Preparation of UV curable emulsions using PEG-modified urethane acrylates and their coating properties III: Effects of epoxy acrylate

Water-dispersible UV-curable urethane acrylate emulsions were prepared with polyethylene glycol (PEG)-modified urethane acrylates (PMUA), containing terminal hydrophilic polyoxyethylene chains. To improve physical properties of PMUA, epoxy acrylate (EA) having high thermal stability and hardness, was mixed with five kinds of PMUA containing different chain lengths of polyoxyethylene (POE). For PMUA/EA mixtures, the composition ratio of EA to PMUA and the chain length of POE greatly influenced the size of droplets of emulsions and the physical properties of their cured films. At higher EA to PMUA ratio, the physical properties decreased, which was due to phase separation between EA and PMUA. Phase separation was confirmed by scanning electron microscopy. Received: 13 September 1996/Revised: 27 November 1996/2 December 1996     

Preparation of UV-curable PEG-modified urethane acrylate emulsions and their coating properties. II. Effect of chain length of polyoxyethylene

To prepare self-emulsifiable urethane acrylate, poly(ethylene glycol)-modified urethane acrylates (PMUA), containing polyoxyethylene chains as a terminal group were synthesized by the reaction of a residual isocyanate group with poly(ethylene glycol) (PEG). Five types of PMUA were synthesized using five types of PEG having different molecular weight. As the chain length of polyoxyethylene of PMUA increased, the thermal stability of their emulsions improved and the tensile strength of their UV-cured films were also increased. For PMUA600 prepared using PEG600, the thermal stability of the emulsion and tensile strength of UV-cured film were relatively low. However, the emulsions of PMUAs which were synthesized using PEG2000, PEG4000, and PEG6000 were stable with increasing temperature and the tensile strength of their cured films was greater than that of PMUA 600. When PMUA600 was mixed with PMUA2000, PMUA4000, and PMUA6000, the thermal stability of the emulsions of mechanical properties of their UV-cured films were improved greatly. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 2657–2664, 1997     

Preparation of hyperbranched polyester polyol-based urethane acrylates and applications on UV-curable wood coatings

In the present study, hyperbranched urethane acrylates (UA/HB-PEs) were synthesized by modifying the hydroxyl groups of hyperbranched polyester polyols (HB-PEs). The structure of oligomers were characterized by FTIR and ¹H NMR spectroscopic techniques. Formulations containing UA/HB-PEs, reactive diluents, and photoinitiator were applied onto wood substrates and successfully polymerized under UV-irradiation. The coating performances and thermal properties of UV-cured films were evaluated. The studies on film characteristics reveal that the incorporation of UA/HB-PE afforded coatings with good adhesion and high gloss properties. It is observed that UV-cured coatings originated from [2,2-bis(4-??-hydroxyethoxy) phenyl propane] (HB-HEPA)- and [2,2-bis(4-??-hydroxyethoxy) phenyl 6F propane] (HB-HEPFA)-based oligomers possessed better surface and mechanical properties.     

Preparation and properties of UV-curable polyurethane acrylates

UV-curable polyurethane (PU) acrylates have been synthesized from polypropylene glycol (PPG), isophoron diisocyanate (IPDI), and three types of reactive diluents, i.e., 2-hydroxyethylacrylate (HEA), tripropyleneglycol diacrylate (TPGDA), and trimethylolpropane triacrylate (TMPTA). The effects of soft segment length, type, and concentration of reactive diluent on the mechanical and dynamic mechanical properties have been determined. When the soft segment length was short (750) tensile strength (σ_b) decreased, and elongation at break (ϵ_b) generally increased with increasing HEA concentration, due respectively to the inferior strength of HEA homopolymer, and increased molecular weight between crosslinks (M_c). Initial modulus (E) and σ_b increase and elongation at break (ϵ_b) decreased with the increase of TPGDA concentration, and the effect was more pronounced as the soft segment length decreased. The hardness and σ_b increase with diluent concentration in PPG 2000-based materials was more pronounced with higher functionality diluent, due to the increased crosslinking density. The lower temperature glass transition peak of PU was not influenced by the TPGDA incorporation, whereas the higher temperature one moved toward still higher temperature. This was interpreted in terms of possible compatibility of hard segments and acrylates due to their similar polarity and hydrogen bonding. © 1996 John Wiley & Sons, Inc.     

