Preparation and evaluation of epoxy methacrylate UV‐curable coatings containing phthalazinone

Epoxy methacrylate resin (EMA) UV‐curable coatings exhibit high reactivity, low viscosity and excellent chemical resistance in environmentally friendly coatings. A novel EMA containing phthalazinone moieties for high temperature resistant UV‐curable coatings was synthesized. The formulations were cured with hexanediol diacrylate (HDDA) and trimethylol propane triacrylate (TMPTA) as reactive diluents promoted by a photoinitiator, and then interpenetrating polymer networks were generated. The mechanical, chemical and thermal properties of the clear coatings were characterized using Chinese National Standard methods (GB). EMA was used with UV radiation curing in combination with 6.7 wt% of HDDA and 13.4 wt% of TMPTA, and the properties of the cured films were as follows: pencil hardness of 5 H, 30% NaOH resistance for 30 days, 15% HCl resistance for 10 days, 3% NaCl resistance for 30 days and 5% weight loss temperature of 300.5 °C. EMA UV‐curable coatings containing phthalazinone exhibit excellent chemical and thermal stability, and could be potential candidates for UV‐curable zero volatile organic compound coatings applied in the fields of salt spray corrosion, strong radiation and high‐temperature resistance. Copyright © 2009 Society of Chemical Industry     

Mechanical properties study of photocured paperboard surface treated with aliphatic epoxy diacrylate

In order to improve the quality of paperboard (a well‐known packing material) surface by photocuring method, different formulations were developed with aliphatic epoxy diacrylate (EA‐1020) oligomer along with reactive monomers of various functionalities. The reactive monomers are tripropylene glycol diacrylate (TPGDA), a difunctional monomer, and trimethylol propane triacrylate (TMPTA), a trifunctional monomer. 2‐Benzyl‐2‐dimethylamino‐1(4morpholinophenyl) butanone‐1 (Irgacure 369), a photoinitiator (2%), was incorporated into the formulations to initiate photocuring reaction. The formulated solutions were coated on clean glass plate and irradiated under UV radiation of different intensities. Different physical properties like pendulum hardness and gel content of the cured films were studied. The formulation containing TMPTA showed better properties. After characterization of the films, these formulations were applied on paperboard surfaces and cured under the same UV radiation. Various physicomechanical properties such as pendulum hardness, tensile properties, surface gloss, adhesion, abrasion, and water uptake were studied. The best performance was obtained at 12 passes of radiation with 18% TMPTA‐containing formulation. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1774–1780, 2003     

超支化聚氨酯丙烯酸酯的性能与UV固化动力学研究

采用2-羟基-2-甲基-1-苯基-1-丙酮（Darocur 1173）作为超支化聚氨酯丙烯酸酯（HBUA）的紫外光（UV）固化引发剂,研究了Darocur 1173用量、活性单体种类及用量对HBUA固化膜机械性能的影响,并用光差扫描量热法（Photo—DSC）对HBUA的光固化动力学进行了表征。结果表明,随着Darocur 1173用量的增加,光固化膜的摆杆硬度及冲击强度增大,最大光固化反应速率Rp^max提高,到达Rp^max的时间缩短。己二醇二丙烯酸酯（HDDA）作活性单体更有利于提高光固化膜的机械性能,并有利于促进光固化反应的进行。Darocur 1173和HDDA的适宜用量分别为4％（wt）和20％（wt）。     

Synthesis of Transesterified Palm Olein‐Based Polyol and Rigid Polyurethanes from this Polyol

