巯基-烯光点击反应辅助合成多官能度蓖麻油基聚氨酯丙烯酸酯

研究巯基-烯光点击反应辅助合成多官能度蓖麻油基聚氨酯丙烯酸酯。首先通过光引发的巯基-烯点击反应,于蓖麻油分子上引入巯基乙醇,形成多羟基化合物,然后加入丙烯酸羟丙酯与异佛尔酮二异氰酸酯,以物质的量为1:1反应得到端异氰酸酯丙烯酸酯,最终得到蓖麻油基聚氨酯丙烯酸酯。通过调节羟基含量可以得到不同官能度的丙烯酸酯。采用红外光谱、核磁氢谱、热重分析等手段表征其结构和性能,并测试了合成的聚氨酯丙烯酸脂的吸水率、附着力等性能,同时考察了它的热稳定性。结果表明, 在紫外光照射下,巯基和不饱和双键之间发生了加成反应;该聚合物的固化膜性能得到提高,尤其是硬度和热稳定性。由本文快速合成方法得到的树脂性能良好,具有较好的应用前景,扩大了巯基-烯光点击反应在高性能UV固化材料方面的应用范围。     

光/潮气双重固化聚氨酯涂层的制备及性能研究

以甲苯-2,4-二异氰酸酯(TDI)和二乙醇胺(DEOA)为原料一步法合成了超支化聚氨酯,对其改性制备了光固化超支化聚氨酯丙烯酸酯(HPUA)和一系列双重固化(UV/潮气)超支化聚氨酯丙烯酸酯(DHPUA),使用傅立叶红外光谱(FT-IR)、核磁共振氢谱(1H-NMR)和碳谱(13C-NMR)以及凝胶色谱(GPC)对其分子结构进行了表征.并以其为预聚物制备光固化涂层,通过对双重固化涂层的表面形貌、热性能和物理性能的研究,结果表明,超支化双重固化涂层经过潮气固化后,涂层表面的粗糙度随着树脂中硅氧烷端基的含量的增加先下降后上升;超支化双重固化涂层的物理性能和热稳定性都随着树脂中硅氧烷端基的含量的增加而提升.     

Synthesis of a Novel Core-shell Type Acrylic-polyurethane Hybrid Emulsion Containing Siloxane and Fluorine as well as Water and the Oil Resistances of Cured Film

Aqueous acrylic-polyurethane dispersions have become one of the major types of materials used in coating, paint and adhesive industries, because of excellent properties and environmental advantages1-5. However, some properties for cured film such as water…     

Effects of biopitch on the properties of flexible polyurethane foams

Biopitches are industrial residues obtained by the distillation of the tar recovered during Eucalyptus charcoal production and can be used as a renewable polyol source. Flexible polyurethane foams were prepared with different proportions of biopitch and HTPB (hydroxyl-terminated polybutadiene) and using polymeric MDI (4,4′ diphenyl methane diisocyanate), N,N dimethylcyclohexylamine as a catalyst and water as a blowing agent. Elemental analysis, thermal analysis (TG/DSC), Fourier Transform Infrared Spectroscopy (FTIR), scanning electronic microscopy (SEM), and density results were used aiming to discuss the contribution of biopitch to foams properties. The higher the biopitch content, the higher the thermal stability and the lower the density of the flexible foams (air atmosphere), behaviors similar to those of lignin-based polyurethanes. Biopitch enhanced the oxygen content of the polyurethane foams synthesized, and their reaction with HTPB resulted in stable foams.     

