Encapsulation of flexible organic light emitting diodes by UV-cure epoxy siloxane

In this research, a silicon additive was synthesized by reaction of the hydroxyl terminated poly-dimethyl siloxane (PDMS-OH) with 3-glycidoxy propyl tri-methoxy silane (TMS-epoxy). The synthesized silicon additive characterized and evaluated to use as a curing agent for preparing high-performance and impermeable epoxy resin for encapsulation of flexible optoelectronic devices such as thin film photovoltaics and polymer light-emitting diodes to protect them against water penetration and increase their lifespan. The synthesized additive was characterized by FTIR, NMR, and elemental analysis. Thermal properties of the UV curable resin were investigated by using DSC and DMTA. The prepared UV cure epoxy resin exhibited an appropriate melting temperature (56.19 °C). Contact angle test, SEM, and calcium test was used to investigate the properties of UV-cured coating resin. The water contact angle of the cured prepared resin film showed good hydrophobicity. The SEM results confirmed the uniformity of cured film and UV cure resin dispersion. Transparency and flexibility of the cured film to encapsulate the flexible light emitting diodes are acceptable. The permeability of cured film to water vapor was evaluated by calcium test, which shows the cured film suitability to encapsulate the FOLED. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48033.     

固化剂对环氧树脂耐水性能的影响研究

采用不同环氧树脂(EP)固化剂,并对固化物吸水率及吸水后的力学性能变化情况进行了研究。实验结果表明,新酸酐固化EP体系的平衡吸水率最小(0.95%),当达到吸水平衡时,弯曲强度和模量保持率分别为91%和96%左右,冲击强度略有下降,热变形温度下降10℃;新型酸酐固化EP体系是综合性能优良的耐水EP基体。     

Molecular design and properties of intrinsic flame-retardant P-N synergistic epoxy resin

In recent years, the poor weather resistance and aging resistance of additive flame retardants have caused researchers to pay attention to reactive flame retardants. A novel P-N coacting epoxy curing agent with intrinsic flame retardancy was designed and synthesized. The mechanical properties, crosslinking curing properties and flame-retardant properties of intrinsic flame-retardant epoxy resin were characterized. The results show that the cross-linking curing performance of hexa (3,5-diamino-1,2,4 triazolyl)-cyclotriphosphonitrile) (VCP) is lower than that of DDM. This is due to the decrease in cross-linking density caused by the VCP ring molecular structure. Therefore, the mechanical properties of the epoxy resin cured with VCP decreased, but the flame-retardant properties of the material significantly improved. The limiting oxygen index of the VCP/EP flame retardant epoxy thermosets was 27.3%, reaching the UL 94 V-1 level. The peak heat release rate and total heat release rate of the VCP/EP flame retardant epoxy thermosets were significantly reduced. The flame retardancy mechanism was studied by Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive spectroscopy, and x-ray photoelectron spectroscopy. The results show that the intrinsic flame-retardant P-N coacting epoxy resin has excellent curing and flame-retardant properties.     

Preparation and Application of a New Curing Agent for Epoxy Resin

A new curing agent based on palmitoleic acid methyl ester modified amine (PAMEA) for epoxy resin was synthesized and characterized. Diglycidyl ether of bisphenol A (DGEBA) epoxy resins cured with different content of PAMEA along with diethylenetriamine (DETA) were prepared. The mechanical properties, dynamic mechanical properties, thermal properties, and morphology were investigated. The results indicated that the PAMEA curing agent can improve the impact strength of the cured epoxy resins considerably in comparison with the DETA curing agent, while the modulus and strength of the cured resin can also be improved slightly. When the PAMEA/epoxy resin weight ratio is 30/100, the comprehensive mechanical properties of the cured epoxy resin are optimal; at the same time, the crosslinking density and glass transition temperature of the cured epoxy resin are maximal.     

