒径分布的控制

系统研究了MMA EA AA三元无皂乳液聚合体系中各种因素对乳胶粒大小及分布的影响 ,制得了单分散、粒径在 30 0～ 6 0 0nm可控聚合物乳胶粒 .结果表明 ,在过硫酸铵用量一定的条件下 ,聚合初期加入大量引发剂可同时提高单体转化率和乳胶粒的单分散性 ;随着引发剂和AA用量的增加以及聚合温度的升高 ,胶粒粒径逐渐减小 ,转化率逐渐升高 ;随着NH4 HCO3用量的增加 ,粒径逐渐增大 ,当NH4 HCO3用量达到 0 5g以后 ,转化率逐渐降低 ;搅拌速率为 30 0r min左右时 ,单体转化率最高 ,所得乳胶粒粒径最均一 .     

Synthesis and characterization of novel polyacid-stabilized latexes

A series of novel polyacid macromonomers based on 2-hydroxypropyl methacrylate (HPMA) were prepared by atom transfer radical polymerization (ATRP) via a two-step route. First, a range of well-defined PHPMA homopolymer precursors were synthesized by ATRP using a tertiary amine-functionalized initiator, 2-(dimethylamino)ethyl-2-bromoisobutyrylamide, and a CuCl/2, 2'-bipyridine (bpy) catalyst in alcoholic media at 50 °C. ATRP polymerizations were relatively slow and poorly controlled in pure isopropanol (IPA), especially when targeting higher degrees of polymerization (DP > 30). Improved control was achieved by addition of water: low polydispersity (M(w)/M(n) < 1.25) PHPMA homopolymers of DP = 30, 40, 50, 60, or 70 were successfully prepared using a 9:1 w/w % IPA/water mixture at 50 °C. These PHPMA homopolymer precursors were then derivatized to produce the corresponding poly(2-(succinyloxy)propyl methacrylate) (PSPMA) macromonomers by quaternizing the tertiary amine end-group with excess 4-vinylbenzyl chloride, followed by esterification of the pendent hydroxyl groups using excess succinic anhydride at 20 °C. These polyacid macromonomers were evaluated as reactive steric stabilizers for polystyrene latex synthesis under either aqueous emulsion polymerization or alcoholic dispersion polymerization conditions. Near-monodisperse polystyrene latexes were obtained via aqueous emulsion polymerization using 10 wt % PSPMA macromonomer (with respect to styrene monomer) with various initiators as evidenced by scanning electron microscopy, disk centrifuge photosedimentometry and light scattering studies. PSPMA macromomer concentrations as low as 1.0 wt % also produced near-monodisperse latexes, suggesting that these PSPMA macromonomers are highly effective stabilizers. Alcoholic dispersion polymerization of styrene conducted in various ethanol/water mixtures with 10 wt % PSPMA(50) macromonomer produced relatively large near-monodisperse latexes. Increasing the water content in such formulations led to smaller latexes, as expected. Control experiments conducted with 10 wt % PSPMA(50) homopolymer produced relatively large polydisperse latexes via emulsion polymerization and only macroscopic precipitates via alcoholic dispersion polymerization. Thus the terminal styrene group on the macromonomer chains is essential for the formation of well-defined latexes. FT-IR spectroscopy indicated that these latexes contained PSPMA macromonomer, whereas (1)H NMR spectroscopy studies of dissolved latexes allowed stabilizer contents to be determined. Aqueous electrophoresis and X-ray photoelectron spectroscopy studies confirmed that the PSPMA macromonomer chains were located at the latex surface, as expected. Finally, these polyacid-stabilized polystyrene latexes exhibited excellent freeze-thaw stability and remained colloidally stable in the presence of electrolyte.     

Polymerization of styrene with ionic comonomer,nonionic comonomer,or both

Nanosized polystyrene latexes with high polymer contents were obtained from an emulsifier-free process by the polymerization of styrene with ionic comonomer, nonionic comonomer, or both. After seeding particles were generated in an initial emulsion system consisting of styrene, water, an ionic comonomer [sodium styrenesulfonate (NaSS)] or nonionic comonomer [2-hydroxyethyl methacrylate (HEMA)], and potassium persulfate, most of the styrene monomer or a mixture of styrene and HEMA was added dropwise to the polymerizing emulsion over 6 h. Stable latexes with high polystyrene contents (≤25%) were obtained. The latex particle weight-average diameters were largely reduced (41 nm) by the continuous addition of monomer(s) compared with those (117 nm) obtained by the one-pot polymerization method. Latex particles varied from about 30 to 250 nm in diameters, whereas their molar masses were within 10⁴ to 10⁵ g/mol. The effect of the comonomer concentration on the number of polystyrene particles per milliliter of latex and the weight-average molar masses of the copolymers during the polymerization are discussed. The surface compositions of the latex particles were analyzed by X-ray photoelectron spectroscopy, which indicated that the surface of the latex particles was significantly enriched in NaSS, HEMA, or both. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1634–1645, 2001     

