Structure and properties of amine‐hardened epoxy/benzoxazine hybrids: Effect of epoxy resin functionality

Bifunctional, trifunctional, and tetrafunctional epoxy resins (EP) were hardened with stoichiometric amount of 4,4′‐diaminodiphenyl methane in presence and absence of benzoxazine (BOX). The EP/BOX ratio of the hybrid systems was 100/0, 75/25, 50/50, and 25/75 wt %, respectively. Information on the structure of the hybrid systems was received from differential scanning calorimetry, dynamic‐mechanical thermal analysis, atomic force microscopy, and fractographic studies. The flexural and fracture mechanical properties of the EP/BOX hybrids were determined and compared to those of the reference EPs. The thermal degradation and fire resistance of the hybrids were also studied. It was found that the polymerized BOX was built in the network in from of nanoscale inclusions and acted as antiplasticizer. Incorporation of BOX enhanced the flexural modulus and strength and reduced the glass transition temperature of the parent EP. The fracture toughness and energy were practically not improved by hybridization with BOX. The charring and flame resistance were improved with increasing amount of BOX in the EP/BOX hybrids. The relative improvement in the latter was most prominent for the bifunctional EP/BOX systems. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Synthesis and characterization of fluorinated poly(etherimide)s toughening for carbon fiber‐reinforced epoxy composites

Novel‐fluorinated poly(etherimide)s (FPEIs) with controlled molecular weights were synthesized and characterized, which were used to toughen epoxy resins (EP/FPEI) and carbon fiber‐reinforced epoxy composites (CF/EP/FPEI). Experimental results indicated that the FPEIs possessed outstanding solubility, thermal, and mechanical properties. The thermally cured EP/FPEI resin showed obviously improved toughness with impact strength of 21.1 kJ/m² and elongation at break of 4.6%, respectively. The EP/FPEI resin also showed outstanding mechanical strength with tensile strength of 91.5 MPa and flexural strength of 141.5 MPa, respectively. The mechanical moduli and thermal property of epoxy resins were not affected by blending with FPEIs. Furthermore, CF/EP/FPEI composite exhibited significantly improved toughness with Mode I interlaminar fracture toughness (G_IC) of 899.4 J/m² and Mode II interlaminar fracture toughness (G_IIC) of 1017.8 J/m², respectively. Flexural properties and interlaminar shear strength of the composite were slightly increased after toughening. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers     

Synthesis of EP‐POSS mixture and the properties of EP‐POSS/epoxy,SiO2/epoxy,and SiO2/EP‐POSS/epoxy nanocomposite

The hybrid material of EP‐POSS mixture was synthesized by the hydrolysis and condensation of (γ‐glycidoxypropyl) trimethoxysilane. A series of binary systems of EP‐POSS/epoxy blends, epoxy resin modified by silica nanoparticles (SiO₂/epoxy), and ternary system of SiO₂/EP‐POSS/epoxy nanocomposite were prepared. The dispersion of SiO₂ in the matrices was evidenced by transmission electron micrograph, and the mechanical properties, that is, flexural strength, flexural modulus, and impact strength were examined for EP‐POSS/epoxy blends, SiO₂/epoxy, and SiO₂/EP‐POSS/epoxy, respectively. The fractured surface of the impact samples was observed by scanning electron micrograph. Thermogravimetry analysis were applied to investigate the different thermal stabilities of the binary system and ternary system by introducing EP‐POSS and SiO₂ to epoxy resin. The results showed that the impact strength, flexural strength, and modulus of the SiO₂/EP‐POSS/epoxy system increased around by 57.9, 14.1, and 44.0% compared with the pure epoxy resin, T_i, T_max and the residues of the ternary system were 387°C, 426°C, and 25.2%, increased remarkably by 20°C, 11°C and 101.6% in contrast to the pure epoxy resin, which was also higher than the binary systems. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 810‐819, 2013     

Enhanced fracture toughness of epoxy resins with novel amine‐terminated poly(arylene ether sulfone)–carboxylic‐terminated butadiene‐acrylonitrile–poly(arylene ether sulfone) triblock copolymers