Effect of monoacrylate type in UV curable PU acrylate based bicontinuous polymer/liquid crystal networks

Polymer network liquid crystals (PNLC) have been prepared from ultraviolet-curable polyurethane acrylate (PUA) and a nematic liquid crystal mixture (BL002). Effects of monoacrylate type on film morphology, temperature-dependent off-state transmittance, and electro-optic performance of the film have been studied. Among three types of monoacrylates incorporated (EHA(2-ethyl hexyl acrylate), MMA (methylmethacryalte), NVP (N-vinylpyrrolidone)), EHA-based PUAs gave the greatest polymer–LC phase separation, lowest threshold (V₁₀), and operating (V₉₀) voltages, and the effect was more pronounced in monoacrylate/triacrylate systems than in monoacrylate/diacrylate systems. Contact angle measurement offers a clue to the observed morphology and electro-optic behavior. © 1998 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 36: 1393–1399, 1998     

Graft copolymerization of hydroxyethyl cellulose with solketal acrylate: Preparation and characterization for moisture absorption application

In this work, we reported the preparation of a novel biomaterial, by graft-polymerization of 2-2-dimethyl-1-3-dioxolan-4-yl methyl acrylate (solketalacrylate, DMDMA) on hydroxyethyl cellulose (HEC) using KPS as initiator. Several experiments were performed to found the optimum conditions for the preparation of this biopolymer, by varying the time of the reaction as well as the initiator and the monomer ratio. Results showed that the highest grafting yield was 25%, obtained after 72?minutes at 65?°C, using THF as solvent. The structure of the grafted copolymer was confirmed by X-ray diffraction patterns which showed, besides the characteristic peaks of HEC at 2θ?=?31.74° and 44.63° a new peak at 2θ?=?30.72° related to an organized structure of the grafted polymer on the HEC backbone. The DSC analysis showed a single glass transition temperature Tg, intermediate between the corresponding values for HEC and neat poly(solketal acrylate). Moreover, the grafted biomaterial presented two-fold more moisture absorption ability by comparison with HEC, making this new synthetic biomaterial highly promising for dryness applications. In our knowledge, the synthesized monomer: 2-2-dimethyl-1-3-dioxolan-4-yl methyl acrylate, (solketal acrylate, DMDMA), has never been grafted on the HEC backbones before that is what makes the novelty of the present work.     

STUDY ON THE POLYMERIZATION KINETICS AND STABILITY OF P(UA)/MMA MICROEMULSION*

 Urethane acrylate anionomer (APUA) as a kind of new type polymerizable emulsifier was synthesized using 2,4-toluene diisocyanate (TDI), polypropylene glycol (PPG), 2-hydroxyethyl methacrylate (HEMA) and dimethylolpropionic acid (DMPA). The critical micelle concentration (CMC) of APUA was measured by the methods of conductance and surface tension. The comparative studies between polymerizable emulsifier AUPA and conventional emulsifier sodium dodecyl sulfate (SDS) were carried out in the emulsion polymerization of methyl methacrylate (MMA). Polymerization kinetics,stability, size and morphology of the latex particles were investigated. It was found that in APUA both water soluble initiator potassium persulfate (KPS) and oil soluble initiator 2,2'-azobisisobutyronitrile (AIBN) can start the reaction of MMA, and the polymerization rate and yield were very high. On using AIBN as an initiator, the conversion-time behavior of MMA with APUA as emulsifier was different to that of SDS as emulsifier, signifying a different nucleation mechanism of the polymer latex particle. The average size of the two kinds of particles is about 50 nm. The particle size decreases with increasing emulsifier concentration. On using KPS as the initiator, APUA as emulsifier, cross-linking hydrogel of PMMA would be formed, but SDS was used as emulsifier and the hydrogel of PMMA was not present.     

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     

Synthesis of a fluoro-diol and preparation of fluorinated waterborne polyurethanes with high elongation at break

In this study, a fluoro-diol, trifluoroethyl-2-methylpropanoate-β-dihydroxy ethylamine (TFMDA), was successfully synthesized by Michael Addition reaction between trifluoroethyl-2-methacrylate (TFEMA) and diethanolamine (DEA). The chemical structures were characterized by FT-IR and ¹H NMR methods. And then by the reaction of dicyclohexylmethylmethane-4,4′- diisocyanate (HMDI), poly(propylene glycol) (PPG), 2,2-dimethylolbutanoic acid (DMBA), diethylene glycol (DEG) and trifluoroethyl-2-methylpropanoate-β-dihydroxyethylamine (TFMDA), fluorinated waterborne polyurethane emulsions with different content of COOH and TFMDA were successfully prepared. It was demonstrated that all the polyurethane emulsions exhibited enhanced storage stability and all the polyurethane films possessed high elongation at break and exceeded 1000%. Addition of organic fluorine obviously improved the water-resistance property of the waterborne polyurethane films.     

