UV固化涂料用长臂多官能度大分子光引发剂的合成及性能

利用乙氧基化季戊四醇/双季戊四醇与由聚乙二醇(PEG400)、异佛尔酮二异氰酸酯(IPDI)、2-羟基-2-甲基-1-[4-(2-羟基乙氧基)苯基]-1-丙酮(Irgacure 2959)反应形成的端异氰酸酯预聚体合成了2种可用于紫外光固化的长臂多官能度大分子光引发剂(MPIs)。利用红外光谱、核磁共振谱表征其结构。利用紫外-可见光谱研究了MPIs的光分解过程,用实时红外光谱研究了MPIs引发1,6-己二醇二丙烯酸酯(HDDA)的聚合动力学。结果表明:MPIs的引发效率稍高于Irgacure 2959;光引发速度随引发剂用量增加而提高;与Irgacure 2959相比,MPIs在光固化单体及树脂中的溶解性有所提高,光固化膜中残留光引发剂的迁移率降低。MPIs引发光固化聚合后的固化膜性能优异,表明MPIs是一类性能优异的大分子光引发剂。     

丙烯酸光固化阴极电泳涂料的制备

通过对合成的环氧丙烯酸树脂进行胺化开环,再在分子中接枝含双键单体半封闭异氰酸酯,得到阳离子化的树脂,在该树脂中引入合适的光引发剂和助剂,制得光固化阴极电泳涂料。采用FT-IR对产物结构进行表征;考察了树脂合成中单体用量、含双键单体半封闭物接枝比例、底料溶剂以及固化工艺中闪蒸温度、光引发剂、活性稀释剂等对涂膜性能的影响。结果表明:采用优化后的配方和工艺制备的光固化电泳工作液综合性能较好,呈乳白色蓝相,电泳得到的漆膜平整光滑、光泽高、硬度高、耐冲击性好、耐磨性优。     

紫外光固化改性水性聚氨酯树脂的合成与性能研究

以聚乙二醇、甲苯二异氰酸酯、二羟甲基丙酸、丙烯酸-2-羟基乙酯为原料合成了一组紫外光固化水性聚氨酯丙烯酸酯树脂(PUA),考察了不同条件对合成反应的影响,研究改性聚氨酯涂层的光固化性能。结果表明:合成的改性聚氨酯树脂可作为水性紫外光固化涂料,光引发剂用量为3%、活性稀释剂TMPTA30%时光固化效果好。     

UV固化丙烯酸粉末涂料的制备

以环氧型聚丙烯酸酯一甲基丙烯酸酯树脂为光固化树脂，Irgacure2959、Irgacure651、Irgacure184等为光引发剂制得了UV固化丙烯酸粉末清漆，研究了单组分和双组分光引发剂种类及用量对固化程度和漆膜性能的影响，探讨了固化工艺。结果表明，采用3％的Irgacure2959单组分光引发剂或1．5％Irgaeure2959和1．5％Irgacure651复合光引发剂体系，130℃下流平10min，固化30s，所得涂膜具有较佳的综合性能。     

UV光固化有机硅的制备及其光固化条件

以聚甲基三乙氧基硅烷(PTS)、γ-甲基丙烯酰氧基丙基三甲氧基硅烷(KH-570)、二甲基二乙氧基硅烷(DDS)为原料,以盐酸为催化剂通过溶胶凝胶法制备了可UV光固化的有机硅材料,利用FTIR和29SiNMR对材料进行了表征,研究了可UV光固化有机硅材料的缩聚程度和光引发剂种类对可UV光固化的有机硅材料固化速率的影响。结果表明,光引发剂中,Irgacure 369的固化速率最快,在相同的光照时间和引发剂质量分数下,使用Irgacure 369作为光引发剂的有机硅双键转化率达到了95.89%,同时通过改变光照时间和引发剂质量分数确定了最佳的光照时间和最佳引发剂质量分数分别为15 s和2%。     

印刷纸张用紫外光固化水性上光油的制备研究

研究了纸张用紫外光(UV)固化水性上光油低聚物共聚单体的配方、引发剂种类和用量及反应条件,合成了水性上光油低聚物,在此基础上与活性稀释剂、光引发剂等复合制备了纸张用紫外光固化水性上光油,研究了其组成和性能指标,优化出了光固化速率适宜、性能良好的水乳性紫外固化涂料。研究结果表明:当该复合涂料中光引发剂2959的用量为3%、活性稀释剂的质量为乳液质量的40%、附着力促进剂含量为0.6%时涂层光固化时间最短,涂膜综合性能最好。最终制得了光泽度佳、光滑、耐磨、紫外固化速率较快的水性上光油。     

新型光固化聚氨酯甲基丙烯酸酯的合成与表征

合成了适于粘接水晶饰品的新型聚氨酯甲基丙烯酸酯预聚体(PUMA),通过FT-IR和GPC对其结构进行了表征.探讨了光引发剂、活性单体等因素对其感光性能的影响.研究表明,含磷酰基的TPO光引发体系引发速率最快,感度值可达8.75 mJ/cm2,光引发剂用量在4%～6%比较适宜.单体的官能度和结构对体系的光固化速率有很大影响,多官能、分子链柔性好的单体有利于加快反应速率,TPGDA与PUMA组成的感光体系的固化速率较快,固化膜的柔韧性较好.     

