Epoxy Conversion Research Articles

Rational design of a room‐temperature curing method, based on the epoxy–thiol click reaction, for UV‐curable hard coatings with ultrahigh strength and adhesion

AbstractIn recent years, there has been a growing demand for UV‐curable hard coatings because they offer several advantages, for example, lower energy consumption and the absence of volatile organic compound emissions. Anionic UV curing with photobase generators (PBGs), such as epoxy–thiol cross‐linking, enables curing under ambient conditions. However, designing a room‐temperature photoanionic curing system for epoxy–thiols remains challenging due to the complex effects of resin combinations on the cured products, thus making it difficult to prepare films with high hardness. Herein, we present a controlled reaction design for an anionic UV‐curing system by combining the chemical structures of epoxy resins and multifunctional thiols. The anionic UV‐curing system using PBGs that generate organic superbases demonstrated UV‐delayed curability, as evidenced by FT‐IR and photorheological analyses. To achieve high hardness, it was necessary to create the thiols with ultrarigid structures; epoxy resins with a bisphenol F structure were optimal for reacting with thiols for ultrarigid structures. This combination afforded an indentation hardness of 262 MPa with an epoxy conversion rate of 77% even at room temperature.

Evaluating models that predict epoxy conversion using rheological properties.

Simultaneous rheology and conversion measurements of neat and composite epoxy resins reveal that conventional models neither accurately nor fully describe the relationship between rheology and conversion. We find that models predicting thermoset conversion based on mixing rules of rheological properties are quantitatively inaccurate and do not account for chemical gelation. Models based on percolation theory and the divergence of the viscosity at the gel point are more accurate but only valid before the gel point. Here, we propose the use of the generalized effective medium (GEM) model, which incorporates the divergence of rheological properties on both sides of the critical gel point. We show that the GEM model works well for both neat resins and filled systems, and the resulting parameters estimate the gel point and scaling behavior on either side of the sol-gel transition.

Thioxanthone-Based Siloxane Photosensitizer for Cationic/Radical Photopolymerization and Photoinduced Sol-Gel Reactions.

In this investigation, a multifunctional visible-light TX-based photosensitizer containing a siloxane moiety (TXS) was designed with a good overall yield of 54%. The addition of a siloxane moiety enabled the incorporation of a TX photosensitizer into a siloxane network by photoinduced sol-gel chemistry, thus avoiding its release. Both liquid 1H and solid-state 29Si NMR measurements undeniably confirmed the formation of photoacids resulting from the photolysis of the TXS/electron acceptor molecule (Iodonium salt), which promoted the photoinduced hydrolysis/condensation of the trimethoxysilane groups of TXS, with a high degree of condensation of its inorganic network. Notably, the laser flash photolysis, fluorescence, and electron paramagnetic resonance spin-trapping (EPR ST) experiments demonstrated that TXS could react with Iod through an electron transfer reaction through its excited states, leading to the formation of radical initiating species. Interestingly, the TXS/Iod was demonstrated to be an efficient photoinitiating system for free-radical (FRP) and cationic (CP) polymerization under LEDs@385, 405, and 455 nm. In particular, whatever the epoxy monomer mixtures used, remarkable final epoxy conversions were achieved up to 100% under air. In this latter case, we demonstrated that both the photoinduced sol-gel process (hydrolysis of trimethoxysilane groups) and the cationic photopolymerization occurred simultaneously.

Effect of surface modification of nanosilica by hydride-groups on morphology, strength and resistance of epoxy-composites

A chemical modification of fumed silica surface by active groups can enlarge its functional capabilities as a polymer filler. As a result, a new possibility in the formation of reinforced polymeric composites appears.In this work, silica with grafted silicon hydride (≡Si–H) groups was found to be active in the processes of hydrosilylation of active bonds in monomers during their polymerization. Hydride-silylated silica was obtained via his treatment with triethoxysilane. The presence of grafted silicon hydride groups was confirmed by means of IR spectroscopy, and their concentration measured by titrimetric and spectrophotometric analysis was found to be about 0.4 mmol/g. Silica-epoxy composites were prepared and the resulted materials after curing were subject to compression, bending, micro-hardness and adhesion mechanical tests.According to experimental results, the synthesized hydride-silica fillers let to enhance the important strength properties of the epoxy-polymer already at 2 wt% loading. In particular, the elastic modulus for compression increased by 30–40%, the one for bending – by 1.2–1.5 times, the flexural strength – by 1.5–2 times, and adhesion to steel – by 2.5–2.8 times. These effects are achieved due to good compatibility and homogeneous distribution of the filler in the resin, as shown by SEM microscopy (after hydride-modification, the silica agglomerates in epoxy disappear). IR-spectroscopy shows a possible increasing of epoxy conversion's rate after 2%-filling by hydride-silica. Thus, preliminary results indicate that fumed silica with grafted silicon hydride groups shows promise as active reinforcing filler for epoxy polymers.The work demonstrates the potential of nanosilica filler surface hydride-silylation for low-cost strengthening of epoxy polymers for industry and repair.

