紫外光固化环氧聚硅氧烷树脂的制备与性能

以1,2-环氧-9-癸烯和双侧氢封端的聚二甲基硅氧烷为反应物,在卡斯特催化剂〔铂(0)-1,3-二乙烯-1,1,3,3-四甲基二硅氧烷〕的催化下发生硅氢加成反应,成功制备了环氧基聚硅氧烷预聚物,并使用阳离子型光引发剂对其进行紫外光固化,制得紫外光固化环氧聚硅氧烷树脂。对合成双端环氧基聚硅氧烷预聚物的反应条件进行优化。利用FTIR和1HNMR对所合成预聚物的结构进行了结构表征,采用热失重分析、差示扫描量热法、接触角、耐碱性、耐醇性、凝胶率、邵氏A硬度和断裂面微观形貌对固化膜的性能和形貌进行了测试。结果表明：在反应温度为75 ℃、催化剂有效成分添加量为0.009‰（以双端含氢聚硅氧烷和1,2-环氧-9-癸烯的质量和为基准,下同）条件下,8 h时反应程度达93.95%;当使用光引发剂BL9380用量为3%（以预聚体质量为基准,下同）、固化时间为20 s时,制得的树脂表面活性能为18.4~18.8 mN/m,耐碱性、耐醇性良好,凝胶率为93.9%,邵氏A硬度为37,空气气氛下两个最大分解速率分别为437.6和511.3 ℃,780 ℃下质量残余率为13.9%,固化膜的综合性能最好。     

UV-curable epoxy varnishes modified with polyvinyl resins

Epoxy varnishes based on 3,4-epoxycyclohexylmethyl-3′,4′-epoxycyclohexanecarboxylate (EEC) and polyvinyl components, i.e., two polyvinyl butyral resins (PVB) and one polyvinyl butyral-stat-acetal resin (PVBA) were prepared and cured using a commercial cationic iodonium photoinitiator and medium-pressure mercury lamp. An influence of a type and content of polyvinyl resin (5, 10, and 20 wt.%) on thermal, optical, mechanical, and barrier features of varnish coatings was investigated. Coats containing the highest amount of PVB resins exhibited higher epoxy group conversion, higher gloss, and smoother surface in comparison with EEC/PVBA samples. Moreover, cured coats and films with PVB reached markedly higher barrier features, i.e., limited distilled water absorption and low water vapor transmission rate. An influence of reactivity and UV transmittance value of the photocurable varnishes on coat wrinkling process was presented and discussed.     

UV-curable acrylic resins for production of glass laminates

Glass laminates have been readily obtained by photocuring at ambient temperature of an acrylic adhesive consisting either of a liquid resin or a solid thermoplastic polymer. The light-induced polymerization process was followed by real-time infrared spectroscopy. Close to 100% conversion was reached within a few seconds of exposure, by taking as the photoinitiator an α-hydroxy alkylphenone or an aryl phosphine oxide. A liquid formulation containing an aliphatic polyurethane–acrylate oligomer, acrylic acid, and butyl acrylate gives the best performance in terms of reactivity, adhesion, impact resistance, and transparency. The impact resistance was further increased by introducing a polycarbonate core between the two glass plates. The solid thermoplastic polymer was obtained either by casting from a solution containing an aliphatic polyurethane, an acrylate oligomer, and the photoinitiator or by mixing these compounds in the molten state and further extrusion. The glass assembly was heated above the softening temperature (80°C) under a 1 MPa pressure and cured by a 1 min exposure to UV radiation to give a strongly adhesive laminate showing good transparency and long term weatherability. © 1995 John Wiley & Sons, Inc.     