邻羟基环己基丙烯酸酯光聚合动力学研究

采用实时红外光谱技术(RTIR)研究了邻羟基环己基丙烯酸酯(HCA)光聚合反应动力学,探讨了光照强度、光引发剂种类和浓度对其光聚合动力学的影响,并与脂肪族羟基丙烯酸酯单体丙烯酸羟乙酯(HEA)进行了对比。结果表明,最终双键转化率和相对反应速率随光强增大而增加;光引发剂浓度对最终双键转化率和反应速率的影响随引发剂不同呈现不同规律;与HEA相比,HCA具有更高的反应活性,但最终双键转化率较低。     

双固化聚硅氧烷丙烯酸酯的性能研究

添加活性稀释剂是调节光固化体系黏度、光固化反应速率、固化产物性能的有效手段。采用丙烯酸异辛酯(2-EHA)为活性稀释剂,利用实时红外(FT-IR)研究了活性稀释剂用量对双固化聚硅氧烷丙烯酸酯树脂(PSA)光聚合的影响。结果表明,稀释剂的加入不仅能改善体系的流变性能,同时稀释剂参与光聚合过程,提高体系的固化交联程度,改变交联网络,从而影响固化物的力学性能。通过红外跟踪研究了固化顺序(先光固化后湿气固化和先湿气固化后光固化)对体系中C=C双键和Si-OCH基团转化率的影响,结果表明,先光后湿的3固化顺序更有利于使体系达到高的转化率;DSC分析发现固化顺序对固化物玻璃化转变温度有一定影响。     

2-(4-甲氧基苯基)-4,6-双(三氯甲基)-S-三嗪光引发剂的合成及其光聚合动力学性能研究

以对甲氧基苯甲腈和三氯乙腈为原料合成了光引发剂2-(4-甲氧基苯基)-4,6-双(三氯甲基)-S-三嗪(MBTT),通过傅里叶红外光谱仪、核磁共振仪和紫外吸收光谱对所合成的产物结构进行了表征.并利用实时红外(RT-IR)对该引发剂进行了光聚合反应动力学研究,考察了单体、引发剂浓度和光强对引发速率及单体转化率的影响.结果表明,MBTT是一种高效的紫外光引发剂,在引发剂用量为0.1%时光聚合的单体转化率就能达到90%;随着光强的增大,单体的双键转化率和最大反应速率都增大,诱导期缩短;双丙烯酸酯类单体的双键转化率比三丙烯酸酯类单体的双键转化率要高.     

UV- and thermal-curing behaviors of dual-curable adhesives based on epoxy acrylate oligomers

Dual-curable adhesives were prepared using various epoxy acrylate oligomers, a reactive diluent, photoinitiators, a thermal-curing agent and a filler. The UV- and thermal-curing behaviors of the dual-curable adhesives were investigated using photo-differential scanning calorimetry (photo-DSC), Fourier transform infrared-attenuated total reflection (FTIR-ATR) spectroscopy, and the determination of the gel fraction, pendulum hardness and adhesion strength.The reaction rate and extent of UV curing were found to be strongly dependent on the concentration of CC bonds in the epoxy acrylate oligomers. The FTIR-ATR absorption peak areas representing the relative concentration of CC bonds in the epoxy acrylate oligomers and trifunctional monomer decreased with increase in UV dose because of photopolymerization. When the dual-curable adhesives were irradiated with UV light, the gel fraction increased with increase in CC bond contents in the epoxy acrylate oligomers. Also, after thermal curing, the gel fraction was highly enhanced due to the cross-linking reaction of the unreacted glycidyl groups in epoxy acrylate oligomers induced by the thermal-curing agent. This cross-linked structure of the dual-curable adhesives affects the pendulum hardness and adhesion strength.     