Detection of kissing bond type defects and evaluation of the bonding quality in metal/adhesive/composite structures by a wavenumber-frequency insensitive SH mode

This work focuses on the non-destructive evaluation of the bonding quality in different metal/adhesive/composite samples and on the detection of defects simulating a kissing bond, using Shear Horizontal (SH) guided waves. A predictive 2D numerical model, called interphases model and based on finite elements method describing the interface substrate/adhesive by a very thin layer, is developed. Various samples with different adhesion levels obtained by modifying the cohesive and adhesive aspects or including a defect representing a kissing bond are investigated. An experimental study is performed with non-contact ElectroMagnetic Acoustic Transducers (EMAT) in excitation and reception. As the wavenumber-frequency sensitive SH modes to the adhesion quality shown by the numerical predictions are not easy to generate experimentally, the analysis of the behaviour of the SH modes is based here on their amplitude. Results show that it is possible to differentiate between the adhesion levels due to different epoxy conversion, the presence or absence of an adhesion promoter or a pollution by a release agent, as well as the detection of the defect.

Lanthanide and Ladder-Structured Polysilsesquioxane Composites for Transparent Color Conversion Layers

Ladder-type polysilsesquioxanes (LPSQs) containing phenyl as a high refractive index unit and cyclic epoxy as a curable unit were found to be excellent candidates for a transparent color conversion layer for displays due to being miscible with organic solvents and amenable to transparent film formation. Therefore, the LPSQs were combined with luminescent lanthanide metals, europium Eu(III), and terbium Tb(III), to fabricate transparent films with various emission colors, including red, orange, yellow, and green. The high luminescence and transmittance properties of the LPSQs-lanthanide composite films after thermal curing were attributed to chelating properties of hydroxyl and polyether side chains of LPSQs to lanthanide ions, as well as a light sensitizing effect of phenyl side chains of the LPSQs. Furthermore, Fourier-transform infrared (FT-IR) and X-ray photoelectron spectroscopy and nanoindentation tests indicated that the addition of the nanoparticles to the LPSQs moderately enhanced the epoxy conversion rate and substantially improved the wear resistance, including hardness, adhesion, and insusceptibility to atmospheric corrosion in a saline environment. Thus, the achieved LPGSG-lanthanide hybrid organic-inorganic material could effectively serve as a color conversion layer for displays.

Investigation and assessment of epoxy resin adhesives using Fourier‐transform infrared spectrometry

AbstractEpoxy resin adhesives are very attractive for many industries, especially in the aerospace and automotive industries because they eliminate heavy connection elements, such as bolts and screws, and reduce the total weight. This study assesses developed epoxy resin adhesives using Fourier‐transform infrared spectrometry. The curing reaction between Epikote 828 epoxy resin and Epikure polyamidoamine curing agent 3090, and the chemical structure of the additives (CAB‐O‐SIL TS‐720) used for rheology control and six different types of fillers (calcite with particle diameters of 700 nm, 5 μm, and 10 μm, coated calcite with a particle diameter of 900 nm, and barite and calcite with a particle diameter of 5 μm) employed in the adhesives are investigated. The Fourier‐transform infrared spectrometry results of the epoxy resin and curing agent demonstrate that 83.5 % epoxy conversion is achieved at a temperature of 25 °C. The chemical composition of the additives with six different types of fillers and 1 %, 3 %, and 5 % additions of CAB‐O‐SIL TS‐720 prepared in both nujol mull and potassium bromide discs is characterized using Fourier‐transform infrared spectrometry. The potassium bromide discs yield higher intensities owing to good packing of cubic particles of potassium bromide with nano particle size CAB‐O‐SIL TS‐720 and all filler types.