Laboratory investigation of the properties of asphalt modified with epoxy resin

Epoxy asphalts were prepared by mixing styrene–butadiene–styrene (SBS) modified asphalt with epoxy resin. The curing process and morphology of epoxy asphalts were characterized by infrared spectroscopy and fluorescent microscope, respectively. The effects of epoxy resin contents, ratio of curing agent to epoxy resin and curing temperature on properties of epoxy asphalt were investigated. Results indicated that epoxy resin and epoxy asphalt showed similar curing efficiency. Epoxy asphalts can be cured at 120 or 60°C and its viscosity at 120°C can meet the demands of asphalt mixture mixing and paving. The chemical reaction of epoxy resin in epoxy asphalt is slow and reaction occurs not only with the curing agent but also carboxylic acid in epoxy asphalt. The microstructure of epoxy asphalt transforms from the dispersed structure to networks structure with epoxy resin content increasing and phase transition starts when 30 wt % epoxy resin present in asphalt. The softening point and tensile strength of epoxy asphalt increased with epoxy resin contents increasing. The softening point and tensile strength of epoxy asphalt were markedly improved when epoxy resin content was more than 30 wt %, which is attributed to formation of continuous structure of epoxy resin. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

含巯基聚硅氧烷改性环氧树脂的制备及性能

以双酚A环氧树脂（E51）为基料、聚醚胺（D?230）为固化剂、含巯基聚硅氧烷（PMMS）为改性剂,分别经过简单物理混合和化学改性的方法,制备了一系列聚硅氧烷改性环氧树脂（E51⁃D⁃PMMS）固化物。通过衰减全反射红外（ATR?FTIR）和X射线衍射仪（XRD）表征了固化物的结构特征;通过拉伸测试和冲击实验、扫描电子显微镜（SEM）、接触角测量（CA）、动态热力学分析（DMA）及中性盐雾实验探究了改性固化物的力学性能、热稳定性、防腐性能等。结果表明,化学改性的E51?D?PMMS固化物的综合物理化学性能优于简单物理改性的,当PMMS含量为1 %（质量分数,下同）时,改性固化物的拉伸强度为74.63 MPa,较改性前提高了13.5 %,断裂伸长率提高了40.2 %,冲击强度提高了43.7 %;水接触角从改性前的72.8 °增至100.3 °,表面能从39.4 J/m²降至17.4 J/m²,吸水率下降了44 %,耐水性能大大增强;其防腐性能和玻璃化转变温度（T_g）也有一定的提升。     

环氧树脂/空心玻璃微珠泡沫材料性能研究

以高强度环氧树脂为基体,表面改性处理的空心玻璃微珠(HGB)为填料,经高温固化制备了环氧树脂/HGB泡沫材料,并研究了HGB类型、HGB含量和固化剂用量对泡沫材料压缩性能的影响。研究发现,随着HGB填充量的增大,泡沫材料的密度和压缩强度均下降。当固化剂与环氧树脂物质的量比为0.85时,泡沫材料的抗压性能最好,压缩强度为40.19 MPa。偶联剂改性HGB可以有效改善HGB和基体树脂的粘合效果。当改性HGB质量分数为80%时,与未改性环氧树脂相比,环氧树脂/改性HGB泡沫材料压缩强度提高了5.0%,吸水率下降40.6%。     

胺类固化剂固化的双酚环氧树脂回收再利用的研究

双酚F型环氧树脂的耐酸性较低，在硝酸溶液中能够被安全分解。基于这一特性，本文探讨了一种环氧树脂化学回收再利用的方法。首先，用乙酸乙酯做溶液把该树脂的硝酸分解生成物从中性环境溶液中萃取出来，干燥后，替代部分环氧树脂，混入环氧树脂中，经固化剂固化后，制得再生树脂。并对原树脂和再生树脂的机械性能进行了比较。     

深海环境下环氧树脂吸水机理研究

利用环氧树脂TDE-85分别与固化剂651、T403固化制备了树脂基体样片,采用深海模拟设备进行高静水压吸水性能研究,并通过傅里叶红外(FT-IR)和扫描电镜(SEM)考察了环氧树脂高静水压处理前后结构变化。研究结果表明,高静水压环境下,环氧树脂的吸水过程分为3个阶段,即快速吸水阶段、缓慢吸水阶段和吸水平衡阶段;环氧树脂自由体积和极性基团浓度决定着高静水压力对水分子的进入起促进还是抑制作用;水分子的大量进入会导致树脂基体发生水解等不可逆破坏。     

环氧树脂柔性固化剂研究综述

环氧树脂柔性固化剂种类众多,主要介绍改性脂肪族胺、脂环族胺、柔韧性酸酐、聚合物类环氧树脂柔性固化剂研究进展。认为对固化剂分子进行没计,开发合成柔性固化剂来增韧环氧树脂,可提高环氧固化物性能。     