Development of rigid toughened photocurable epoxy foams

This study present a fast and efficient method for preparing photocurable rigid epoxy foams. A system based on the anionic photopolymerization of diglycidyl ether of bisphenol A (DGEBA) combined with a thiol-ene photopolymerization, was used. A tertiary diamine curing agent functionalized with four allyl groups was used in conjunction with a multifunctional thiol. The presence of several basic species, like tertiary amines, thiolates, polythioethers and alkoxide groups induced the anionic ring opening polymerization of the epoxy groups. At the same time the double bonds of the curing agent reacted with the multifunctional thiol generating polythioethers. The flexibility of the polythioethers modified the properties of the epoxy polymers, improving their toughness. Benzenesulfonyl hydrazide as foaming agent and zinc oxide as activator were added to DGEBA to produce the epoxy foams. The photopolymerization kinetics showed that conversion of the epoxide groups reached 80% in 600 s. Thermal curing studies performed by DSC showed that the main curing exotherm were determined at 84–89 °C, which match the temperature at which the photocuring was carried out in the UV light chamber (85 °C). It was found that the viscosity of the formulations plays a key role in the pore size of the foamed polymer, the higher the viscosity the larger the pore sizes. It was also determined that the impact resistance of the produced foams increased with increasing concentration of the thiol-ene system, as a consequence of a greater amount of polythioethers present in the co-network.     

Synthesis of superabsorbent resin by ultraviolet photopolymerization

Synthesis of superabsorbent resin (SAR) was achieved by a new method, that of direct UV photopolymerization, and in particular the synthesis of a SAR of acrylic acid–potassium acrylate copolymer by UV photopolymerization was investigated. Influences of ratio (mol) of acrylate monomer to acrylic acid monomer, photoinitiators, crosslinking agents, and exposure time of UV light on the water‐absorbent properties were investigated. The results showed that the water absorbency (Q) of SAR based on Irgacure 1700 or Irgacure 1800 was 545–530 mL/g, but under the same conditions Q was 450 mL/g for the SAR based on Irgacure 651. N,N′‐Methylene bisacrylamide, hydroethyl acrylate, and glycerol were used as crosslinking agents, of which N,N′‐methylene bisacrylamide was the most effective. It crosslinked the molecular chains through attending the copolymerization with acrylic acid (AA) and potassium acrylate. When the exposure time was 5 min, the value of Q was 1368 mL/g (the content of N,N′‐methylene bisacrylamide was 100 ppm). © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 1618–1624, 2004     

Synthesis and characterization of hyperbranched photosensitive polysiloxane urethane acrylate

A novel hyperbranched photosensitive polysiloxane urethane acrylate (HBPSUA) based on hyperbranched polyesters (HBP-OH) has been synthesized. HBP-OH was synthesized from N,N-diethylol-3-amine methylpropionate as AB₂ monomer and trimethylolpropane (TMP) as a core molecule. The structure of the oligomer was characterized by FTIR, GPC and ¹H NMR. The molecular weight of the oligomer is about 10,000 and the viscosity is 4446 cps at room temperature. The HBPSUA possesses good compatibility with most of acrylate monomers. The effect of photoinitiators, monomers and light intensity on the photopolymerization kinetics of the oligomer HBPSUA was investigated by real-time infrared spectroscopy (RT-IR). The results show that HBPSUA can well photopolymerize under UV-irradiation in the presence of photoinitiators. Irgacure 1700 showed the highest initiating efficiency among those tested photoinitiators. The optimal concentration of photoinitiator (Darocur 1173) is determined as 0.05 wt.%. The system of HBPSUA/TPGDA has the high conversion of double bond and polymerization rate, and they are 92.38% and 22.25 s⁻¹, respectively. Compared with linear systems (PSUA), HBPSUA has the higher photopolymerization rate and lower viscosity. The cured film of HBPSUA possesses good flexibility.     

Ultraviolet‐curing behavior and mechanical properties of a polyester acrylate resin

Ultraviolet (UV) curing technology has been widely used in many applications because it has several distinct advantages compared to solvent‐based processes or thermal‐curing technology. The effects of photoinitiator types and their contents as well as reactive diluent types and their contents on the UV‐curing behavior and mechanical properties of a UV‐curable polyester acrylate resin were investigated in this study. Three photoinitiators, Irgacure 184, Darocur 1173, and benzophenone, were used in this study. Hexanediol diacrylate, tripropylene glycol diacrylate, and trimethylol propane triacrylate were used as reactive diluents to modify the properties of the acrylate resin. The change of chemical structure during UV curing was monitored by FTIR. A universal testing machine was used to measure the tensile properties of various UV‐cured acrylate films of different compositions. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3921–3928, 2004     

pH‐response superabsorbant hydrogel synthesized by ultraviolet photopolymerization

