聚硅氧烷聚丙烯酸酯改性聚氨酯三元复合乳液中偶联剂丙烯酸羟乙酯的作用

用异佛尔酮二异氰酸酯与仲羟基封端的聚硅氧烷( PMTS)反应在PMTS分子链端引入异氰酸酯基团,然后将其与聚丙二醇反应制得聚硅氧烷改性聚氨酯( PSU)预聚体,最后加入丙烯酸酯单体(AC)通过乳液聚合制备了非偶联型聚硅氧烷聚丙烯酸酯改性聚氨酯( PSU-AC)三元复合乳液.在PSU与AC聚合时加入丙烯酸羟乙酯(HEA)...     

有机硅-聚氨酯共聚乳液的制备和乳胶膜相结构及其性能研究

以端羟丙基聚二甲基硅氧烷(HP-PDMS)、异佛尔酮二异氰酸酯、2,2-二羟甲基丁酸等为主要原料,采用分步投料法和无皂相反转乳化工艺制得粒径约50 nm的有机硅-聚氨酯共聚乳液,并对有机硅-聚氨酯乳胶膜的相结构和性能进行了表征,考察了HP-PDMS用量对乳胶膜相结构和性能的影响.DSC测试结果显示,与聚醚型聚氨酯乳胶膜相比,有机硅-聚氨酯乳胶膜中存在明显的相分离结构.FTIR分析结果表明,有机硅-聚氨酯乳胶膜硬段之间存在较强的氢键,它促进了相分离结构的形成.从AFM相图上可以观察到有机硅-聚氨酯乳胶膜中存在明显的海岛型相分离结构,其中聚硅氧烷软段的无定形微区构成了岛状分散相.随着有机硅含量的增加,有机硅-聚氨酯乳胶膜的相分离程度增加,弹性模量降低,断裂伸长率和柔韧性显著升高.有机硅-聚氨酯乳胶膜的起始分解温度低于聚醚型聚氨酯乳胶膜,但其在高温阶段的稳定性明显优于后者;对乳胶膜接触角和吸水率的研究表明,有机硅-聚氨酯乳胶膜的耐水性远高于聚醚型聚氨酯乳胶膜.     

甲基丙烯酸羟乙酯改性水性聚氨酯乳液的制备及性能

采用种子溶胀乳液聚合法,以水性聚氨酯为种子,甲基丙烯酸羟乙酯、甲基丙烯酸甲酯和丙烯酸丁酯为单体制备水性聚氨酯丙烯酸酯复合乳液,考察了甲基丙烯酸羟乙酯含量对复合乳液的T型剥离、胶膜的硬度、耐水性和力学性能的影响。结果表明,随着甲基丙烯酸羟乙酯含量的增加,复合乳液的T型剥离强度、胶膜的硬度和拉伸强度增大,胶膜的耐水性先增大后减小,断裂伸长率有所降低,适宜的甲基丙烯酸羟乙酯用量为3%。     

含氟聚氨酯-丙烯酸酯核壳乳液的制备及性能

以甲基丙烯酸羟乙酯封端的水性聚氨酯作为大分子单体,与甲基丙烯酸甲酯及甲基丙烯酸全氟烷基乙基酯在乳液中进行自由基共聚合,制备出具有核壳结构的水性含氟聚氨酯-丙烯酸酯乳液。通过激光粒度分析仪、FT-IR、DSC、TGA、接触角、力学等表征手段,对乳液及其乳胶膜的结构和性能进行了研究,还着重探讨了甲基丙烯酸全氟烷基乙基酯的含量对乳胶膜性能的影响,结果表明:所制得的材料具有预期结构,并且具有优异的表面性能和力学性能,氟单体的引入使乳胶膜的表面能大大降低,而力学性能明显提高。     

有机硅改性磺酸型聚氨酯/丙烯酸酯复合乳液的制备

将磺酸型聚酯多元醇、异佛尔酮二异氰酸酯（IPDI)和三羟甲基丙烷(TMP)在无有机溶剂参与的情况下进行预缩聚,以硅烷偶联剂γ-氨丙基三乙氧基硅烷（KH550）作为改性剂,加入双官能团单体甲基丙烯酸-β-羟乙酯(HEMA),得到含乙烯基和有机硅封端的聚氨酯作为种子乳液,然后与甲基丙烯酸甲酯(MMA)、丙烯酸丁酯(BA)混合单体共聚,合成了有机硅改性磺酸型聚氨酯/丙烯酸酯复合乳液。 红外光谱的表征确定了有机硅改性磺酸型聚氨酯/丙烯酸酯复合乳液的化学结构;透射电子显微镜观察证实了此复合乳液具有明显的核壳结构;热重分析表明,经有机硅和丙烯酸酯改性后,胶膜的最大热失重温度提高了20 ℃,X射线衍射分析表明胶膜的结晶度降低,有利于提高膜的韧性。 力学性能测试及吸水率测试结果表明,当有机硅含量为1.9%时,胶膜的拉伸强度最高达到25.03 MPa,断裂伸长率为328%,此时膜的吸水率最低。     