硅氧烷改性水性聚氨酯的制备及性能

A series of novel aqueous emulsion of siloxane modified polyurethane (PU(PE-PSI)) were synthesized based on poly(propylene glycol) (PPG), polyether-grafted polysiloxane (PE PSI), 2,4-tolylene diisocyanate (TDI), dimethylol propionic acid (DMPA) and 1,4 butanediol (BDO) through a direct water emulsification of triethylamine (TEA). The aqueous emulsion was transparent and had a good stability. Fourier transform infrared spectroscopy (FTIR) was used to identify the structure of PU (PE PSI), indicating that the polysiloxane segment had been incorporated with polyurethane chain. Investigation of Electron Spectroscopy for Chemical Analysis (ESCA) and the water contact angle demonstrated that the siloxane migrated to the surface of film. The results also showed that PU(PE-PSI) was still a very good elastomer. With increasing the content of PE PSI, the resistance to water improved and tensile strength increased, while the ultimate elongation decreased slightly for the PU(PE-PSI) film.     

Polyaddition reaction in a dispersed medium: elaboration of new core-shell polyurethane particles

The elaboration in a dispersed organic medium of calibrated polyurethane particles with a core-shell structure is presented in this paper. The objective could be achieved by using a series of reactive steric stabilizers of the type ω-(OH)_x-poly(n-butyl acrylate), -polystyrene, -polysiloxane or -polybutadiene (x=1 or 2) that play the role of surfmers during the polyaddition reaction between ethylene glycol and tolylene-2,4-diisocyanate, in cyclohexane as a dispersant medium. The final size of the polyurethane particles (0,5-10 μm) was found to be a function of the steric stabilizer characteristics (nature, molar mass and concentration) and of the addition procedure of the different reactants. These novel particles constituted of a polyurethane core and various shells depending on the stabilizer used exhibit specific and original properties.     

Studies on the Preparation of Stable and High Solid Content Emulsifier-Free Poly(MMA/BA/HEA) Latex with the Addition of AMPS and Characterization of the Obtained Copolymers

The 2-acrylamido -2-methylpropane sulfonic acid (AMPS) was used as a reactive comonomer for the methyl methacrylate (MMA), n-butyl acrylate (BA) and 2-hydroxyethyl acrylate (HEA) emulsifier-free emulsion copolymerization system to obtain latices of stable and high-solid content (50 wt%).The polymerization and storage process is very stable, and the emulsion could store at room temperature for more than six months with the addition of AMPS. Properties of the latices, such as stability, flow behavior, particles diameter and morphology were studied. In addition, physical properties of the obtained copolymers, such as water resistance, glass transition temperature (T_g) were also investigated. The final size of the latex particles is 200～300 nm in diameter. Compared with the copolymers that were prepared by surfactant emulsion polymerization water resistance is greatly improved.     

Effect of different surfactants on colloidal and polymer properties of fluorinated acrylate latex

Fluorinated acrylate latex was successfully prepared by semi-continuous seeded emulsion polymerization of dodecafluoroheptyl methacrylate (DFMA) with butyl acrylate (BA), methyl methacrylate (MMA) initiated by potassium persulfate in the water. The resultant latexes and their films are characterized with Fourier transform infrared (FTIR) spectrometry, contact angle determinator, dynamic light scattering detector and surface tension determinator. Effect of different surfactants on colloidal and polymer properties of fluorinated acrylate latex was studied. Results show that the latex prepared with sodium dodecyl benzene sulfonate surfactant has the smallest particle size and contact angle but the moderate surface tension. The latex prepared with perfluorooctanesulfonic acid potassium surfactant has the smallest surface tension, moderate particle size but the biggest contact angle. The latex prepared with sodium 2-hydroxy-3-(methacryloyloxy) prop- ane-1-sulfonate surfactant has the biggest particle size and surface tension but moderate contact angle. In addition, the latex prepared with sodium 2-hydroxy-3-(methacryloyloxy) prop- ane-1-sulfonate has higher electrolyte stability.     