Amine‐terminated poly(arylene ether sulfone)–carboxylic‐terminated butadiene‐acrylonitrile–poly(arylene ether sulfone) (PES‐CTBN‐PES) triblock copolymers with controlled molecular weights of 15,000 (15K) or 20,000 (20K) g/mol were synthesized from amine‐terminated PES oligomer and commercial CTBN rubber (CTBN 1300x13). The copolymers were utilized to modify a diglycidyl ether of bisphenol A epoxy resin by varying the loading from 5 to 40 wt %. The epoxy resins were cured with 4,4′‐diaminodiphenylsulfone and subjected to tests for thermal properties, plane strain fracture toughness (K_IC), flexural properties, and solvent resistance measurements. The fracture surfaces were analyzed with SEM to elucidate the toughening mechanism. The properties of copolymer‐toughened epoxy resins were compared to those of samples modified by PES/CTBN blends, PES oligomer, or CTBN. The PES‐CTBN‐PES copolymer (20K) showed a K_IC of 2.33 MPa m^0.5 at 40 wt % loading while maintaining good flexural properties and chemical resistance. However, the epoxy resin modified with a CTBN/8K PES blend (2:1) exhibited lower K_IC (1.82 MPa m^0.5), lower flexural properties, and poorer thermal properties and solvent resistance compared to the 20K PES‐CTBN‐PES copolymer‐toughened samples. The high fracture toughness with the PES‐CTBN‐PES copolymer is believed to be due to the ductile fracture of the continuous PES‐rich phases, as well as the cavitation of the rubber‐rich phases. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1556–1565, 2002; DOI 10.1002/app.10390     

Mechanical characterization of woven carbon fiber composites with poly(methyl methacrylate)–modified epoxy matrices

The influence of the modification of epoxy matrices with poly(methyl methacrylate) (PMMA) on the fracture behavior of composite laminates based on woven carbon fibers has been investigated. Three‐point flexural, short beam shear (SBS) and end‐notched flexural tests (ENF) have been carried out. Microstructural features have been investigated by atomic force microscopy (AFM) and scanning electron microscopy (SEM). Dynamic mechanical thermal analysis of the different epoxy matrices and their corresponding composites shows the power of this technique for microstructural studies. Fracture behavior is compared with that shown by similar bifunctional (DGEBA) epoxy matrix composites. In spite of the two‐phase structure obtained in tetrafunctional (TGDDM) epoxy matrix‐based systems for all PMMA contents, only a small improvement in fracture toughness and interlaminar shear strength properties was obtained. In contrast, for DGEBA bulk matrices and composites, a higher enhancement of fracture toughness was obtained, as a consequence of the lower crosslink densities of bifunctional matrices.     

Use of hygrothermal decomposed polyester–urethane waste for the impact modification of epoxy resins

Hygrothermally decomposed polyurethane (HD‐PUR) of a polyester type was used as an impact modifier in tri‐ and tetrafunctional epoxy (EP) resins. Between 5 and 80 wt % of the PUR modifier was added to the EP prior to its crosslinking with a diamine compound (diaminodiphenyl sulfone, DDS). The mean molecular weight between crosslinks (M_c ) was determined from the rubbery plateau modulus of the dynamic mechanical thermal analysis (DMTA) spectra. The fracture toughness (K_c) and energy (G_c) of the modified resins were determined on static‐loaded compact tension (CT) specimens at ambient temperature. The change in the K_c and G_c as a function of M_c followed the prediction of the rubber elasticity theory. The efficiency of the HD‐PUR modifier was compared with that of a carboxyl‐terminated liquid nitrile rubber (CTBN). Attempts were also made to improve the functionality of the modifier by hygrothermal decomposition of PUR in the presence of glycine and ε‐caprolactam, respectively. DMTA and fractographic results showed that HD‐PUR functions as an active diluent and a phase‐separating additive at the same time. As HD‐PUR can be regarded as an amine‐functionalized rubber, it was used as the hardener (by replacing DDS) in some EP formulations. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 1139–1151, 2000     

Toughness response of vinylester/epoxy‐based thermosets of interpenetrating network structure as a function of the epoxy resin formulation: Effects of the cyclohexylene linkage