Hydrophilic UV-curable PU resins for PET micro-fiber applications

Hydrophilic UV-curable PU oligomers (UV-PU) were prepared by mixing either the toluene diisocyanates (TDI) with polyethylene glycol-1000, or the isophorone diisocyanate (IPDI) with polypropylene glycol-1000 and dimethylol propanic acid (DMPA), to produce the desired carboxylic acid bearing or non-ionic PU oligmer (NCO-PU), separately. The 2-hydroxyethyl methacrylate (HEMA) was then added into the NCO-PU oligomer to form acrylate-terminated (UV-curable) PU oligomer (UV-PU). The reactive diluents, such as 1,6-hexanediol diacrylate (HDDA), trimethylolpropane tricarylate (TMPTA) and others were used to adjust the viscosity of UV-PU and to control the concentration of acrylic group. The hydrophilic UV-curable PU system was formulated and applied on PET micro-fiber and then cured by an UV-radiation at ambient temperature. The physical, thermal, and mechanical properties, in particular, the hydrophilic properties of UV-curable PU treated PET micro-fibers will be discussed.     

UV固化水性聚氨酯丙烯酸酯的合成与性能

以异佛尔酮二异氰酸酯(IPDI)、聚醚二元醇(DL-1000)、二羟甲基丙酸(DMPA)和甲基丙烯酸羟乙酯(HEMA)为主要原料合成了具有感光性能的水性聚氨酯丙烯酸酯(PUA)乳液,通过红外光谱对其结构进行了表征。其与活性稀释剂二缩三丙二醇二丙烯酸酯(TPGDA)、光引发剂混合均匀得到水性紫外光(UV)固化树脂。通过涂膜性能测试,研究了各配方组分、UV固化条件等对涂膜性能的影响。结果表明:适宜的DMPA质量分数为5.5%～6.0%,NCO/OH物质的量比为1.55∶1,TPGDA质量分数为10%,光引发剂为TPO,其用量为总树脂质量的4%,光照时间为7.0 s,以其制得的PUA树脂外观、贮存稳定性和耐黄变性良好,涂膜的综合性能最佳。     

Boron containing UV-curable epoxy acrylate coatings

In the present work boron acrylate monomer was synthesized by esterification reaction. UV-curable boron containing epoxy acrylate coatings were prepared and applied on plexiglass substrates to obtain thermally and mechanically stable coatings. The physical and mechanical properties of UV-cured coatings were investigated such as gel content, solvent resistance, hardness, flexibility and tensile tests. The thermal behavior of coatings was also evaluated. It was observed that the tensile properties and thermal stabilities of boron modified epoxy coatings mainly depend on the boron content.     

Analysis of lipids containing hydroxy fatty acids

Lipids containing hydroxy fatty acids or hydroxyacyl moieties are acetylated with [1-¹⁴C]acetic anhydride or [³H]acetic anhydride, and the content of hydroxy fatty acids or hydroxyacyl moieties is estimated from the specific radioactivity of the acetylated products with respect to that of radioactive standards, such as radioacetylated ricinoleic acid or triricinoleoylglycerol. Mixtures of triacylglycerols containing one, two and three hydroxyl groups per molecule are derivatized in a similar manner, and the resulting acetates are fractionated by thin layer chromatography according to the number of acetate groups per molecule. The relative proportion of each type of triacylglycerols in the mixture is estimated from the distribution of radioactivity in the various fractions. Applications of these techniques are demonstrated by the analysis of several seed lipids.     

Synthesis of bio-based unsaturated polyester resins and their application in waterborne UV-curable coatings

In this paper, three bio-based unsaturated polyesters were synthesized from itaconic acid and different diols which could be derived from renewable resources. Their chemical structures were confirmed by FT-IR, ¹H NMR and acid value as well as hydroxyl value. Waterborne UV curable networks based on these polyesters were manufactured and their mechanical properties, thermal stability and coating properties including pencil hardness, flexibility, adhesion, water resistance and solvent resistance were investigated. Results showed that the UV-cured polyester coatings exhibited high hardness, good water resistance and solvent resistance. The coatings reported in this paper combined the merits of bio-based materials, UV-curing process and water distribution.     