Effect of Copolymer on the Wrinkle Structure Formation and Gloss of a Phase-Separated Ternary Free-Radical/Cationic Hybrid System for the Application of Self-Matting Coatings.

Hybrid free-radical/cationic systems can generate phase-separated polymers or interpenetrating networks driven by photopolymerization. In this study, phase separation of a ternary mixture composed of a polybutadiene urethane diacrylate (PBUDA), a cycloaliphatic diepoxyde (CE), and hexanediol dimethacrylate (HDDMA) was investigated. Using systematic variations of the initial composition of the mixture, a miscibility phase diagram of the ternary mixture was established. Based on this diagram, a reactive copolymer (poly(butyl acrylate-co-glycidyl methacrylate) (PBGMA)) was introduced in a reference hybrid system to manipulate the crosslinking network, polymer morphology, and properties (e.g., roughness, gloss, strain at break, and glass transition temperature Tg). When cured as a coating, the ternary hybrid system showed a depthwise gradient of epoxy conversion, and thereby developed a mostly cured skin above a viscous sublayer of uncured monomer. This skin can develop compressive stress due to the swelling from the diffusion of unreacted monomers beneath, and if the compressive stress is significantly high, wrinkles appear on the coating’s surface. This work highlights how both skin thickness and elastic modulus impact wrinkle frequency and amplitude. It was demonstrated that these wrinkle parameters can be manipulated in the ternary system by the addition of PBGMA. We also demonstrated that by employing UV irradiation and varying the PBGMA content, it is possible to engineer coatings that range from smooth surfaces with high gloss to wrinkled topographies with a very low associated gloss.

Sintesis Senyawa-Senyawa Epoksi dari Asam Lemak Minyak Nyamplung (Calophyllum inophyllum L.)

Epoxidation is a reaction of a carbon double bond with active oxygen, which results in the addition of an oxygen atom, converting the original double bond into a three-membered epoxide (oxirane) ring. Generally, the raw material for making epoxy comes from petroleum. Nyamplung kernel oil is a non-edible oil that can be used as an alternative raw material for making epoxy derivatives. The purpose of this study was to determine the optimum conditions and characterization of epoxy materials. The fatty acids of Nyamplung kernel oil were reacted formic acid and hydrogen peroxide with sulfuric acid as a catalyst. The optimum condition of the following parameters on the study of this process was investigated: the epoxidation time, temperature, and the mole ratio of formic acid and hydrogen peroxide. The results showed that the optimum reaction conditions with the temperature was 65 oC, the mole ratio of formic acid and hydrogen peroxide was 1:6, and the reaction time was 75 minutes. The results of the characterization under optimum conditions showed the oxirane value of 1.69, the iodine number of 9.63 mg iod/100 g, and the epoxy conversion of 67.6 %. The results of FTIR characterization showed absorption at a wavenumber of 820.03 cm-1 which is a specific absorption from the oxirane ring of the epoxy compound.

Effect of epoxy resin content and conversion rate on the compatibility and component distribution of epoxy asphalt: A MD simulation study

Molecular dynamics simulation technology was introduced into the characterization of epoxy asphalt performance, to display the reaction process between the epoxy resin and curing agent in epoxy asphalt clearly and explore the influence of epoxy resin content and conversion rate on the epoxy asphalt performance containing thermodynamic, compatibility, component distribution and diffusion. The reaction between the epoxy resin and curing agent was realized through Perl script, and epoxy asphalt molecular dynamics models with different resin content (25%, 45%, and 65%), and various conversion rates were prepared. Results demonstrated that the addition of epoxy resin enhanced the low-temperature performance of epoxy asphalt, but the increase in conversion rate played a negative impact on low-temperature performance. The CED and solubility parameter were synergistically affected by the epoxy resin content and conversion rate. Furthermore, the raise in the content of epoxy resin was the main reason for enhancing the compatibility between epoxy resin and asphalt. Therefore, the reasonable control of the resin content and conversion rate was beneficial to enhance the stability of the epoxy asphalt system and improve the compatibility between the resin phase and the asphalt phase. 25%-EA and 45%-EA were considered as asphalt phase materials. Aggregation behaviors exhibited between asphaltenes, and adsorption behaviors presented between epoxy resin and asphaltene. With the increase of conversion rate, the adsorption behavior gradually disappeared. 65%-EA belonged to the resin phase material, and the aggregation between asphaltenes was diminished. In addition, the epoxy resin without conversion reaction had the smooth diffusion behavior in epoxy asphalt.

