水性可紫外光固化的硫代聚氨酯分散体的制备

本文利用巯基-点击化学制备了一系列水性可光固化的硫代聚氨酯分散体,即通过连续的巯基-异氰酸酯和巯基-迈克尔加成反应分别合成硫代聚氨酯和聚硫醚：首先,二异氰酸酯与过量的二元硫醇反应生成端基为巯基的硫代聚氨酯低聚物,然后与合成的二丙烯酸酯单甲基丙烯酸酯进行巯基-迈克尔加成反应,得到侧基为甲基丙烯酸酯的硫代聚氨酯树脂,最后,巯基乙酸与端基上的丙烯酸酯反应,提供树脂的亲水基团。将树脂分散在水中后,得到半透明的可光固化硫代聚氨酯分散体。树脂的主链上含有硫醚键,可以有效克服氧阻聚效应,得到较高的转化率;侧基上带有很多可光聚合的甲基丙烯酸酯基团,光聚合后固化膜的交联密度非常高,因而也具有较高的玻璃化转变温度。     

电子束固化含氟聚氨酯丙烯酸酯的制备与性能

以六亚甲基二异氰酸酯三聚体、丙烯酸羟乙酯及羟基含氟丙烯酸酯为原料制备了电子束固化含氟聚氨酯丙烯酸酯预聚物. 通过傅里叶变换红外光谱(FTIR)和核磁共振氢谱(¹H NMR)对产物进行了表征. 研究了产物与溶剂组成的两相混合体系的流变性能、电子束固化行为及固化后涂层性能. 结果表明, 产物与溶剂混合体系具有正触变性, 绝对黏度变化符合Sedden公式, 黏流活化能约为44.8 kJ/mol. 电子束固化后涂层性能(如热稳定性、硬度、附着力和光泽度)优良.     

交联聚氨酯水分散体的合成

将硅氧烷封端的含亲水基团的线性聚氨酯预聚体分散于水中 ,获得稳定的聚氨酯分散体 .由于硅氧基团水解、缩合 ,在分散体粒子内产生扩链交联反应 ,生成了交联水基聚氨酯分散体 .透射电子显微镜研究表明分散体粒径小、分布宽 .扫描电子显微镜研究了成膜结构及成膜性能与粒径的关系 .溶胀实验计算获得的两交联点之间的平均分子量与理论平均分子量相符 .研究还发现此分散体膜在干燥过程中可进一步交联 .膜的水溶胀及机械性能表明 ,此分散体具有极大的工业应用价值 .     

亲水单体对聚氨酯-含氟丙烯酸酯复合乳液颗粒和表面性能的影响

为了提高聚氨酯-丙烯酸酯聚合物的耐水性和耐溶剂性, 将N-甲基二乙醇胺(MDEA)扩链的交联聚氨酯丙酮溶液作为反应介质, 以苯乙烯、丙烯酸丁酯、含氟丙烯酸酯(FA)为单体, 过氧化苯甲酰为引发剂, 通过溶液聚合相转化法制得新型阳离子聚氨酯-含氟丙烯酸酯复合乳液. 研究了MDEA对聚合物水分散液的乳胶粒径、Zeta电位以及乳胶膜表面性能的影响, 并用FTIR, TEM对聚合物的结构和乳胶粒形态进行了表征. 结果表明, MDEA的添加利于降低乳胶粒径, 但对乳胶膜的疏水性能有不利影响, 当MDEA的质量分数为13.15%时, FPUA乳胶粒的形态呈球形, 粒径约为253 nm, 乳胶膜的表面自由能低于25.1 mJ/m², 接触角衰减速率约为0.38 (º)/min. 另外, 乳胶膜的高温处理能够使表面自由能降低11.5%以上.     

含氟丙烯酸酯-苯乙烯共聚物的制备及其表面性能的研究

研究了聚合工艺、含氟丙烯酸酯类单体种类和用量、苯乙烯和自由基引发剂用量及硅烷偶联剂、催化剂等因素对含氟丙烯酸酯-乙烯共聚物表面性能的影响。结果表明：聚合工艺、含氟丙烯酸酯类单体种类和用量对共聚物表面的憎水性能有显著的影响;采用延时滴加含氟丙烯酸酯类单体可提高共聚物膜表面的憎水性;随含氟丙烯酸酯类单体侧链含氟烷基的链长和氟原子数及含氟单体用量的增加,共聚物水接触角增大,吸水率下降;共聚物薄膜的硬度则与含氟丙烯酸酯类单体中α-取代基、侧链含氟烷基的链长和用量、苯乙烯用量、引发剂浓度等相关;硅烷偶联剂和催化交联剂的加入可提高共聚物薄膜的强度。     

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,制得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、FT-IR、DSC、TGA、表面性能测试、力学性能测试等表征手段,对乳液及其乳胶膜的结构和性能进行了检测,另外,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,并且表面能及吸水率低,力学性能优异。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。     