Effect of Monomer Feeding Mode on thePreparation of Hollow Latexes with High MAA Content in the Core Latex Preparation简

In order to prepare hollow latex particles with optimum morphology based on osmotic swelling principle, three- layer core/shell latex particles with 40 wt% MAA in the core were first prepared via multistep seeded emulsion copolymerization, in which monomers were added by a semi-continuous process with monomer addition under two different forms： pure monomers＇ mixture （monomer addition）, and pre-emulsified monomers （pre-emulsion addition）. Then, the hollow latex particles with different morphologies were obtained after alkali post-treatment. Influences of the monomer feeding mode on the emulsion polymerization and the particle morphology were investigated. Results showed that the pre- emulsion addition could significantly improve the polymerization stability in each step, and greatly enhance the uniformity of shell encapsulation. The sizes of the core and core/shell latex particles obtained by the pre-emulsion addition were smaller and more uniform than those synthesized by the monomer addition, and the hollow latex particles with intact morphology were generated by alkali post-treating of the core/shell latexes prepared from the pre-emulsion addition. As the core size increased, the morphology of the post-treated particles underwent evolution from hollow to collapse. Moreover, the mechanism of the particle morphological evolution was proposed.     

有机硅-丙烯酸酯聚合物乳液合成及粒径分析

通过种子乳液半连续法合成了有机硅改性丙烯酸酯聚合物乳液,并对其粒子形态及分布进行分析。结果表明:通过种子乳液半连续聚合工艺可制备出固含量42wt%,乳化剂含量4wt%(基于单体量)、窄分布纳米粒子的有机硅改性丙烯酸酯聚合物乳液。随反应进行,粒径分布变窄,平均粒径逐渐增大。随乳化剂中SDS与OP-10的摩尔比减少,粒径增大。     

Synthesis of Sub-100 nm and Narrow Particle Size Distribution Cationic Latex by One-Step Emulsion Polymerization

A novel approach to synthesize narrow particle size distribution cationic latex particles based on styrene and butyl acrylate was proposed. The effect of monomer/water ratios, surfactant (cetyltrimethylammonium chloride) concentrations, and monomer compositions on the evolution of particle size, distribution, number, and morphology as a function of monomer conversion was concerned in order to confirm the optimum polymerization condition. As expected, the particle size of the ultima latex increased with monomer/water ratios and styrene contents decreased with increasing surfactant concentrations. Continuous nucleation phenomena occurred when monomer/water ratio was lesser than 30/70, resulting in a gradual increase in the number of particles in the whole polymerization process. Combined with the previous work (Colloid and Polymer Science, 2014, 292: 519–525), it was concluded that particle coagulation easily took place in cationic emulsion polymerization of styrene. Thus, the narrow particle size distribution cationic latexes with particle scale between 50 nm and 80 nm, 30 wt% solid content could be prepared in a short reaction time.     

离子型共聚单体用于高固含量无皂乳液聚合的研究——甲基丙烯酸异丁酯/甲基丙烯酸甲酯/丙烯酸丁酯无皂乳液聚合体系

该文采用自行合成的一种带亲水性磺酸离子基团及羟基的可共聚单体 3 烯丙氧基 2 羟基丙磺酸钠(AHPS)用于甲基丙烯酸异丁酯 /甲基丙烯酸甲酯 /丙烯酸丁酯 (IBMA/MMA/BA)无皂乳液聚合体系 .对乳胶粒粒径大小、乳液流体力学行为、共聚物的动态力学性质、拉伸行为及耐水性进行了研究 ,并对乳胶粒的成核机理进行了探讨 .实验结果表明 ,带亲水性离子基团可共聚单体AHPS的加入可获得 0 6μm左右的乳胶粒 ,乳液固含量可达 60 % ,表现粘度测定结果表明乳液呈Bingham流体 .三元共聚物在动态粘弹谱图上只出现单一的玻璃化转变温度峰 ,是完全的无规共聚物 ,拉伸强度明显大于常规乳液聚合方法得到的聚合物 ,耐水性也得到显著提高 .     

含氟丙烯酸酯共聚乳液的制备及表征

采用十二烷基硫酸钠和壬基酚聚氧乙烯醚(OP-10)混合乳化剂，制备了粒径为40-50nm的甲基丙烯酸全氟辛基乙酯(FMA8)-甲基丙烯酸丁酯(BMA)-甲基丙烯酸(MA)共聚物乳液。通过DSC、、FTIR、^1H-NMR等手段对共聚物进行了表征。考察了乳液的稳定性、乳胶膜的吸水性和耐溶剂性以及全氟单体的含量对聚合反应的影响。