A class of azocarbazole‐based carboxylates: High‐efficiency ionic unimolecular photobase generators for thiol‐epoxy click polymerization under blue light

AbstractTwo new unimolecular azocarbazole‐based visible photobase generators (Ac‐C‐Base) with different strong bases such as 1,5,7‐triazabicyclo[4.4.0]dec‐5‐ene (TBD) and 1,1,3,3‐tetramethylguanidine (TMG) as the potential active species were prepared. Their structures were confirmed by 1H NMR, 13C NMR, and HR‐MS. According to the photolysis and EPR results, Ac‐C‐Base could generate free radicals and strong bases simultaneously through the photodecarboxylation mechanism under 455 nm LED irradiation. Thus they can effectively catalyze the thiol‐epoxy polymerization without post exposure baking under light exposure. In addition, the Ac‐C‐TBD containing a stronger base shows a faster polymerization rate and higher epoxy conversion.

Visible light-induced cationic photopolymerization by diphenyliodonium hexafluorophosphate and benzothiadiazole dyes

New benzothiadiazole-based long-wavelength organic dyes (Y-1 and Y-2) were prepared for effectively sensitizing diphenyliodonium hexafluorophosphate (IOPF) to initiate the fast curing of bisphenol-A epoxy resin (E51) under visible light, avoiding traditional UV light sources that have high energy and high radiation. Y-1 and Y-2 have absorption spectra extended to more than 550 nm. By using Y-1 and Y-2 as photosensitizers for IOPF, E51 reach high epoxy conversions of 95% under light wavelength of 470-nm irradiation. IOPF and benzothiadiazole dyes present at the same time show good visible-light initiating activity. The high curing conversions are attributed to the photoelectron transfer reaction between diphenyliodonium hexafluorophosphate and benzothiadiazole dyes, based on our photochemical and electrochemical experiments. In addition, the terminated groups or of Y-1 (–F) and Y-2 (–OCH3) have a great influence on the photopolymerization rate of the curing systems and thermal properties of E51 after cured. In addition, E51 was even polymerized about 70% in the presence of 510-nm light filter.

Visible-light photopolymerization of epoxy-terminated poly(dimethylsiloxane) blends: Influence of the cycloaliphatic monomer content on the curing behavior and network properties

Siloxane-based networks were obtained by photoinitiated cationic ring-opening polymerization of mixtures composed of two different siloxane monomers: poly(dimethylsiloxane) diglycidyl ether (PDMS-DGE) and bis [2-(3,4-epoxycyclohexyl) ethyl]-tetramethylsiloxane (ECE-TMA). The photoinitiated polymerization of PDMS-DGE is very sluggish and thus finds little use in high-speed photocuring applications. However, this monomer undergoes fast visible-light photopolymerization when combined with ECE-TMA. This behavior was ascribed to copolymerization effects induced for the higher reactivity of the cycloaliphatic epoxy monomer (ECE-TMA). It was demonstrated that the polymerization rate, as well as the thermo-mechanical properties of the resulting networks, can be adjusted by varying the ratio between both monomers. Plots of PDMS-DGE conversion versus ECE-TMA conversion evidenced a non-ideal copolymerization behavior, with a preferential addition of ECE-TMA units during the first stages of network formation. The composition of the mixture was varied over the entire range of concentrations without evidence of phase separation before or during photopolymerization at room temperature. The resulting networks exhibited a behavior that changed from a rubbery to a glassy state at room temperature depending on the mixture composition, as revealed by dynamic mechanical analysis. The storage modulus and damping factor were successfully correlated with the crosslinking density and network topology. The high transparency of the mixtures allowed to reach a high epoxy conversion by photopolymerization, even for thick samples (1–2 mm in thickness), which constitutes a significant advance for applications requiring high-speed curing protocols at ambient conditions.