聚甲基丙烯酸酯改性聚氨酯光固化水性体系研究

水性涂料;聚甲基丙烯酸酯改性聚氨酯光固化水性体系研究;接枝共聚物;聚氨酯丙烯酸酯;丙烯酸酯共聚物     

含氟三元丙烯酸酯乳液共聚物的合成及性能

含氟三元丙烯酸酯乳液共聚物的合成及性能;甲基丙烯酸甲酯;丙烯酸丁酯;含氟甲基丙烯酸酯;β-环糊精     

可用于建材防水涂料的含氟聚氨酯的研制及性能研究

以聚醚二元醇和异氰酸酯合成两端含异氰酸酯基的聚氨酯预聚物,将含氟醇与聚氨酯预聚物进行反应,得到端基含氟的聚氨酯,制备了一系列含氟聚氨酯涂料。对涂料的性能研究显示,聚合物对基材具有良好的附着力,且随着含氟量的增大,制备的含氟聚氨酯涂层对水及乙二醇的接触角数值逐渐增大,表面能和吸水率逐渐降低;聚合物体系均一,未发生相分离。表明通过化学方法将含氟链段引入聚氨酯结构,得到了稳定的含氟聚氨酯聚合物,且涂料的表面性能得到提高。该含氟聚氨酯在建材防水涂料领域有广阔的应用前景。     

自交联型含氟丙烯酸酯共聚物的合成与表征

含氟丙烯酸酯;自交联;无皂乳液;接触角滞后     

Synthesis and Surface Property of Aqueous Fluorine-Containing Polyurethane

A novel aqueous fluorine-containing polyurethane was prepared with a hydrophobic macromonomer of a perfluoroalkyl group. Two representative properties of the polyurethane, initial particle diameter dispersed in water and surface free energy of coating films, were investigated. The macromonomer was synthesized by radical copolymerization of perfluoroalkylethyl acrylate and methyl methacrylate with a diol of chain-transfer agent in order to attenuate solubility and hydrophobic property. Anionic aqueous polyurethane was obtained with a good hydrophobic film property by one-step condensation polymerization of the macromonomer with hydrophilic comonomers and successive ionization. The polyurethane showed an initial average diameter of less than 1100 nm in water and surface free energies of less than 19 dyn/cm. The water dispersion property and hydrophobic surface property of the polyurethane can be controlled by controlling the content and hydrophobic property of the macromonomer. The incorporation of the macromonomer in the polyurethane backbone did not show a significant effect on the glass transition temperature, or the softness, of the polyurethane. Copyright 2001 Academic Press.     

阴离子型含氟两亲接枝共聚物的合成及其胶束化行为研究

以聚乙二醇甲醚甲基丙烯酸酯(MPEGMA)为大分子单体,甲基丙烯酸六氟丁酯(HFMA)、对苯乙烯磺酸钠(NaSS)为共聚单体,采用大分子单体接枝共聚法,制备了一种阴离子型含氟两亲接枝共聚物P( HFMA-co-NaSS) -g-PEG.利用FTIR、1H-NMR和19F-NMR对共聚物的分子结构进行了表征.表面张力法测...     

High molecular weight monodisperse polystyrene microspheres prepared by dispersion polymerization,using a novel bifunctional macromonomer

A novel bifunctional vinyl‐terminated polyurethane macromonomer was applied to the dispersion polymerization of styrene in ethanol. Monodisperse polystyrene (PS) microspheres were successfully obtained above 15 wt % of macromonomer relative to styrene. The steep slope from the reduction of the average particle size reveals that the macromonomer can efficiently stabilize higher surface area of the particles when compared with a conventional stabilizer, poly(N‐vinylpyrrolidone). The stable and monodisperse PS microspheres having the weight‐average diameter of 1.2 μm and a good uniformity of 1.01 were obtained with 20 wt % polyurethane macromonomer. The grafting ratio of the PS calculated from ¹H NMR spectra linearly increased up to 0.048 with 20 wt % of the macromonomer. In addition, the high molecular weights (501,300 g/mol) of PS with increased glass transition and enhanced thermal degradation temperature were obtained. Thus, these results suggest that the bifunctional vinyl‐terminated polyurethane macromonomer acts as a reactive stabilizer, which gives polyurethane‐grafted PS with a high molecular weight. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3566–3573, 2005     

Heterogeneous polymerization with polyaspartate macromonomer having vinyl pendant groups. I. Synthesis of macromonomer and dispersion copolymerization of styrene