丁羟胶型聚氨酯弹性体的水解稳定性

丁羟胶型聚氨酯弹性体的水解稳定性;弹性体;扩链剂     

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     

离子型共聚单体参与下的全氟丙烯酸酯无皂乳液共聚

离子型共聚单体参与下的全氟丙烯酸酯无皂乳液共聚;全氟烷基丙烯酸酯;无皂乳液;离子型共聚单体     

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)...     

Influence of the composition on the glass transition temperature of polyurethane and polyurethane acrylate networks

Linear polyurethane, linear segmented polyurethane, polyurethane networks, and polyurethane acrylate networks of various composition were synthesized. The variation of T_g with the type of macrodiol, its length, and the chemical composition of the polymer were studied in relation with the percentage of soft segments, the molar mass between crosslinks, and the concentration of urethane bonds. In this work, the networks were considered as composed of chain segments of various composition between point-like crosslinks. The chemical heterogeneities of the networks were not taken into account. For polyurethanes, it was shown that T_g values are essentially controlled by the amount of urethane bonds. For polyurethane acrylates, the T_g values are dependent on the amount of urethane bonds but also on the presence of crosslinks whose number is varying with the excess of diisocyanate of the first step three times faster for PUA compared with PU. No clear relation was observed between T_g and the molar mass between point-like crosslinks. Another approach considering the network heterogeneities is indispensable and will be used in a following work. © 1996 John Wiley & Sons, Inc.     

含氟丙烯酸酯三元共聚物乳液的研究

以丙烯酸全氟烷基酯 (ZonylTM)、甲基丙烯酸甲酯 (MMA)、丙烯酸丁酯 (BA)为原料 ,在阴离子乳化体系中制备了含氟丙烯酸三元共聚物乳液 .研究了聚合反应动力学、转化率的各种影响因素 ,得出了聚合速率方程 ,并得出反应的表观活化能 (Ea)为 5 0 75 8kJ mol.考察了乳液的稀释稳定性、贮存稳定性、离心稳定性、耐热、耐寒稳定性 ,及乳胶膜的吸水性和耐溶剂性 .并用Wilhelmy方法测定了乳胶膜与水的接触角 ,结果表明乳胶膜对水的抗浸润力大大提高     

Synthesis and photochemical reaction of novel p-alkylcalix[6]arene derivatives containing acryloyl or methacryloyl groups

Novel polyfunctional (meth)acrylates with a calixarene backbone [calixarene (meth)acrylates] were synthesized in good yields by certain reactions of p-methylcalix[6]arene (1a) or p-tert-butylcalix[6]arene (1b) with (meth)acrylate derivatives such as acryloyl chloride, methacryloyl chloride, (2-methacryloxy)ethyl isocyanate, and glycidyl methacrylate. Polyfunctional acrylate 6a having poly(oxyethylene) spacer chain between 1a and acrylate groups was also synthesized by the reaction of the poly(oxyethylene) modified 1a with acrylic acid. Calixarene acrylate 6a was liquid at room temperature, although the other calixarene (meth)acrylates were solid at room temperature. The initial decomposition temperature (IDT) of the resulting calixarene (meth)acrylates was measured by the thermogravimetric analysis to evaluate the thermal stability, and it was found that some of the IDTs of the calixarene acrylates were over 400°C. This means that calixarene (meth)acrylates have very good thermal stability. The photopolymerization of the resulting some calixarene (meth)acrylates with (2-phenyoxy)ethyl acrylate as a reactive diluent in the presence of photoinitiator proceeded smoothly upon irradiation with UV light. Therefore, polyfunctional (meth)acrylates with a calixarene backbone can be expected to be novel and thermally stable photoreactive acrylate oligomers. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 3071–3078, 1999