固化剂对有机改性凹凸棒石/聚苯胺环氧树脂复合涂层性能的影响

固化剂对涂层的防腐、力学性能起着至关重要的作用.以环氧树脂为成膜物质,采用原位复合法在环氧树脂体系中合成有机改性凹凸棒石/聚苯胺(OAT/PAn)复合涂层,分别使用改性脂肪胺固化剂593、酚醛胺固化剂T-31以及聚酰胺固化剂650对上述涂层进行固化,讨论了不同种类固化剂对涂层的化学结构、防腐和力学性能以及耐水性能的影响.利用FTIR 对比了各涂层的固化结构,证明了三种固化剂均可使复合涂层固化;SEM结果表明,593固化剂固化涂层的致密性最好;电化学实验结果表明,593固化剂的固化涂层防腐性能最佳,腐蚀电位达到了Ecorr=-318 mV,腐蚀电流密度Icorr=1.193×10-6 A·cm-2;通过划格法评价了各涂层的附着力,发现593固化剂固化效果最好,附着力可达5B;对比浸泡168 h后涂层的耐水性发现,593固化剂耐水性最好.     

Graphitic carbon nanofiber (GCNF)/polymer materials. II. GCNF/epoxy monoliths using reactive oxydianiline linker molecules and the effect of nanofiber reinforcement on curing conditions

Reactive (r‐) graphitic carbon nanofibers (GCNFs) with 3,4'‐oxydianiline (ODA), r‐GCNF‐ODA, capable of covalent binding to an epoxy resin during thermal curing, are prepared by reaction of GCNFs surface‐derivatized with ODA linker molecules (GCNF‐ODA) with butyl glycidyl ether. The thermal curing characteristics of r‐GCNF‐ODA/epoxy resin mixtures having nanofiber loadings of 0.3 wt% and 1.3 wt% are analyzed by differential scanning calorimetry (DSC). The quality of the cured GCNF/epoxy nanocomposites is assessed through bending tests and scanning electron microscopy (SEM). These results indicate that the presence of r‐GCNF‐ODA nanofibers affects the thermal curing process, and that additional heating is required to achieve cured nanocomposites at higher nanofiber loadings. Reaction of GCNF‐ODA nanofibers with butyl glycidyl ether prior to mixing with an epoxy resin gives more well‐dispersed r‐GCNF‐ODA/epoxy resin mixtures and r‐GCNF‐ODA/epoxy nanocomposites having better flexural strength than the corresponding GCNF‐ODA/epoxy materials. POLYM. COMPOS., 26:128–135, 2005. © 2005 Society of Plastics Engineers     

Synthesis and characterization of emulsion‐type curing agent of water‐borne epoxy resin

Self‐emulsified water‐borne epoxy curing agent of nonionic type was prepared using triethylene tetramine (TETA) and derivative of epoxy resin as a capping agent, which was synthesized by liquid epoxy resin (E51) and polyethylene glycol (PEG), and the curing agent possessed emulsification and curing properties at the same time. The curing agent with good property of emulsifying liquid epoxy resin could be obtained under the condition of the molar ratio of PEG : E51 : TETA as 0.8 : 1 : 3.5 at 80°C for 5 h. The mean particle size of the emulsion liquid was about 220 nm with the prepared curing agent and epoxy resin at the mass ratio of 1 : 3. The structure of the emulsion‐type curing agent was confirmed by FTIR and ¹H NMR spectra, and the mechanism of cured film formation was also analyzed by SEM photographs. The cured film prepared by the emulsion‐type curing agent and epoxy resin under ambient cure conditions showed good properties even at high staving temperature. This study provides useful suggestions for the application of the water‐borne epoxy resins in coating industry. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2652–2659, 2013     

Epoxy resin cured by bisphenol A based benzoxazine

Bisphenol A based benzoxazine was prepared from bisphenol A, formaline, and aniline. This benzoxazine was used as a hardener of the epoxy resin. Curing behavior of the epoxy resin and the properties of the cured resin were investigated. Consequently, curing reaction proceeded without a curing accelerator. The molding compound showed good thermal stability under 150°C, which corresponded to the temperature in the cylinder of injection molding. Above 150°C, the curing reaction proceeded rapidly. The cured epoxy resin showed good heat resistance, water resistance, electrical insulation, and mechanical properties compared with the epoxy resin cured by the bisphenol A type novolac. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68: 1903–1910, 1998     