Vinylester/epoxy (VE/EP)‐based thermosets of interpenetrating network (IPN) structures were produced by using a VE resin (bismethacryloxy derivative of a bisphenol A–type EP resin) with aliphatic (Al‐EP) and cycloaliphatic (Cal‐EP) EP resins. Curing of the EP resins occurred either with an aliphatic (Al‐Am) or cycloaliphatic diamine compound (Cal‐Am). Dynamic mechanical thermal analysis (DMTA) and atomic force microscopy (AFM) suggested the presence of an interpenetrating network (IPN) in the resulting thermosets. Fracture toughness (K_c) and fracture energy (G_c) were used as the toughness characterization parameters of the linear elastic fracture mechanics. Unexpectedly high K_c and G_c data were found for the systems containing cyclohexylene units in the EP network, such as VE/Al‐EP+Cal‐Am and VE/Cal‐EP+Al‐Am. This was attributed to the beneficial effects of the conformational changes of the cyclohexylene linkages (chair/boat), which were closely analogous to those in some thermoplastic copolyesters. The failure mode of the VE/EP thermoset combinations was studied in scanning electron microscopy (SEM) and discussed. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2124–2131, 2003     

The effect of amine/epoxy ratio on the fracture toughness of tetrafunctional epoxy resin

Summary. The effect of amine/epoxy ratio on the fracture toughness (K_Ic) of tetrafunctional epoxy resin was investigated. K_Ic value was measured by single-edge notch-bend test. The K_Ic value of the tetrafunctional epoxy resin increased with increasing the amount of amine curing agent. This result was explained with the structural viewpoint of the epoxy network. The network structure of the tetrafunctional epoxy was analyzed with dynamic thermomechanical measurement and in-situ near IR technique. Received: 19 June 1997/Accepted: 17 Juli 1997     

Tertiary‐amine‐free,non‐planar,sulfone‐containing,tetrafunctional epoxy and its application as a high temperature matrix

Non‐amine‐derived tetrafunctional epoxies have several advantages over the amine‐derived N,N,N′,N′‐tetraglycidyl‐4,4′‐diaminodiphenyl methane (TGDDM) in high temperature applications. Although two non‐amine‐derived tetrafunctional epoxies were developed in our laboratory, further improvements in toughness using less loading amount is still desirable. Thus, a tertiary‐amine‐free, non‐planar and triphenylmethane‐containing tetrafunctional epoxy (STFE) with a sulfone spacer was synthesized. When it was mixed with diglycidyl ether of bisphenol A (DGEBA) and cured with 4,4′‐diaminodiphenylsulfone (DDS), both thermal and mechanical performances outperformed TGDDM. Moreover, STFE modified system shows the highest toughness (35.7 kJ m^–2) among three amine‐free and triphenylmethane‐containing epoxies at merely 5 wt% loading. Molecular simulation and thermomechanical analysis results suggest that the improved mechanical properties could be related to the geometry of the molecule and larger free volume. Despite a marginal drop in T_g, the thermal degradation temperature is better than that of TGDDM/DDS. In addition, the moisture resistance of STFE/DGEBA/DDS is much better than that of TGDDM/DDS. Thus, STFE modified DGEBA could be a potential replacement for TGDDM in some high temperature applications. © 2020 Society of Chemical Industry     

The effects of polyamic acid on curing behavior,thermal stability,and mechanical properties of epoxy/DDS system

A thermoplastic modification method was studied for the purpose of improving the toughness and heat resistance and decreasing the curing temperature of the cured epoxy/4, 4′‐diaminodiphenyl sulfone resin system. A polyimide precursor‐polyamic acid (PAA) was used as the modifier which can react with epoxy. The effects of PAA on curing temperature, thermal stability and mechanical properties were investigated. The initial curing temperature (T_i) of the resin with 5 wt % PAA decreased about 50°C. The onset temperature of thermal decomposition and 10 wt %‐weight‐loss temperature for the resin system containing 2 wt % PAA increased about 60°C and 15°C respectively. Besides, the value of impact toughness and plain strain fracture toughness for the modified epoxy resin increased ～ 190% and 55%, respectively. Those changes were attributed to the outstanding thermal and mechanical properties of polyimide, and more importantly to formation of semi‐interpenetrating polymer networks composed by the epoxy network and linear PAA. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Toughening of epoxy resins with aromatic polyesters