Sodium polyaspartate (PAspNa) derivatives with vinylbenzyl pendant groups (VBA‐PAspNa) were synthesized by reaction of poly(succinimide) (PSI) and vinylbenzylamine (VBA), and hydrolysis by sodium hydroxide (NaOH) solution. VBA‐PAspNa is a macromonomer with multiple vinyl groups in the side chain. Submicron sized polymeric particles were prepared by dispersion copolymerization of styrene with VBA‐PAspNa in a mixture of ethanol and water. Particle diameter decreased with increasing concentration and vinyl group fraction of VBA‐PAspNa. When compared with the particle diameter prepared using PAspNa or benzylamine‐modified PAspNa (BA‐PAspNa) as a dispersion stabilizer without vinyl groups, the particles prepared with VBA‐PAspNa were an order smaller than those prepared with PAspNa or BA‐PAspNa. The particles after refinement show an adequate negative ζ‐potential. From this result, we clarified the presence of PAspNa chains anchored onto the particle surface. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 762–770, 2009     

SiO2大分子单体的合成

SiO2大分子单体的合成;SiO2;甲苯二异氰酸酯;表面修饰;二氧化硅大分子单体     

Preparation of micron-size monodisperse polymer particles by dispersion copolymerization of styrene with poly(2-oxazoline) macromonomer

This article describes the preparation of micron-size monodisperse polymer particles by dispersion copolymerization of styrene with a poly(2-oxazoline) macromonomer in an aqueous ethanol solution. The macromonomer acted as a comonomer as well as a stabilizer. The diameter of the particles increased as the concentration of the macromonomer decreased. The higher the molecular weight of the macromonomer, the smaller the particle size. The copolymerization in the solvent containing higher water content gave smaller polymer particles. Under the condition giving the monodisperse particles, the particles volume increased linearly with the yield of the particles. From ESCA analysis of the particle surface, poly(2-oxazoline) chains were enriched on the surface. © 1993 John Wiley & Sons, Inc.     

侧链含炔丙基的PLGA-PEG-PLGA三嵌段共聚物的合成与表征

通过简单易行的技术路线合成了炔丙基化乙交酯单体,以1,4-二甲氨基吡啶为催化剂,亲水性和生物相容性良好的聚乙二醇为大分子引发剂,在较滥条件下引发炔丙基化乙交酯和丙交酯的开环共聚,制备了侧链含炔丙基的聚(乳酸-羟基乙酸)-聚乙二醇-聚(乳酸-羟基乙酸)(PLGA-PEG-PLGA)三嵌段共聚物,并对产物的组成与结构进行了表征.为生物孤犊触乳聚酯的分子修饰、生物相容性的提高探索一条简单而有效的途径     

Graft copolymers having hydrophobic backbone and hydrophilic branches. X. Preparation and properties of water-dispersible polyanionic microspheres having poly(methacrylic acid) branches on their surfaces

The free radical copolymerization of poly(t-butyl methacrylate) (PBMA) macromonomer with styrene in ethanol give monodispersed microspheres with 0.8-1.6 μm diameter. The resulting microspheres were treated with HCl solution to convert into anionic microspheres having poly(methacrylic acid) chains. ESCA analysis of the microsphere surface suggested that PBMA chains were favorably located on the surface of the microspheres. The particle size of the microspheres decreased with increasing molecular weight and concentration of the macromonomer. Water dispersibilities of the microspheres were evaluated by measuring the relative turbidity of the suspension of microspheres as a function of pH. The results show that they were strongly dependent on pH. © 1995 John Wiley & Sons, Inc.     

Preparation of polystyrene/silica nanocomposites by radical copolymerization of styrene with silica macromonomer

A two-stage process has been developed to generate the silica-based macromonomer through surface-modification of silica with polymerizable vinyl groups. The silica surfaces were treated with excess 2,4-toluene diisocynate (TDI), after which the residual isocyanate groups were converted into polymerizable vinyl groups by reaction with hydroxypropylacrylate (HPA). Thus, polystyrene/silica nanocomposites were prepared by conventional radical copolymerization of styrene with silica macromonomer. The main effecting factors, such as ratios of styrene to the macromonomer, together with polymerization time on the copolymerization were studied in detail. FTIR, DSC and TGA were utilized to characterize the nanocomposites. Experimental results revealed that the silica nanoparticles act as cross-linking points in the polystytene/silica nanocomposites, and the glass transition temperatures of the nanocomposites are higher than that of the corresponding pure polystyrene. The glass transition temperatures of nanocomposites increased with the increasing of silica contents, which were further ascertained by DSC.     

Preparation and Characterization of Polymeric Microspheres Having Isotactic Poly(methacrylic acid) on Their Surfaces

IntroductionUseful strategies for the synthesis of polymer-ic particles and their surface modification have re-ceived much attention. In recent years,authorshave been interested in the preparation and thecharacterization of sub- micron to micron- sizemonodisperse polymeric particles by the emulsifier-free radical dispersion copolymerization of hy-drophilic macromonomers and hydrophobicmonomers in polar solvents.Itwas found thatwa-ter- soluble polymer chains grafted on the surfacesof the partic…