Preparation and properties of UV-curable polydimethylsiloxane urethane acrylate

A new type of a UV-curable polyurethane acrylate resin based on hydroxyterminated polydimethylsiloxane (PDMS) soft segments with molecular weight 1800 and 2,4-toluene diisocyanate (TDI)/2-hydroxyethyl methacrylate (HEMA) hard segments were synthesized. The reactivity of 2,4-TDI with the hydroxy groups of silanol and HEMA was discussed by means of IR measurements. The characteristic absorption peaks of the —NCO groups of 2,4-TDI in the para- and ortho-position should decline with increasing the reaction time. The measurements of fundamental physical properties of this type of UV-curable materials had been widely studied in addition to the effects of using various reactive diluents and some pigments. This kind of resin with good optical, electrical insulating, and adhesive properties on various matrices, could be improved in chemical properties and reduced in viscosity while promoting the coating processability by mixing with various reactive diluents. The excellent adhesive properties on glass plates can be attributed to the similar structure between the PDMS soft segments and glass which makes the application in the coating industry possible.     

阴离子改性PUA紫外光固化胶粘剂的制备及性能

以异佛尔酮二异氰酸酯(IPDI)、二羟甲基丁酸(DMBA)和聚四氢呋喃醚二醇(PTMG)等为主要原料,制得聚氨酯(PU)预聚体;然后将其与丙烯酸羟乙酯(HEA)反应,制得HEA封端的聚氨酯丙烯酸酯(PUA)预聚体;最后在PUA预聚体中加入中和剂等助剂,制备出阴离子改性PUA紫外光(UV)固化胶粘剂。研究结果表明:当w(DMBA中-COOH)=1.2%(相对于PU预聚体质量而言)、中和度=n(中和剂)∶n(DMBA)=80%、以PTMG为多元醇且偶联剂采用预处理法加入时,相应的阴离子改性PUA型UV固化胶粘剂的耐水性、粘接强度和耐久性俱佳。     

聚氨酯丙烯酸酯体系PDLC膜的制备及性能研究

本文以聚氨酯丙烯酸酯为预聚物,使用甲基丙烯酸十八烷基酯、甲基丙烯酸月桂酯、丙烯酸二甲基氨基乙酯、丙烯酸丁酯等作为稀释剂,通过相分离的方法将液晶和聚合物混合后,在紫外光的照射下,制备聚合物分散液晶膜。并在此方法下,探索了不同稀释剂单体、不同含量预聚物、液晶、光引发剂等混合的条件下所制备的PDLC材料性能。     

Preparation and evaluation of nonionic amphiphilic phenolic biocides in urethane hydrogels

Phenols are rarely used in the preparation of polyurethanes because of the inherent competitive reaction of the phenolic moiety with isocyanates. This work represents a successful application of the combination of phenols with isocyanates toward the development of phenolic‐based antimicrobial urethane coatings for niche applications. In this effort, a series of nonionic amphiphilic phenolic molecules were prepared by condensation of 4‐hexylresorcinol with the corresponding hydroxyl‐terminated monomethyl poly(ethylene glycol) in the presence of a catalytic amount of acid in refluxing toluene. These new molecules were evaluated against a variety of Gram‐positive and Gram‐negative bacteria for their antimicrobial activity in minimum inhibitory concentration solution testing. The same amphiphilic molecules were also incorporated into a hydrophilic polyurethane hydrogel and dispensed as films for evaluation of surface activity with a newly developed protocol. All samples possessed some degree of surface antimicrobial activity, which was expressed as a log kill reduction in colony‐forming units starting from an initial bacterial concentration of 10⁷ CFU, and structural features of the phenolic compound were found to contribute significantly to the observed antimicrobial activity. The highest activity was observed in samples containing the phenolic compound with the shortest ethylene oxide polar structural feature and therefore highest mobility in the highly polar urethane resin. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Properties of UV-curable polyurethane acrylates using nonyellowing polyisocyanate for floor coating