环氧树脂/胺化酰亚胺潜伏性固化体系的制备

为了深入了解新型环氧树脂/胺化酰亚胺潜伏性固化体系的使用条件,采用差示扫描量热（DSC）技术考察了E–51型环氧树脂/脂肪族胺化酰亚胺体系的非等温固化反应过程,研究了体系的固化条件及固化物性能。结果表明：E–51与固化剂的物质的量比为1∶0.1;体系的固化条件为固化150℃/2 h,后固化180℃/1 h。树脂试样制备工艺简单,无挥发性有机溶剂,树脂混合物贮存稳定性好。体系固化反应平稳且放热量较少,完全固化后的树脂试样具有良好的耐水性、耐热性和物理机械性能。     

胺化酰亚胺固化的环氧树脂体系的特性及其固化机理

能热分解成异氰酸酯和叔胺的胺化酰亚胺是很好的潜伏性环氧树脂固化剂和环氧-酸酐体系的固化促进剂,它固化的环氧树脂有许多优异的性能,特别是高的韧性和粘接强度。由胺化酰亚胺热分解速度控制的、高温下相对慢的、独待的固化机理是韧性的起因。     

New thermosetting resin from poly(p‐vinylphenol) based benzoxazine and epoxy resin

Poly(p‐vinylphenol) (VP) based benzoxazine was prepared from VP, formaline, and aniline. The curing behavior of the benzoxazine with the epoxy resin and the properties of the cured resin were investigated. Consequently, the curing reaction did not proceed at low temperatures, but it proceeded rapidly at higher temperatures without a curing accelerator. The reaction induction time or cure time of the molten mixture from VP based benzoxazine and epoxy resin was found to decrease, compared with those from conventional bisphenol A based benzoxazine and epoxy resin. The curing reaction rate of VP based benzoxazine and epoxy resin increased more than that of conventional bisphenol A based benzoxazine and epoxy resin. The properties of the cured resin from neat resins and from reinforced resins with fused silica were evaluated. The cured resins from VP based benzoxazine and epoxy resin showed good heat resistance, mechanical properties, electrical insulation, and water resistance compared to the cured resin from VP and epoxy resin using imidazole as the catalyst. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 555–565, 2001     

无溶剂环氧防腐涂料的制备和性能研究

开发了一种以腰果酚改性胺为固化剂的无溶剂环氧防腐涂料,介绍了环氧树脂、固化剂、稀释剂以及填料等原料的选择,探讨了环氧树脂与腰果酚改性胺的固化机理,并考察了硅烷偶联剂对涂层防腐性能的影响。检测结果表明,环氧树脂与腰果酚改性胺的固化主要以环氧基与胺基之间的反应为主;硅烷偶联剂可以提高涂层的附着力,有效地增强涂膜的耐水性。     

CA型环氧树脂固化剂性能研究

用ＩＲ光谱表征了自制ＣＡ型环氧树脂固化剂的结构特点,测定了ＣＡ型固化剂的固化特性,固化树脂的性能和增塑效果。实验结果表明,ＣＡ型固化剂能使环氧树脂涂料在潮湿表面和带油表面上固化成膜,其固化的树脂具有良好的耐蚀性,冲击强度较二乙撑三胺固化的树脂有较大提高,同时也是一种较好的环氧树脂用增塑剂。     

Thermo-mechanical properties of rosin-modified o-cresol novolac epoxy thermosets comprising rosin-based imidoamine curing agents

Rosin-modified o-cresol novolac epoxy resin (AEOCN) was synthesized by condensation of rosin acid with o-cresol formaldehyde novolac resin (AOCN). The AEOCN resin was further epoxidized using epichlorohydrin and sodium hydroxide. Rosin-based imidoamine curing agents (IAMDK, IASDK, and IAEDK) were also prepared by reacting dimaleopimaryl ketone (DMPK), a dimerized rosin product with aromatic diamines. The chemical structures of all synthesized products were confirmed by FTIR, ¹H-NMR, ¹³C-NMR, and DEPT-135° spectroscopic techniques. The curing process of rosin-modified epoxy cured with imidoamine crosslinkers was studied using differential scanning calorimetry (DSC) and the results were compared to o-cresol novolac epoxy resin (EOCN) and some previously reported commercial-based systems. The thermal and mechanical properties of the cured epoxy thermosets were determined using a thermogravimetric analyzer (TGA) and a universal testing machine (UTM), respectively. The chemical resistance analysis was carried out by immersing cured epoxy coated panels in 1M NaOH, 1MHCl, and 1M NaCl solutions. The results were evaluated in terms of % weight loss method and the morphological changes that appeared due to chemical exposure were also investigated via scanning electron microscopy (SEM). This study presents the economical synthetic approach towards high-performance bio-based epoxy coating materials impending to replace some of the petrochemical compounds in coating industries.