Improvement on curing performance and morphology of E5I/TPGDA mixture in a free radical-cationic hybrid photopolymerization system

A visible light-induced free radical-cationic hybrid photopolymerization system co-initiated by diphenyliodonium hexafluorophosphate (IOPF) and diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO). IOPF and TPO rapidly induced a mixture of diglycidyl ether of bisphenol-A epoxy resin (E51) and tripropylene glycol diacrylate (TPGDA) under a halogen lamp (λ = 380–580 nm). The curing rate of epoxy resin is significantly accelerated. The effect of weight ratio of IOPF/TPO, proportion of E51/TPGDA, benzoyl peroxide (BPO), 3,4-epoxycyclohexylmethyl-3′,4’epoxycyclohexyl carboxylate (ERL4221) on IOPF/TPO/TPGDA/E51 hybrid systems (HSs1–11) were studied by near infrared (NIR) spectroscopy. Free radical and cationic photopolymerization for TPO/TPGDA and IOPF/TPO/E51 were also investigated. TPO shows a sensitization effect to accelerate the curing of E51. Scanning electron microscopy (SEM) was used to observe the morphology of cured films, including surface and cross section. The film of hybrid system with BPO (HS-6) has the advantage of smooth surface and uniform cross section, while that of free radical system is obviously plicate. The acceleration of epoxy conversion is up to 85%, when ERL4221 was added.

Experimental Study on the Micromorphology and Strength Formation Mechanism of Epoxy Asphalt During the Curing Reaction

The micromorphological changes and the strength formation mechanism of the curing of epoxy asphalt, which is mostly used for steel bridge deck pavements, were investigated. A tensile test was used to analyze the mechanical properties of epoxy asphalt, and Fourier transform infrared spectroscopy (FTIR) was used to determine the change in the epoxy peak area. Laser scanning confocal microscopy (LSCM) and scanning electron microscopy (SEM) were used to observe two-dimensional and three-dimensional micromorphological changes, respectively, during the curing reaction of epoxy asphalt. The results of the tensile and FTIR tests on epoxy asphalt showed that the tensile strength and epoxy conversion rate both increased with the curing time and exhibited similar trends, indicating that the network formed by the crosslinking and polymerization of epoxy groups causes the increased strength of epoxy asphalt. The curing degree of epoxy asphalt during the curing reaction can be indirectly evaluated from the conversion rate of epoxy groups. The asphalt tended to evenly be dispersed in the continuous phase of the epoxy resin during the formation of the epoxy resin network, and the network structure increased the deformation of the epoxy resin. The epoxy asphalt curing reaction process was classified into three stages based on the degree of curing.

Influence of temperature and BN nanoparticles on UV, thermal and dark curing of a cycloaliphatic epoxy resin

The influence of boron nitride (BN) nanoparticles on cationic photopolymerization of an epoxy resin at different temperatures was investigated employing photo-DSC. A difunctional cycloaliphatic epoxy resin was polymerized in the presence of triarylsulfonium hexafluoroantimonate salts (cationic photoinitiator). BN-epoxy dispersions containing 5 mass% of BN were obtained by sonication. The epoxy conversion during UV irradiation was determined at seven temperatures, from 30 to 90 °C. The conversion reached was strongly dependent on temperature, and lower conversions were obtained in the presence of BN. After the UV curing, the samples were thermally postcured by dynamic heating in the DSC. The thermal postcuring shows two exothermal peaks, being the main one dependent on the temperature of the previous UV curing and on the composition. The total achieved conversion (65–77%) is lower for the samples containing BN compared to neat epoxy. The UV-irradiated samples at 40 °C reached conversions between 24 and 36%; afterward, they were kept under isothermal dark curing (40 °C) up to 1 month leading to significant conversion increases, independently of the composition and reaching a final conversion between 60 and 70%. DMTA measurements of dark-cured specimens evidence a heterogeneous epoxy matrix, thus needing higher postcuring temperatures to get homogeneity. The Tg of the epoxy matrix is reduced in the presence of BN nanoparticles.

Effect of silica fume and rice husk silica in bio-epoxy composites

The plastic industry is having a rising interest in using bio-resin materials and waste materials for high performance applications. This research assesses the effect of two types of silica in the thermo-mechanical properties and curing behavior of bio-based epoxy composites. Bio-silica (B.S.), obtained from rice husk in our laboratories, and silica fume (S.F.), Aerosil 150, have been used for the development of these composites. An aliphatic epoxy resin, based on Sorbitol Glycidyl Ether (GE60), was crosslinked with two polyetheramine hardeners having oxypolyethylene (PEO) and oxypropylene (PPO) repeating units in the backbone, respectively. The bio-based aliphatic epoxy composites were prepared by a solventless procedure and were cured at room temperature. In general, the epoxy amine systems were reinforced with 3 wt% of both silicas (B.S. and S.F.). The degree of silica dispersion, thermo-mechanical properties and curing monitoring of the composites were analyzed by several techniques described in the paper. The thermal stability increased in both filled networks, but a remarkable improvement in the GE60/PEO/3BS system was observed when compared to S.F. composites. Besides, mechanical properties were also enhanced in the SGE/PEO/3BS system, with 25% of improvement in the Young Modulus and Tensile Strength respect to the other systems. However, the S.F. composites showed a more significant percentage of epoxy conversion when compared with epoxy-biosilica networks. The higher hydrophilicity of PEO was relevant in terms of B.S. dispersion, kinetic reactions, and thermo-mechanical performance.