UV-curable polyurethane acrylates for poly(vinyl chloride) (PVC) floor coating were prepared using nonyellowing polyisocyanates. The effects of the chemical structure of the polyisocyanates and hydroxyacrylates, and the compositions of the prepolymer/diluent on the properties of the UV-curable polyurethane acrylates were investigated. Several different urethane acrylate prepolymers from four different polyisocyanates, isophorone diisocyanate (IPDI) adduct, hexamethylene diisocyanate (HDI) adduct, HDI biuret, and HDI isocyanurate, and two different hydroxyacrylates, hydroxyapropyl acrylate (HPA), polycaprolactone modified hydroxyethylhexylacrylate (PCMHEA). UV-curable coating materials were formulated from the prepolymers and 1-hydroxycyclohexylphenyl ketone as a photoinitiator with polyethylene glycol diacrylate (PEGDA) as a diluent. The polyurethane acrylates prepared with HDI isocyanurate and the equimolar mixture of HPA and PCMHEA showed balanced coating properties such as tensile properties, hardness, weatherability, and good adhesion. The dynamic mechanical studies showed the properties of those polyurethane acrylates were well correlated with their glass transition temperature behaviors. It was also found that the adhesion was best as a PVC floor coating with the appropriate viscosity (below 150 P at 25°C) when 35% PEGDA as a diluent was used. © 1996 John Wiley & Sons, Inc.     

阴离子/非离子表面活性剂协同效应研究

研究了脂肪酸甲酯磺酸钠(MES)与脂肪醇聚氧乙烯醚(AEO9)复配体系在298 K、318 K下的表面化学性质,计算了二者在混合胶束及混合吸附层中的协同作用参数,进而得知混合胶束及混合吸附层中二者的组成情况。结果显示,复配体系的表面化学性能明显优于单一体系,复配体系无论在混合吸附层或混合胶束中均显示出强烈的协同作用。     

Preparation and characterization of UV-curable urethane acrylate oligomers modified with cycloaliphatic epoxide resin

The UV-curable urethane acrylate oligomers modified with cycloaliphatic epoxide resin, including polyether-modified cycloaliphatic polyurethane acrylate (CE-MP-UA) and oleic acid-modified cycloaliphatic polyurethane acrylate (CE-OA-UA), have successfully been synthesized and characterized by ¹HNMR and FTIR. The kinetics of the synthesis processes are studied in this paper. The effects of the molecular structure of the oligomers on the properties of cured film, including pencil hardness, impact resistance, adhesion and boiling water resistance, are discussed in detail. The experimental results indicate that the films formed by CE-OA-MP oligomers show good comprehensive performance, especially good adhesion and boiling water resistance due to the numerous hydroxyl groups, flexible segment and alicyclic structure of the oligomers. The results reveal that the alicyclic structure in the oligomer molecular make-up can effectively improve the adhesion of UV-curable coatings.     

非离子水性环氧树脂乳化剂及其乳液的制备与性能研究

以EP(环氧树脂)、PEG(聚乙二醇)、邻苯二甲酸酐为原料,合成了一种非离子反应型水性EP乳化剂,并通过相反转法制备了稳定的水性EP乳液,对酯化反应条件进行了优化,并探讨了PEG分子量、乳化剂用量、相反转条件对乳液性能的影响。研究结果表明:在温度110℃、时间2.5 h下能较好控制酯化过程,红外光谱和GPC分析结果表明得到了预期结构的乳化剂;选择基于PEG-6000合成的乳化剂,在乳化剂用量为15.0%、相反转条件为60℃、转速2 500 rpm时获得的水性EP乳液具备良好的稳定性。     

Smectites as colloidal stabilizers of emulsions: I. Preparation and properties of emulsions with smectites and nonionic surfactants