Transesterification of palm olein with glycerol can increase the functionality by introducing additional hydroxyl groups to the triglyceride structure, an advantage compared to using palm olein directly as feedstock for producing palm‐based polyol. The objective of this study was to synthesize transesterified palm olein‐based polyol via a three‐step reaction: (1) transesterification of palm olein, (2) epoxidation and (3) epoxide ring opening. Transesterification of palm olein yielded approximately 78 % monoglyceride and has an hydroxyl value of approximately 164 mg KOH g^?1. The effect of formic acid and hydrogen peroxide concentrations on the epoxidation reaction was studied. The relationships between epoxide ring‐opening reaction time and residual oxirane oxygen content and hydroxyl value were monitored. The synthesized transesterified palm olein‐based polyol has hydroxyl value between 300 and 330 mg KOH g^?1 and average molecular weight between 1,000 and 1,100 Da. On the basis of the hydroxyl value and average molecular weight of the polyol, the transesterified palm olein‐based polyol is suitable for producing rigid polyurethane foam, which can be designed to exhibit desirable properties. Rigid polyurethane foams were synthesized by substituting a portion of petroleum‐based polyol with the transesterified palm olein‐based polyol. It was observed that by increasing the amount of transesterified palm olein‐based polyol, the core density and compressive strength were reduced but at the same time the insulation properties of the rigid polyurethane foam were improved.     

活性单体对超支化聚氨酯丙烯酸酯的影响

研究了活性单体种类及用量对超支化聚氨酯丙烯酸酯(HBUA)光固化膜机械性能的影响,并用光差扫描量热法(Photo-DSC)对超支化聚氨酯丙烯酸酯的光聚合反应速率进行了研究.结果表明,己二醇二丙烯酸酯(HDDA)比三羟甲基丙烷三丙烯酸酯(TMPTA)能更好地调节HBUA固化膜的综合性能,并促进UV固化反应的进行.HDDA的适宜质量分数为20%.     

Polymeric Michler's ketone photoinitiator containing coinitiator amine

Novel polymeric photoinitiator based on Michler's ketone (MK) (PMKPR) was synthesized by introducing coinitiator amine and MK into the same polymeric chain as well as the low‐molecular weight model compounds. UV–vis spectra show that PMKPR has the characteristic UV–vis absorption of MK. The photobleaching behavior of PMKPR and the model compounds were studied, indicating that the photobleaching rate of PMKPR is much faster than that of model compounds. Two types of monomer with different functionality, 2,2‐bis[4‐(acryloxypolyethoxy)phenyl] propane (A‐BPE‐10) and trimethylopropane triacrylate (TMPTA), were chosen to be initiated by these photoinitiators. The result indicates that PMKPR is an efficient photoinitiator for polymerization of A‐BPE‐10 and TMPTA. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers     

Mechanical properties development of sodium alginate films with additives by UV‐radiation processing

To improve mechanical properties of polymer films; sodium alginate (SA) films was prepared with ethylene glycol (EG) and photocured. The formulation was prepared at various concentration with EG and photoinitiator (2%) in methanol. The mechanical properties were optimized in case of monomer (EG) concentration, soaking time, and radiation dose of intensities. The highest polymer loading (PL) was 7.1% and tensile strength (TS) of the film was 37.9 MPa were found for 3 min soaking in 5% EG containing formulation at 20th pass of UV radiation; the highest value (22%) of elongation at break (Eb) was obtained at 1 min soaking time at 15th passes of UV doses. The mechanical properties improvement of the films varied acrylic monomers; such as 2‐ethylhexylacrylate (EHA), 1,4‐butanediol diacrylate (BDDA), and trimethylpropane triacrylate (TMPTA) were used as additives (2%) in the optimized formulation. The highest PL (12.7%) and TS (42.2 MPa) of the films are at 5% EG, 2% TMPTA, and 2% photoinitiator in methanol at 3 min soaking time at 20th pass of UV radiation. The highest Eb (25%) was obtained using additives 2% EHA additives in 5% EG and 2% photoinitiator in methanol at 3 min soaking time. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

LCD用UV固化胶黏剂的研制

以聚酯多元醇、二异氰酸酯和丙烯酸羟乙酯为原料,合成聚氨酯丙烯酸预聚体,并在此基础上通过添加活性稀释单体、光引发剂等配制成UV固化胶黏剂。通过分析不同组分在LCD液晶灌注口密封及金属管脚固定的粘接性能影响,确定合成预聚体所需的聚酯多元醇种类及丙烯酸羟乙酯的合适用量,同时确定配胶所需活性稀释单体与光引发剂的合适用量。最后制得粘接性能好、耐候性能佳,可满足LCD产品生产工艺的性能要求的UV固化胶黏剂。     