Effects of nonreactive resins on the properties of a UV-curable methacrylated urethane resin

The effects of two nonreactive conventional-type resins, a bisphenol-A-based phenoxy resin PAPHEN-301 and aromatic-based PETROLEUM RESIN, on the mechanical, thermal, and physical properties of methacrylated urethane resin-based UV-curable formulations were studied. A methacrylated urethane prepolymer was synthesized from isocyanatoethyl methacrylate (IEM) and polytetrahydrofurandiol (PTHF) via a one-step reaction. An increase in PAPHEN-301 content caused an increase both in tensile strength and elongation values of UV-cured polymeric films. On the other hand, an increase in PETROLEUM RESIN content caused a decrease both in tensile strength and elongation values of the polymeric films. However, thermooxidative properties were not affected by the introduction of either resin. It was also found that the water-absorption capacities of the UV-cured methacrylated urethane films depended on the type and amount of the nonreactive resins. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 1837–1845, 1998     

Synthesis of UV-curable acrylate polymer containing sulfonic groups for anti-fog coatings

A series of UV curable hydrophilic acrylate polymers containing sulfonic acid group was prepared via free radical copolymerization using 2-acrylamido-2-methyl propane sulfonic acid (AMPS) as hydrophilic monomer, which were used as prepolymers for anti-fog coatings. The expected structures were confirmed by FT-IR, ¹H NMR and gel permeation chromatography (GPC). These UV-curable acrylate polymers were then mixed with reactive diluents and photoinitiator to form coating formulas. Various substrates were coated with these formulas and cured under UV exposure to obtain transparent coatings with good adhesion and hardness. The anti-fog properties of UV-cured coating were measured by contact angle test and anti-fog test. The results showed that the AMPS content in prepolymer had a great influence on the anti-fog properties of UV-cured coating. The formula was optimized and the corresponding UV-curing anti-fog coating was manufactured. The test results indicated that the coatings showed good mechanical properties, great optical transparency and excellent anti-fog performance.     

Cationic photopolymerisation of divinylethers systems containing hydroxyvinylethers

Summary Diethyleneglycoldivinylether (DVE2) and triethyleneglycoldivinylether (DVE3) were photopolymerised together with monovinylethers and hydroxyalkylvinylethers, in order to study the curing reaction and to evaluate the properties of the films obtained. In the presence of the monovinylethers, the flexibility of the cured films increased and the Tg values decreased. In the presence of a hydroxyalkylvinyl ether, a stronger plasticisation effect was obtained and attributed to a chain transfer reaction involving -OH groups. Received: 24 November 1998/Revised version: 23 April 1999/Accepted: 12 May 1999     

Synthesis and properties of UV-curable hyperbranched polyurethane acrylate oligomers containing photoinitiator

The hyperbranched polyurethane acrylate oligomers containing photoinitiator were synthesized by modifying the second-generation hyperbranched poly(amine-ester) with isophorone diisocyanate-2-hydroxyethylacrylate and isophorone diisocyanate-2-hydroxy-2-methylpropiophenone at different feed ratio. The elemental analysis, FT-IR and NMR methods are used for structural characterization, molecular weights, and polydispersities, photosensitive groups and thermal properties of the oligomers were analyzed by gel permeation chromatography, UV–Vis spectra and thermogravimetric analysis, respectively. UV-curing properties were characterized by FT-IR at different curing time. In addition, the solubilities of the oligomers were also examined.     

Flame retardant aircraft epoxy resins containing phosphorus

As part of a program to develop fire resistant exterior composite structures for future subsonic commercial and general aviation aircraft, flame retardant epoxy resins are under investigation. Epoxies and their curing agents (aromatic diamines) containing phosphorus were synthesized and used to prepare epoxy formulations. Phosphorus was incorporated within the backbone of the epoxy resin and not used as an additive. The resulting cured neat epoxy formulations were characterized by thermogravimetric analysis, propane torch test, elemental analysis, microscale combustion calorimetry, and fire calorimetry. Several formulations showed excellent flame retardation with phosphorous contents as low as 1.5% by weight. The fracture toughness and compressive strength of several cured formulations showed no detrimental effect due to phosphorus content. The chemistry and properties of these new epoxy formulations are discussed.