A new synthesis method of pH‐response superabsorbent hydrogels (SHG) was achieved by direct ultraviolet (UV) photopolymerization, and in particular, the synthesis of SHGs of acrylic acid (AA), sodium acrylate (AANa), and methacrylcholine chloride (MACC) tricomponent copolymer by UV photopolymerization were investigated. The pH value responsive behavior of SHG with different monomer ratios of MACC and AA was researched, and SHG showed large swelling properties at pH value approximately 7. Influences of monomer ratio (mol) of AANa to AA, photoinitiators, crosslinking agents, and exposure time of UV light on the water absorbent properties were studied. The results showed that the water absorbent capacity of SHG based on photoinitiators: Esacure KTO46 or Irgacure 651 can reach comparatively high, N,N′‐Methylene bisacrylamide and diethylene glycol diacrylate (DEGDA) were high efficient crosslinking agents for its crosslinking the molecular chains through attending the copolymerization with monomers. When the exposure time was 10 min, the distilled water absorbency of SHG was 1503 mL/g under the condition: content of MACC, 14.3 wt %; monomer ratio (mol) of AANa to AA: 5.67; content of DEGDA and Irgacure 651, 0.0025 and 0.25 wt %. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1847–1852, 2007     

Morphologies and applied properties of free radical/cationic UV‐cured CPUA/TMPTMA/CER composite films

A UV‐cured composite film was prepared by free free‐radical photopolymerization from a blend containing oligomer cycloaliphatic polyurethane acrylate (CPUA) and reactive diluent trimethylolpropane trimethaacrylate (TMPTMA) with the same weight (coded as UT) in the presence of free free‐radical photoinitiator Irgacure 754. It was proved to be a homogeneous system featuring only one phase by means of scanning electron microscopy (SEM). Cycloaliphatic epoxy resin (CER) was introduced to enhance mechanical properties of the UV‐cured UT composite film in the presence of cationic photoinitiator Irgacure 250, and a series of UV‐cured CPUA/TMPTMA/CER composite films with different component ratios were prepared by free radical/cationic hybrid UV UV‐curing technique. Results of conversion curves, SEM, and Fourier‐ transform infrared spectroscopy illustrated that UT was cured faster than CER, leading to dynamically asymmetric photopolymerization‐induced phase ‐separation behaviors. The thermal and mechanical properties were evaluated via thermal degradation analysis, dynamic mechanical analysis, and stress–strain curves. Surface properties such as pencil hardness, pendulum hardness, shrinkage rate, contact angle, flexibility, and glossiness were also studied. All these measurements revealed that component ratios, intermolecular attractions, photopolymerization velocities, and viscosities had remarkably influenced on the morphologies and applied properties of UV‐cured composite films, and interpenetrating polymer network films had better comprehensive performances than other UV‐cured composite films with different microstructures. POLYM. COMPOS., 36:1177–1185, 2015. © 2014 Society of Plastics Engineers     

脱水蓖麻油酸环氧UV固化阴极电泳涂料的研制

脱水蓖麻油酸酯化改性环氧树脂,将其与二乙醇胺反应,而后产物在光引发剂和活性单体作用下制得UV固化阴极电泳涂料。研究了环氧树脂分子质量、催化剂种类及用量、反应温度对酯化反应的影响,探讨了酯化程度、胺开环率、活性单体的种类及用量对涂料稳定性及涂膜性能的影响。结果表明,选取环氧树脂E-44,酯化温度110℃,催化剂N,N-二甲基苄胺,添加质量分数0.8%～1%,酯化程度35%～40%,胺开环率≥60%,活性单体季戊四醇三丙烯酸酯质量分数15%～20%时,所制备的UV固化阴极电泳涂料涂膜固化快速完全,表面均匀丰满光亮,附着力好,耐溶剂性优。     

Superabsorbent resin of acrylic acid/ammonium acrylate copolymers synthesized by ultraviolet photopolymerization

A new method of synthesizing a superabsorbent resin (SAR) from an acrylic acid/ammonium acrylate copolymer by direct UV photopolymerization was studied. The effects of the degree of neutralization of acrylic acid, the photoinitiators, the crosslinking agents, and the UV‐light exposure time on the water absorbency (Q) were investigated. The results showed that Q of an SAR based on Irgacure 1700 or Irgacure 1800 and Irgacure 651 was high, reaching about 1200 mL/g, but under the same conditions, Q was low for an SAR based on other photoinitiators. The UV absorption spectrum proved that the photoinitiators matched the UV light source. Among the crosslinking agents, N,N′‐methylene bisacrylamide was more efficient than the others at a small concentration and a high value of Q. ¹³C‐NMR spectrometry was used to identify the mechanism of the crosslinking reaction through the esterification of hydroxyethyl acrylate (HEA) and 2‐hydroxypropyl acrylate with carboxylic acid group in acrylic acid/ammonium acrylate copolymerization, but the efficiency of the crosslinking reaction by esterification was lower than that of the copolymerization of vinyl groups in the crosslinking agent. Q of the acrylic acid/ammonium acrylate copolymer for the SAR reached 1255 mL/g under certain conditions (degree of neutralization of acrylic acid = 75%, Irgacure 651 concentration = 0.2 wt %, [HEA] = 0.2 wt %, exposure time = 10 min). © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 95: 546–555, 2005