Effect of CaCO3 on the performance of Partex surface modification by ultraviolet radiation curing method

Several UV‐curable formulations containing epoxydiacrylate (EB‐600) oligomer with a tri‐functional monomer, trimethylol propane triacrylate (TMPTA), and photoinitiator Irgcure‐369 were developed to improve the surface of Partex. Filler or extender CaCO₃ was incorporated into the solution. Thin polymer films were prepared on glass plate with these formulated solutions and finally applied on polished Partex surface, and both were cured under UV‐radiation. The properties of UV‐cured thin films were studied as a function of CaCO₃ concentration. Pendulum hardness and gel content were found to decrease on glass plate with the increase of CaCO₃ concentration. Pendulum hardness, scratch hardness, and abrasion resistance of the cured Partex were found to be higher with the increase of CaCO₃ content up to 4%. Thus, the formulation containing 4% CaCO₃ showed the best performance over all formulations containing CaCO₃. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1858–1867, 2001     

Influence of pigment properties on UV‐curing efficiency

The curable formulations containing monomer‐diacrylate, photoinitiator‐p‐methoxybenzoyldiphenylphosphine oxide/benzyldimethylketal, additive reactive‐triethylamine, and inorganic thermoresistant pigments‐white, red, green, and blue were cured by UV exposure films. A series of experiments was carried out to investigate the relationship between the particle size distribution of the inorganic pigment and the colorimetric and mechanical properties of the UV acrylic curable coatings. Pendulum hardness and appearance of the films depend on the content and particle size distribution of the pigment. Optimal particle size distribution and pigment content were established to obtain the best films concerning their pendulum hardness and chromatic parameters. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 247–252, 2007     

Effect of alkali and ultraviolet (UV) radiation pretreatment on physical and mechanical properties of 1,6‐hexanediol diacrylate–grafted jute yarn by UV radiation

To improve the physicomechanical properties of jute yarn, grafting with 1,6‐hexanediol diacrylate (HDDA) monomer was performed by a UV radiation technique. A series of HDDA solutions of various concentrations in methanol were prepared. A small quantity of photoinitiator (Darocur‐1664) was also added to HDDA solutions. To optimize the conditions for grafting, the effects of monomer concentration, soaking time, and radiation doses were studied by varying the number of soaking times along with variation of monomer concentrations and UV radiation intensities. The extent of polymer loading and the mechanical properties like tensile strength (TS), elongation at break (Eb), and tensile modulus of both treated and untreated jute were investigated. The highest tensile strength, polymer loading, and modulus were achieved with 5% HDDA concentration, 5 min soaking time, and the 4th pass of UV radiation. This set of conditions was selected as optimum and produced enhanced tensile strength (67%), modulus (108%), and polymer loading (11%) over those of virgin fiber. To further improve the mechanical properties the jute yarns were pretreated with alkali (5% NaOH) solution and after that the alkali‐treated yarn were treated under UV radiation of various intensities. The pretreated samples were grafted with optimized monomer concentration (5% HDDA). Increased properties of alkali + UV‐pretreated and grafted samples such as polymer loading (12%), tensile strength (103%), elongation at break (46%), and modulus (114%) were achieved over those of virgin jute yarn. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 18–24, 2004     

Effect of fillers on curing of wood surfaces with polyester oligomers by ultraviolet radiation

A set of formulations was prepared with polyester acrylate (oligoester M‐9050) oligomers in combination with reactive diluents of different functionalities such as ethylhexyl acrylate, tripropylene glycol diacrylate , and trimethylol propane triacrylate (TMPTA). The thin films were prepared with these formulated solutions under UV radiation on a glass plate, and their physical properties such as pendulum hardness and gel content were studied. The formulation containing TMPTA showed the greatest pendulum hardness and gel content. The polished wood surfaces were cured with these formulated solutions. Physical properties such as pendulum hardness gloss at 20° and 60° angles, adhesion, abrasion resistance, and scratch hardness of UV‐cured surfaces of the wood were characterized. The formulation containing TMPTA had the best physical properties. Two types of filler, sand and talc, were used in the base coat to obtain these better properties. Both fillers improved the properties; however, the 1% sand– and 4% talc–containing formulations performed better. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3826–3834, 2003     