A Visible-Light Curing system of Diphenyliodonium Salt/BODIPY dyes/Bisphenol-A Epoxy Resin Under Halogen Lamp

Bisphenol-A epoxy resin have attracted much attention due to its good mechanical properties after curing. In this paper, a visible light curing system of bisphenol-A epoxy resin (E51) initiated by diphenyliodonium hexafluorophosphate (IOPF) and boron dipyrromethene-based (BODIPY) photosensitizers (BODIPY-1 and (BODIPY-2) under a halogen lamp (380-580 nm) was investigated. BODIPY dyes are well known long-wavelength photosensitizers, which is good for IOPF to expand absorption to visible light region. BODIPY-1 and BODIPY-2 are intermediates that reported in our previous work. When IOPF/BODIPY-1 is 2wt%/1wt%, E51 achieves epoxy conversion up to 60% in 0.18 mm thick molds. The Illumination of the halogen lamp is as low as 25.0 mW/cm2. Under same condition, the epoxy conversions of IOPF/BODIPY-2/E51 and IOPF/E51 are about 50% and 20%. When filters were used, IOPF/BODIPY/E51 was effectively cured under light irradiation of 460 nm and 540 nm, and only IOPF is not able to initiate E51 at these wavelengths.

Effect of Reaction Time and Catalyst Concentration on Making of Epoxy Compounds Using Sulphuric Acid Catalyst Based on Crystallized Palm Fatty Acid Distillate

Epoxy is produced from an epoxidation reaction of vegetable oils such as linseed oil, corn oil, palm oil or natural oils that have unsaturated bonds. The aim of this research is to produce epoxy compound based on Crystallized Palm Fatty Acid Distillate. First, the gas chromatography analysis was done to the palm fatty acid distillate. Then, before the epoxidation reaction began, crystallization process was done based on solubility of saturated and unsaturated fatty acid in organic solvent (methanol). In this research, the Crystallized Palm Fatty Acid Distillate that has reacted with acetic acid glacial and hydrogen peroxide, toluene as solvent, sulfuric acid as a catalyst in a three-neck flask fitted with condenser reflux at 700C and stirred at 500 rpm. The catalyst concentration varied from 1.5%, 2.0%, 2.5%, 3.0% and 3.5% and epoxidation reaction time varied from 60 minutes, 120 minutes, 180 minutes, 240 minutes and 300 minutes. The results showed that the highest epoxy conversion was achieved at reaction time of 120 minutes with 2.5% sulfuric acid catalyst concentration against the amount of hydrogen peroxide and acetic acid used. The result of this analysis shows that oxirane oxygen content is 0.96%, iodine number is 17,16g iod / 100 g oil and conversion equal to 81,61%.

Facile method to prepared photoinitiated cationic curable plant oil and its enhancement on the impact strength of cycloaliphatic diepoxide

In this study, a modified soybean oil (SBO) with urethane branched chain terminated by epoxy group (SBO-URE) was prepared by highly efficient thiol-ene photo-click chemistry and isocyanate polyurethane reaction. The structure of modified plant oil was characterized by FT-IR and 1H-NMR. Then, the obtained bio-resin was blended with a petroleum-based cycloaliphatic epoxy 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate (ECC) with different composition ratios. The photoinitiated cationic process and properties of curing formulation were investigated. The epoxy conversion was improved by adding chlorothioxanthone (CTX) through photosensitization process of onium salts. The DMA, TGA, and a series of tensile tests indicated that the addition of SBO-URE can increase the impact resistance with a modest decrease of tensile properties without sacrificing thermal stability. The formulation system exhibited a better performance than the formulation with its commercial counterpart epoxidized soybean oil (ESO), thereby revealing that the introduction of urethane branched structure terminated by epoxy group of soybean oil can react with epoxy matrix during curing process, and offered a certain improvement of impact strength without serious depletion of tensile properties.