Bentonites, montmorillonites, and hectorites were used as colloidal stabilizers of oil-in-water (O/W) emulsions. The enrichment of the solid particles on the oil–water interface was attained by the addition of nonionic coemulsifiers (glycerol monostearate (GMS), deca(ethylene glycol) hexadecyl ether, alkyl polyglucoside, and lecithin). The clay mineral content of the aqueous dispersion was 2% (w/w). Stable emulsions required amounts of 0.5–1.5 g coemulsifier per 100 ml aqueous dispersion. Oil volume fraction was varied between φ=0.17 and φ=0.50. At φ>0.50 the O/W emulsions changed into water-in-oil (W/O) emulsions. The number average diameter of the droplets was about 25 nm. The volume average diameter (50–100 nm) more strongly depended on the clay mineral/coemulsifier combinations. Wyoming bentonite and the corresponding delaminated sodium montmorillonite were useful stabilizers; technical, soda-activated bentonites yielded unstable emulsions, or emulsification was not successful. A synthetic hectorite which caused pronounced thickening of the coherent phase was an effective stabilizer. Creaming was often observed because of the buoyancy of the large droplets. Most of the creamed emulsions were stable over long periods and did not separate an oil phase. The resistance against creaming increased with the oil volume fraction. An increase of the solid content had to be accompanied by an increase of the coemulsifier concentration to reduce the rate of creaming.     

阴离子多聚糖修饰Pickering乳液的制备及表征

为了提高淀粉纳米晶(SNC)与季铵盐壳聚糖(QCS)共同稳定的Pickering乳液在p H变化时的稳定性,以阴离子多聚糖海藻酸钠和果胶为原料,通过静电作用对乳液进行表面修饰,制得两种Pickering乳液。通过测定乳液粒径、Zeta电位和体外消化情况,对乳液的稳定性和消化特性进行了表征。结果显示:当水相中海藻酸钠和果胶质量分数均为0.1%(以水相为基准)时,修饰后的两种Pickering乳液在p H=2~7内均能保持粒径不变,且该乳液在25℃下放置90 d,粒径无变化,无乳析现象发生。此外,在体外模拟消化条件下,阴离子多聚糖的加入还能抑制Pickering乳液中油脂和淀粉的消化。     

Properties of UV-curable polyurethane acrylates: Effect of reactive diluent

Several families of UV-cured polyurethane acrylates were synthesized, and the effects of reactive diluent type and content on their physical properties were investigated. Increasing reactive diluent content promoted the development of a second, high glass transition temperature phase in all the materials, thereby leading to increased strength and modulus. Changes in the extensibility of the samples upon addition of reactive diluent were inversely related to the effect of the diluent on the crosslink density. The effects of using different reactive diluents (di-, tri-, and tetraethylene glycol diacrylate and N-vinyl pyrrolidone) on the physical properties of the samples were attributed to differences in the softening point (T_g) of the homopolymer reactive diluents and the relative compatibility of the reactive diluents with the urethane acrylate segments.     

Preparation of toughened PMMA through PEG-modified urethane acrylate/PMMA core–shell composite particles

Poly(urethane acrylate) (PUA)/poly(methylmethacrylate) (PMMA) core–shell composite particles were prepared by two-stage emulsion polymerization. The sizes of composite particles could be varied from 25 to 210 nm by introducing polyoxyethylene (POE) groups to the urethane acrylate molecular backbone. Core–shell morphology was identified by investigating the polarity of the surface of the core and shell polymer particles and by measuring the contact angle of the composite particles. A composite particle prepared with relatively small particles (about 20 nm) did not show the core/shell morphology, because the high polar surface of the core polymer particle and the low-stage ratio of the core to the shell cause the formation of a core/shell two-stage latex to be more thermodynamically unstable. The fracture toughness of rubber-toughened PMMA containing PUA/PMMA composite particles increased as the particle sizes decreased and the shell thickness of the composite particles increased. In particular, when the average size of the composite particle was about 43 nm and the stage ratio was 50/50, the fracture toughness of the rubber-toughened PMMA increased more than three times compared with that of pure PMMA. Furthermore, the transparency of toughened PMMA could be maintained up to 91% in the visible spectra range. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 2291–2302, 1998     