Surface modification of polypropylene sheets by UV‐radiation grafting polymerization

1,6‐Hexanediol diacrylate (HDDA) was grafted onto polypropylene (PP) substrates in the presence of benzophenone (BP) and isopropylthioxanthone (ITX) photoinitiators, and then polyurethane acrylate formulations were coated onto the HDDA‐g‐PP substrates, using UV radiation. The amount grafted and the grafting efficiency of the polymerizations were determined gravimetrically. The effects of the photoinitiator concentration and the UV radiation intensity on the physicochemical surface properties and the grafting efficiency of the UV‐radiation grafting polymerizations were characterized in detail using contact‐angle measurements, Fourier transform infrared spectroscopy with attenuated total internal reflection, and scanning electron microscopy. The results showed that the amount grafted and the surface polarity of the HDDA‐g‐PP substrates both increased linearly with increasing BP photoinitiator concentration and UV radiation intensity, and that the addition of a small amount of ITX markedly enhanced both parameters, probably due to photosensitization. The adhesion of the UV‐cured coating onto the HDDA‐g‐PP substrates was evaluated using the crosshatch adhesion test. The results indicated that the amount of HDDA grafted onto the PP substrates should exceed about 1 mmol/cm² for satisfactory adhesion with the UV‐cured coating. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1446–1461, 2006     

Effect of photosensitive groups on the photoefficiency of polymeric photoinitiators

The purpose of this paper is to determine the effect of photosensitive groups contained in the main chain of polymeric photoinitiator on photopolymerization. Through polycondensation of toluene-2,4-diisocyanate (TDI), different diamines and N-phenyldiethanolamine (PDEA), three novel polymeric photoinitiators containing in-chain benzophenone (BP) and coinitiator amine were synthesized in comparison with the corresponding side-chain ones. FT-IR, ¹H NMR and GPC analyses confirm the structures of all polymers. UV-Vis spectra showed that the maximal absorption and the molar extinction coefficient of polymeric photoinitiator can be greatly improved by the electron donating groups and the imino nitrogen that directly link to BP structure. The photopolymerization of trimethylolpropane triacrylate (TMPTA) and PU prepolymer, initiated by these polymeric photoinitiators, was studied by photo-DSC. The results indicate that the location of photosensitive group has an important effect on the photoefficiency of polymeric photoinitiators. The efficiency order of polymeric photoinitiators comprising in-chain BP is different from that of the side-chain ones: PUIBA-s and PUIBA-n are the most efficient for TMPTA and PU prepolymer, respectively.     

High performance UV curable polyurethane dispersions by incorporating multifunctional extender

UV curable polyurethane dispersions (UV-PUDs) were synthesized and characterized in terms of prepolymer chain length, content of crosslinking agent (1,3-dihydroxy-2-propanone) and type of polyol. With decreasing prepolymer chain length and increasing crosslinking agent content, high hardness, modulus and low elongation at break were obtained. Among three types of polyol (PPG, PTMG, and PTAd) PTAd-based UV-PUD showed the highest tensile strength. All the UV-PUDs were tack free before UV-curing and showed improved solvent and hydrolysis resistant.     

光敏有机硅聚氨酯丙烯酸酯预聚体性能的研究

考查了光引发剂、活性单体对光敏有机硅聚氨酯丙烯酸酯预聚体（PSUA）胶膜的耐水性、拉伸强度、伸长率、硬度、柔韧性和热稳定性的影响。结果表明，胶膜具有优良的耐水性，吸水性低于4％。含单官能度单体的PSUA胶膜的接触角大于含多官能度单体的，含有IBOA的体系接触角达103．6°；当选择引发效率高的裂解型光引发剂，用量为0.5％～1％时，胶膜具有较高的接触角。含多官能度单体胶膜的拉伸强度高于含单官能度单体的体系，但伸长率较小。含TMPTA体系的胶膜的硬度最大，为0．575。胶膜具有较好的柔韧性和热稳定性，其柔韧性达到1mm级，在300℃时失重为4.61％。     