Polyesters, prepared by direct polycondensation from bisphenol A and aliphatic dicarboxylic acids [adipic acid (AD), suberic acid, sebacic acid (SE), and dodecanedioic acid], were used to improve the toughness of the diglycidyl ether of the bisphenol A/diaminodiphenyl methane epoxy system. Polyesters had the number average molecular weight (M_n) ranging from 4300 to 19,200 g/mole. The epoxy systems modified with the AD system (M_n = 6400 g/mole) and the SE system (M_n = 10,200 g/mole) showed phase separated structures with discrete domains of 0.2 μm, but other systems showed smooth fracture surfaces when observed by scanning electron microscopy. The modified epoxy systems except for the AD system and SE system showed two tan δ peaks corresponding to the α and β transitions of the epoxy resin. The modified epoxy systems showed maximum values of K_1c at around 10 wt % of polyester and maximum flexural properties at 5 wt % of polyester. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 2464–2473, 2000     

Effect of polyarylene ether nitriles on processing and mechanical behaviors of phthalonitrile‐epoxy copolymers and glass fiber laminated composites

A series of copolymers and glass fiber composites were successfully prepared from 2,2‐bis [4‐(3,4‐dicyanophenoxy) phenyl] propane (BAPh), epoxy resins E‐44 (EP), and polyarylene ether nitriles (PEN) with 4,4′‐diaminodiphenyl sulfone as curing additive. The gelation time was shortened from 25 min to 4 min when PEN content was 0 wt % and 15 wt %, respectively. PEN could accelerate the crosslinking reaction between the phthalonitrile and epoxy. The initial decomposition temperatures (T_i) of BAPh/EP copolymers and glass fiber composites were all more than 350°C in nitrogen. The T_g of 15 wt % PEN glass fiber composites increased by 21.2°C compared with that of in comparison with BAPh/EP glass fiber composite. The flexural strength of the copolymers and glass fiber composites reached 119.8 MPa and 698.5 MPa which increased by 16.6 MPa and 127.3 MPa in comparison with BAPh/EP composite, respectively. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Rubber modification of low temperature cure cyanate ester matrices and the performance in glass fabric composites

Low temperature cure cyanate ester resin systems were developed and modified with epoxy‐terminated butadiene acrylonitrile rubber (ETBN) and impregnated into woven glass fabric. Mode I and mode II interlaminar fracture toughness values of the cured laminates were evaluated as a function of rubber concentration. Mode I fracture toughness increased to almost twice that of the unmodified system, while mode II fracture toughness remained essentially unchanged. Composite samples were subjected to aging experiments in water and the absorption/desorption behavior was investigated as was the effect on thermal performance. The presence of rubber was found to reduce the rate of matrix deterioration but also caused a substantial increase in water uptake. It was found that although the addition of rubber to the matrices decreased the unconditioned (dry) T_g all specimens showed the same reduction in T_g, after equilibrium water absorption.     

Toughening of epoxy systems by brominated epoxy

Blends of brominated epoxy (BE) and conventional epoxy resins were studied following curing with aliphatic triethylenetetramine (TETA), etheric (polyether diamine‐ PEA4), and aromatic (3,3′‐diamino diphenyl sulfone [DDS]) hardeners. The addition of BE resulted in an increase in T_g in all tested blends. Blends with 50 wt% BE cured with TETA demonstrated an increase in flexural modulus and flexural strength, while preserving the elongation. Blends with 40 wt% BE cured with PEA4 and 50 wt% BE cured with DDS resulted in a significant enhanced tensile elongation. The shear strength of all cured systems decreased moderately with the addition of BE exhibiting a mixed mode failure. Analysis of the fracture morphology using electron microscopy supported the increase of toughness levels as a result of incorporating BE to conventional epoxy. A unique nodular and rough fracture morphology was obtained, which is related to a toughening mechanism caused by the addition of BE. It was concluded that blends of BE and conventional epoxy could be used as structural adhesives having high T_g, enhanced mechanical properties and increased toughness. POLYM. ENG. SCI., 59:206–215, 2019. © 2018 Society of Plastics Engineers     