氨基甲酸酯基丙烯酸酯的合成及其光固化性能

利用碳酸亚乙酯与1,6-己二胺、异佛尔酮二胺反应，制备出两种含氨基甲酸酯基的二元醇，基于氨基甲酸酯二元醇与1,6-己二醇二丙烯酸酯（HDDA）、新戊二醇二丙烯酸酯（NPGDA）及三羟甲基丙烷三丙烯酸酯（TMPTA）本体条件下的Oxa-Michael加成反应及酯交换反应，合成出6种含氨基甲酸酯基的丙烯酸酯混合物。利用FTIR及高分辨质谱分析了产物结构，用FTIR考察了所合成氨基甲酸酯基丙烯酸酯光固化过程的动力学,测定了光固化膜的性能。结果表明，在含占总质量分数3% 的2-羟基-2-甲基-1-苯基-1-丙酮（1173）光引发剂的引发下，氨基甲酸酯基丙烯酸酯能在30s内固化形成表面平整、柔韧性（0.5~2.5mm）良好、透明或半透明的膜；固化膜的凝胶率及铅笔硬度分别为92%~96%、4~5H，对玻璃的附着力为0~1级。     

Mechanical and thermal properties of UV-curable polyurethane and polyurea acrylates

Soft-segment molecular weight, soft-segment crystallization, hard-segment-type, and reactive diluent level were examined in urea and urethane acrylates. Increasing soft-segment molecular weight led to a decreased tensile modulus, increased strength, and increased elongation at break. Soft-segment crystallization increased the modulus below the melting temperature, but decreased the modulus above the melting temperature because crystallization interfered with cross-linking. Materials with hard segments that allowed for greater phase separation showed a higher modulus, higher ultimate stress, and higher ultimate elongation. Materials with reactive diluents 2-hydroxyethyl methacrylate (HEMA) and N-vinyl pyrrolidinone (NVP) showed qualitatively different behavior. HEMA caused the modulus and strength to increase with little effect on elongation up to concentrations of 50 wt %; at higher concentrations, the elongation decreased. NVP also increased the modulus and strength; however, at 40 wt % NVP, ultimate elongation increased in a well-phaseseparated system and decreased in a poorly phase-separated system. In tensile tests, samples with 40% NVP also showed substantial sample necking and drawing. © 1993 John Wiley & Sons, Inc.     

Reactive diluents and properties of ultraviolet-cured polycarbonate urethane acrylates

Polymer films obtained from photocurable formulations were investigated by tensile methods and dynamic mechanical analysis. The polymer formulations contained photoinitiator, urethane diacrylate oligomer, and acrylic reactive diluent. It was found that diluent concentration may strongly affect the glass transition temperature and elastic modulus of the cured coating. When the diluent homopolymer glass transition temperature is larger than that of oligomer homopolymer, the glass transition temperature and elastic modulus of the coating film increase with the increase of the diluent concentration. When the diluent homopolymer has lower glass transition temperature than the homopolymer of the oligomer, the increase in diluent concentration leads to a decrease in glass transition temperature and elastic modulus of the UV-cured coating film. The effect of the testing temperature on tensile storage modulus of the films containing different concentrations of reactive diluents was studied as well. The data indicated that a variety of coatings with wide ranging but predictable properties can be formulated from previously examined starting materials but used at different concentrations. © 1995 John Wiley & Sons, Inc.     

Making homogeneous and fine droplet O/W emulsions using nonionic surfactants

In many emulsion systems, creaming occurs during the first stage of emulsion breakdown. To reduce the rate of creaming, emulsions having small and uniform droplets are desirable. In this work, types and HLB of nonionic surfactants, emulsification methods, and combinations of oils and nonionic surfactants were investigated in order to make stable and homogeneous emulsions. Emulsification was attained by dissolving the surfactants in the oil phases. The addition speed and volume of water to the oil phases were important factors affecting the emulsion droplet size. The change of the solute state in the process of emulsification was observed stage by stage, and the mechanism of emulsification was elucidated. Homogeneous emulsions were formed in the HLB region, showing liquid crystalline and gel phases in the emulsifying process. The addition speed of water to the oil phase was very important in forming the liquid crystalline and gel phases. Polyoxyethylene(n)sorbitan monostearate could emulsify three kinds of oils (hydrocarbon, fatty acid ester and triglyceride). Polyoxyethylene(n)alkyl ether could emulsify hydrocarbon and fatty acid ester. Polyoxyethylene(n)-monostearate could emulsify only hydrocarbon. Surfactants with proper HLB which were soluble in the oil phase and in the presence of a very small amount of water formed a stable emulsion. The solubility state of oil and surfactant was the key to making a fine emulsion.