UV固化不饱和聚酯树脂在涂料中的应用研究

以不饱和聚酯为光敏预聚物,加入光引发剂制得天然大理石表面紫外光固涂层(流水线作业)。研究了光引发剂用量对涂层性能的影响,并将UV固化与化学固化浇注体的力学性能和耐热性进行了对比。结果表明,紫外光固化不饱和聚酯树脂涂层的固化效果,硬度和亮度都达到化学固化的效果,且生产效率大大提高。     

Curing of crust leather by ultraviolet radiation with urethane acrylate: Role of pigment

Eight different formulations were developed with four diacrylate reactive monomers such as tripropylene glycol diacrylate (TPGDA), 1,4‐butanediol diacrylate (BDDA), 1,6‐hexanediol diacrylate (HDDA), and 2‐ethylene glycol dimethacrylate (EGDMA) and aromatic urethane diacrylate (M1100) in order to modify the crust leather surface. To study the effect of pigment on the performance of ultraviolet (UV)‐cured leather surface, 1% pigment (congored) was incorporated in the formulations. Irgacure 369 (2%) was also used in the formulation as photoinitiator. The gel content, tensile strength, elongation at break, and pendulum hardness of UV‐cured thin films with and without pigment was studied. The films without pigment produced better properties. Among all the diluents, BDDA‐containing films showed the best performance. Different properties of UV‐coated leather surface such as pendulum hardness, tensile strength, elongation, gloss (at 20° and 60°), adhesion, and abrasion were studied. Effect of gloss on simulating weathering was also performed. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 692–697, 2002     

Synthesis and properties of ultraviolet‐curable resins via a thio–ene (thiol and allyl) addition reaction

Benzophenone diallyl ester (I) and benzophenone tetraallyl ester (II) based on 3,3′,4,4′‐benzophenone tetracarboxylic dianhydride (BTDA) with allyl alcohol (AAL) were synthesized. Glycidyl methacrylate (GMA) was added to I and formed diallyl diglycidyl methacrylate (III). These BTDA‐based allyl‐containing compounds (II and III) reacted with 1,4‐butanedithiol and 4,4′‐thiol‐bisbenzene‐thiol to produce ultraviolet (UV)‐curable resins via a thio–ene addition reaction. The ester (III) was cured easily when exposed to UV or sunlight radiation without any photoinitiator and only required a lower thermal curing temperature. The diallyl ester (I) and tetraallyl ester (II) required the addition of benzophenone to increase the photosensitivity, which reduced the exposition time. These resins used AAL as a monomer to successfully reduce the oxygen effect of the photocuring. The resin BTDA–2Allyl–2GMA had a glass‐transition temperature of 166°C and a hardness of 6H. The resultant UV‐curable coatings had excellent hardness, chemical resistance, adhesion, and tensile properties. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1878–1885, 2002     

Synthesis of UV‐curable difunctional silane monomer based on 3‐methacryloxy propyl trimethoxysilane (3‐MPTS) and its UV‐curing characteristics and thermal stability

In the present investigation, silicon containing UV‐curable difunctional monomer was synthesized by reacting 3‐methacryloxy propyl trimethoxysilane (3‐MPTS) with acrylic acid using anhydrous ether as a solvent under inert atmosphere. The synthesized acryloxymethacryloxy silane monomer was characterized by FTIR, ¹H‐NMR, and ¹³C‐NMR spectroscopy. The silane monomer along with 4 wt % photoinitiator (Darocure 1173) was cured under UV‐light for different exposure time. The curing characteristic of the monomer was investigated using FTIR spectroscopy. The conversion of the double bond due to curing has been evaluated from the peak intensity of the C?C double bond (at 1636 cm^?1) in the FTIR spectrum considering the peak intensity at 1720 cm^?1 due to C?O as internal standard. The maximum double bond conversion is observed to be 72%. The optimum cure time for the silane monomer has been estimated to be 7.8 sec. The UV‐cured sample decomposes at 440°C. The char residue is 35% at 700°C. The synthesized UV‐curable silane monomer may be useful for UV‐coating formulations, for fabrication of 3D‐objects by lithographic technique and as a precursor for organic–inorganic hybrid materials. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010