Morphology, thermal relaxations and mechanical properties of layered silicate nanocomposites based upon high-functionality epoxy resins

This paper investigates the possibility of improving the mechanical properties of high-functionality epoxy resins through dispersion of octadecyl ammonium ion-modified layered silicates within the polymer matrix. The different resins used are bifunctional diglycidyl ether of bisphenol-A (DGEBA), trifunctional triglycidyl p-amino phenol (TGAP) and tetrafunctional tetraglycidyldiamino diphenylmethane (TGDDM). All resins are cured with diethyltoluene diamine (DETDA). The morphology of the final, cured material was probed by wide-angle X-ray scattering, as well as optical and atomic force microscopy. The α- and β-relaxation temperatures of the cured systems were determined using dynamic mechanical thermal analysis. It was found that the presence of organoclay steadily decreased both transition temperatures with increasing filler concentration. Further, the effect of different concentrations of the alkyl ammonium-modified layered silicate on the toughness and stiffness of the different epoxy resins was analyzed. All resin systems have shown improvement in both toughness and stiffness of the materials through the incorporation of layered silicates, despite the fact that it is often found that these two properties cannot be simultaneously achieved.     

Flame‐retardant,glass‐fabric‐reinforced epoxy resin laminates fabricated through a gradient distribution mode

In general, epoxy resin (EP) glue mixed with a high content of flame retardants is used to coat glass fabrics layer by layer to prepare fire‐retardant printed circuit boards (PCBs). However, the addition of the flame retardants not only increases the cost but also greatly deteriorates the processability and mechanical properties of the PCBs. In this study, a gradient distribution mode of composite flame retardants was designed and applied in EP‐based PCB composites. Unlike the traditional uniform distribution mode, in which flame retardants are evenly distributed in every resin layer, the gradient mode concentrates a higher content of the flame retardants on the surface layer, and the concentrations are gradually reduced along the thickness. In this way, the surface resin can quickly form a condensed charring barrier to hold back fire; this effectively protects the underlying resin, which has lower contents of flame retardant. The results of this study show that PCB prepared by the gradient mode obtained satisfactory flame retardance (a UL94 V‐0 rating) with only a 3.5 wt % total amount of flame retardant; this value was much lower than that (6.3 wt %) of composites featuring a uniform distribution. Additionally, the gradient mode also maintained the mechanical properties of PCB better. The tensile, impact, and flexural strengths of the gradient distribution system were obviously higher than those of the uniform distribution one with the same content of flame retardant. On the basis of the mode, a more economic and efficient technology was developed to manufacture flame‐retardant layered PCB. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44369.     

Miscibility and mechanical properties of tetrafunctional epoxy resin/phenolphthalein poly(ether ether ketone) blends

Phenolphthalein poly(ether ether ketone) (PEK‐C) was found to be miscible with uncured tetraglycidyl 4,4′‐diaminodiphenylmethane (TGDDM), which is a type of tetrafunctional epoxy resin (ER), as shown by the existence of a single glass transition temperature (T_g) within the whole composition range. The miscibility between PEK‐C and TGDDM is considered to be due mainly to entropy contribution. Furthermore, blends of PEK‐C and TGDDM cured with 4,4′‐diaminodiphenylmethane (DDM) were studied using dynamic mechanical analysis (DMA), Fourier‐transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM). DMA studies show that the DDM‐cured TGDDM/PEK‐C blends have only one T_g. SEM observation also confirmed that the blends were homogeneous. FTIR studies showed that the curing reaction is incomplete due to the high viscosity of PEK‐C. As the PEK‐C content increased, the tensile properties of the blends decreased slightly and the fracture toughness factor also showed a slight decreasing tendency, presumably due to the reduced crosslink density of the epoxy network. SEM observation of the fracture surfaces of fracture toughness test specimens showed the brittle nature of the fracture for the pure ER and its blends with PEK‐C. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 598–607, 2001     

Synthesis,thermal and mechanical behavior of a silicon/phosphorus containing epoxy resin