单油酸三羟甲基丙烷酯改性水性聚氨酯

利用单油酸三羟甲基丙烷酯(TMPM)、异佛尔酮二异氰酸酯(IPDI)和聚氧化丙烯(PPG)等制备水性聚氨酯。采用透射电镜(TEM)、动态激光光散射(DLLS)、红外光谱(FT-IR)、热重分析(TGA)和表面张力仪表征了乳液胶束形态、产物结构及性能。结果表明:水性聚氨酯(PU)分子上引入脂肪侧链容易在水中形成规整的胶束,但TMPM改性的水性聚氨酯胶束粒径随TMPM含量的增加不断增大,当w(TMPM)=0.07时,乳液不稳定;脂肪侧链的引入降低了水性聚氨酯乳液的表面张力,表面张力随着反应体系中—NCO和—OH摩尔比的增大而降低,随交联度的增大先增加后减小;TMPM的引入可以提高胶膜的热稳定性。     

PU-St超浓乳液聚合动力学及聚合物性质的研究

采用一步法制备聚氨酯预聚体 ( PU)苯乙烯 ( St)超浓乳液 ,探讨了稳定的超浓乳液的 NCO/OH和 St/PU最佳比例范围。研究了乳化剂和引发剂浓度对超浓乳液聚合的稳定性及聚合动力学的影响 ,并制得了用 PU改性的聚苯乙烯 ( PS)粉状树脂。测定了乳胶粒子大小、粒径分布、分子量和聚合物膜的动态力学性质。发现乳胶粒子大小及其单分散性随聚合转化率的增加而增加 ;与本体聚合比较 ,聚合物的分子量有明显增大 ;PU- PS复合聚合物具有优良性能。     

中和度对聚酯型阴离子水性聚氨酯性能的影响

采用预聚体法,以聚酯多元醇、甲苯二异氰酸酯、二羟甲基丙酸（DMPA）制备了聚酯型阴离子水性聚氨酯乳液,考察了中和度对乳液的粒径、运动黏度以及胶膜力学性能的影响。结果表明,随着中和度的增加,水性聚氨酯乳液的粒径减小;运动黏度增大;水性聚氨酯胶膜的耐水性先增大后减小;胶膜的拉伸强度提高,但其断裂伸长率降低。以三乙胺为中和剂...     

~5O-MMT/BA-VAc原位共聚乳液的制备及胶膜性能研究

采用原位乳液聚合方法,制备了O-MMT/BA-VAc复合乳液,对复合乳液及胶膜的性能进行了详细研究。研究结果表明:当O-MMT引入量小于0.8wt.%时,乳液的聚合稳定性以及储存稳定性较好;复合胶膜的耐水性能随着O-MMT引入量的增大呈先增强后减弱趋势,当改性MMT用量为0.5wt.%时,复合胶膜具有最佳耐水性能,吸水率比BA-VAc胶膜降低了75%,相同添加量下,复合胶膜达到最佳拉伸强度,为22.9MPa。     

原位聚合法制备聚醋酸乙烯酯/纳米SiO2复合乳液

采用原位乳液聚合法制备了聚醋酸乙烯酯／纳米二氧化硅复合浮液。用红外光谱、原子力显微镜以及透射电镜等现代测试手段对复合材料进行了表征．考察了纳米二氧化硅在聚醋酸乙烯酯乳液中的分散状况及纳米二氧化硅用量对复合浮液性能的影响。结果表明：随纳米二氧化硅用量增加,复合乳液的干态,湿态粘接强度均而明显提高;乳液的粘度减小;复合乳液的胶膜耐热性提高。     

Coagulation of Carboxylic Acid-Functionalized Latexes

In the present work, the stability of particles produced by emulsion polymerization and stabilized by carboxylic acid groups was studied from turbidity measurements. To achieve this, a number of copolymerization runs was carried out under different reaction conditions, including the use of different carboxylic monomers. Partitioning analyses using conductimetric and potentiometric titrations were performed in order to assess the distribution of carboxylic monomers among the main phases of the produced latexes. Additionally, the stability and coalescence of particles were measured by turbidimetry in a diluted latex considering either the presence or not of the anionic surfactant sodium lauryl sulfate. Coalescence of particles was provoked in the latex samples at different temperatures by addition of an aliquot of a concentrated solution of electrolyte. The influence of surfactant, temperature and type of carboxylic acid group on the particle stability was investigated.     