A liquid silicon/phosphorus containing flame retardant (DOPO–TVS) was synthesized with 9,10‐dihydro‐9‐oxa‐10‐phosphapheanthrene‐10‐oxid (DOPO) and triethoxyvinylsilane (TVS). Meanwhile, a modified epoxy resin (IPTS–EP) was prepared by grafting isocyanate propyl triethoxysilane (IPTS) to the side chain of bisphenol A epoxy resin (EP) through radical polymerization. Finally, the flame retardant (DOPO–TVS) was incorporated into the modified epoxy resin (IPTS–EP) through sol–gel reaction between the ethyoxyl of the two intermediates to obtain the silicon/phosphorus containing epoxy resin. The molecular structures of DOPO–TVS, IPTS–EP and the final modified epoxy resin were confirmed by FTIR spectra and ¹H‐NMR, ³¹P‐NMR. Thermogravimetric analysis (TGA), differential scanning calorimetry, and limiting oxygen index were conducted to explore the thermal properties and flame retardancy of the synthesized epoxy resin. The thermal behavior and flame retardancy were improved. After heating to 600°C in a tube furnace, the char residue of the modified resin containing 10 wt % DOPO–TVS displayed more stable feature compared to that of pure EP, which was observed both by visual inspection and scanning electron microscope (SEM). Moreover, the mechanical performance testing results exhibited the modified epoxy resins possessed elevated tensile properties and fracture toughness which is supported by SEM observation of the tensile fracture section. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42788.     

Structure and toughness of polyethersulfone (PESU)‐modified anhydride‐cured tetrafunctional epoxy resin: Effect of PESU molecular mass

A tetrafunctional, anhydride hardened epoxy resin (EP) was modified with polyethersulfones (PESU) of different molecular mass (MM) without using additional solvent in 10 wt %. The morphology, thermal, and fracture mechanical properties of the EP/PESU systems were determined. PESU was present as dispersed phase in the EP matrix. The final morphology of EP/PESU depended on MM of PESU. PESU of low and medium MM formed submicron scale spherical droplets, whereas PESU of high MM was present in micron scale inclusions of complex (sea‐island) structure. With increasing MM of PESU, the fracture mechanical properties, and especially the fracture energy, were increased. This was traced to differences in the morphology (dispersion of PESU) of the EP/PESU systems triggering different failure mechanisms. The onset of thermal degradation was slightly reduced, whereas the char yield enhanced by PESU modification compared with the reference EP. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Compatibilized the thermosetting blend of epoxy and redistributed low molecular weight poly(phenylene oxide) with triallylisocyanurate

Vinyl‐containing low molecular weight PPO (R‐PPO) was prepared by redistribution reaction between commercially available PPO and maleic anhydride (MAH) and used to modify epoxy resin (EP). TAIC was furthermore used as the compatibilizer of EP/R‐PPO system in this study. The curing reaction kinetics, compatibility of the components, morphology, dielectric properties and impact toughness of EP/R‐PPO/TAIC systems were investigated. The experimental results showed that the cured EP/R‐PPO (80/20) system had two phase morphology, the R‐PPO particles of about 1 µm were evenly dispersed in continuous epoxy phase. After addition of TAIC, the EP/R‐PPO/TAIC systems were transferred to single phase. The glass transition temperature of cured EP/R‐PPO/TAIC (80/20/10) system was 150.2 °C. With the increase of TAIC content, the dielectric constant (D_k) and dissipation factor (D_f) of cured EP/R‐PPO/TAIC systems were both reduced. The dielectric constant and dissipation factor at 1MHz of cured EP/R‐PPO/TAIC (80/20/10) system was 2.72 and 0.006, respectively. Compared with those of cured EP/R‐PPO (80/20) system (D_k = 2.82 and D_f = 0.0078 at 1MHz), they decreased by 3.6% and 23.1%, respectively. With the increase of TAIC content, the impact strength of cured EP/R‐PPO (80/20) system increased and reached to a maximum value (2.41 kJ/m²) when TAIC content was 10 phr, which was improved by 23% compared with that of cured EP/R‐PPO (80/20) system (1.96 kJ/m²). © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43293.