含氟/硅丙烯酸酯乳液的合成进展

含氟丙烯酸酯聚合物具有良好的成膜性、光泽性、柔韧性、耐污性及耐腐蚀性,广泛应用于防腐耐候涂料。但其对基体的附着性差,对颜料、填料的润湿性差,不耐低温,加之含氟丙烯酸酯单体价格昂贵,大量使用受到限制。含氟/硅丙烯酸酯共聚物不仅兼备了含氟聚合物的诸多优良性能,而且能有效地提高与基体的附着力并降低聚合物成本。本文综述了氟/硅改性丙烯酸酯乳液常用单体;核壳型乳胶粒的结构及影响因素;氟/硅丙烯酸酯共聚物合成路线。     

聚合物胶乳的立体稳定性

本文首先叙述了影响聚合物胶乳稳定性的各种效应,然后着重介绍了立体稳定的基本原理。     

有机硅改性丙烯酸酯乳液的合成

乳液聚合;涂料;有机硅改性丙烯酸酯乳液的合成     

Well-Characterized Monodisperse Latexes as Model Colloids

Monodisperse polystyrene latexes prepared with persulfate-ion initiator can be ion exchanged to remove the adsorbed emulsifier and solute electrolyte. Rigorous purification of the ion-exchange'resins is necessary to avoid contamination with leached polyelectrolytes. These ion-exchanged latexes are stabilized with the residual sulfate end-groups of the polymer molecules, the number of which is determined by conductoroetric titration. The result is a dispersion of monodisperse spheres with-a constant and known surface charge due to chemically-bound strong-acid groups. These latexes are ideal models for colloidal studies. Preliminary experiments of stability, adsorption, sedimentation, viscosity, interference colors, and conductance give consistent results, e.g., the particle double-layer interactions determined by viscosity are in accord -with the particle spacings estimated from interference colors, the double-layer parameters estimated from conductometric titration and conductance measurements account for the measured decrease in sedimentation rate due to double-layer interactions, and the molecular area of sodium dodecyl sulfate measured by adsorption in latex is in agreement with literature values.     

Modification of Synthetic Latexes with Colloidal Silver

Butadiene-styrene and acrylate latexes were studied as matrices for preparing colloidal silver. Colloidal-chemical and strength properties of the modified latexes and Primal E1950 latex films were studied. The heat resistance of these materials was determined.     

Compound Latexes for Antistatic Coatings

Compound latexes based on amine-containing styrene-acrylate copolymers and hollow particles of a polystyrene-based copolymer as a filler were studied. With this filler, it is possible to prepare antistatic pigmented coatings with increased surface hardness, decreased density, and surface resistivity _s of the order of 10⁸ .     

Mucin Interactions with Functionalized Polystyrene Latexes

The interactions of pig gastric mucin and bovine submaxillary mucin with carboxylate (PCM) and amino (PAM) polystyrene latexes with 750 and 1000 nm diameters have been studied in vitro. The mucin interaction increased when the pH decreased from 7.4 to 3.0 and when the electrolyte concentration increased from 86 to 205 mM. The driving force of the interaction was very probably nonionic. Under certain conditions, electrostatic attraction also was important for PAM. Under all experimental conditions tested, the mucins interacted less with PAM than with PCM. The functional groups of the latexes directed the conformation of the adsorbed mucins at the interface. At low pH, the mucins probably were adsorbed in multilayers.     

Zinc-Containing Polymers and Their Latexes: Structure and Properties

This work deals with the polymer latexes synthesized using zinc-containing monomers. The effect of the ligand environment of the zinc-containing monomers on the colloidal and rheological properties of the latexes, as well as on mechanical properties of their films is studied. Mixed zinc salts containing the residues of saturated and unsaturated carboxylic acids are shown to be more efficient cross-linking agents than the symmetric salts of this metal.     

纳米粘土对硅丙乳液的改性

采用原位乳液聚合方法,以纳米粘土改性硅丙乳液,并对所得复合乳液及其涂膜性能进行了研究,结果表明:复合乳液的储能模量、损耗因子和复合粘度较纯硅丙乳液均有明显提高,且其涂膜的耐热性能增强并具有优良的综合性能。