Melt rheology and interfacial properties of binary and ternary blends of PS,EOC, and SEBS

This works systematically investigates the interfacial properties of the binary and the ternary blends based on polystyrene (PS), ethylene octene copolymer (EOC), and styrene–ethylene–butylene–styrene (SEBS) by analyzing the melt linear rheological behavior of the blends and neat components. Moreover, the relationship between rheology, phase morphology, and mechanical properties of PS/EOC ternary blends with various quantities of SEBS were studied. The surface shear modulus (β) and interfacial tension values obtained by Palierne model indicated that the EOC/SEBS blend has the best interfacial properties, while the lowest interaction was found for PS/EOC blend. Based on the Palierne model and Harkin's spreading coefficients a core–shell type morphology with EOC phase encapsulated by the SEBS shell dispersed in the PS matrix was determined for the ternary blends. Scanning electron microscopy results revealed that both fibrillar and droplet forms of dispersed phase could be developed during the blending of PS and EOC in presence of SEBS. The extent of fibrillar morphology and interfacial interactions in PS/EOC/SEBS ternary blends was dependent on the SEBS content. The improvement of the mechanical properties of PS/EOC blends in the presence of SEBS was evidenced by the tensile and impact resistance experiments. The tensile strength reinforcement was more pronounced for the ternary blends with more fibrillar dispersed phase. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48791.     

Characterization of PA6/EPDM-g-MA/HDPE ternary blends: The role of core-shell structure

In this work, the relationship between properties and morphologies of PA6/EPDM-g-MA/HDPE ternary blends was studied. Two processing methods (one- and two-step methods) were applied to prepare the PA6/EPDM-g-MA/HDPE ternary blends. The dependence of the phase morphology on interfacial interaction and processing method was discussed here. It was found that core-shell morphology (core: HDPE, shell: EPDM-g-MA in PA6 matrix) appeared in PA6/EPDM-g-MA/HDPE ternary blends, and in comparison to the blend prepared by one-step method, the core-shell morphology with thicker EPDM-g-MA shell appeared in the blend prepared by two-step method. In this case, a super toughened PA6 ternary blends with the Izod impact strength of 72.51 kJ/m² which is 4–5 times higher than PA6/EPDM-g-MA binary blend and 9–10 times higher than pure PA6 could be achieved. Moreover, the rheological results indicated that the storage modulus of ternary blends was heavily dependent on the phase morphology. The core-shell structure with thicker EPDM-g-MA shell would weaken the contribution of interfacial energy to the storage modulus of ternary blends.     

Toughening of PA6 nanocomposites by reactive acrylonitrile–butadiene–styrene core–shell rubber particles

The effect of addition of organoclay and the reactive ABS‐g‐MA core‐shell particles on the mechanical properties and morphology of blends of polyamide (PA6) were reported. The reactive rubber particles with core‐shell structure were selected as modifier instead of conventional reactive bulk rubber. The microstructure of the ternary nanocomposites was characterized by X‐ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). Impact strength and stress–strain behavior of blends were measured as a function of organoclay content and core/shell ratio of ABS‐g‐MA. The organoclay plates affected the interfacial adhesion between polyamide and the core‐shell particles because of a shielding effect of organclay on the interacting of amine end groups of PA6 with the MA groups of ABS‐g‐MA. The poor dispersion behavior of ternary nanocomposites was observed when the core/shell ratio is 80/20, and with an increase of organoclay content, the core/shell dispersed phase size increased. Blends based on the maleated elastomer with the core/shell ratio 60/40 gave a more beneficial balance of toughness versus stiffness. POLYM. COMPOS., 35:864–871, 2014. © 2013 Society of Plastics Engineers     

A probe into the status quo of interfacial adhesion in the compatibilized ternary blends with core/shell droplets: Selective versus dictated compatibilization

A simple approach was applied to probe into the situation of interfacial adhesion in the compatibilized ternary polymer blends with core/shell morphology. The performance of compatibilization was discussed in terms of thermal, rheological, and mechanical properties analyses for blends prepared through different mixing strategies for which maleic anhydride‐grafted high‐density polyethylene (HDPE‐g‐MAH) could be localized at the interface of HDPE/poly(ethylene‐co‐vinyl alcohol) copolymer (EVOH) or HDPE/polyamide 6 (PA‐6) in their ternary blends. Two mixing strategies, one simultaneously (one‐step or selective) and two sequentially (two‐step or dictated), were performed, compared, and discussed. It was found that mixing policy (dictated or selective) significantly changes the interfacial adhesion, as signaled by variations in rheological and thermal properties. In the case of mechanical properties, facilitation of stress transfer across the matrix/shell/core interfaces was detected by calculation of semi‐experimental models' coefficients. It was found that one‐step mixing or selective localization of HDPE‐g‐MAH helps in accumulation of more compatibilizer molecules at the interface HDPE/EVOH or EVOH/PA‐6. By contrast, addition of compatibilizer to minor phase (masterbatch of EVOH and PA‐6) or to HDPE matrix alone in case of two‐step blending causes imperfect stress transfer. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45503.     

Novel ternary blends of natural rubber/linear low-density polyethylene/thermoplastic starch: influence of epoxide level of epoxidized natural rubber on blend properties

Novel degradable materials based on ternary blends of natural rubber (NR)/linear low-density polyethylene (LLDPE)/thermoplastic starch (TPS) were prepared via simple blending technique using three different types of natural rubber (i.e., unmodified natural rubber (RSS#3) and ENR with 25 and 50 mol% epoxide). The evolution of co-continuous phase morphology was first clarified for 50/50: NR/LLDPE blend. Then, 10 wt% of TPS was added to form 50/40/10: NR/LLDPE/TPS ternary blend, where TPS was the particulate dispersed phase in the NR/LLDPE matrix. The smallest TPS particles were observed in the ENR-50/LLDPE blend. This might be attributed to the chemical interactions of polar functional groups in ENR and TPS that enhanced their interfacial adhesion. We found that ternary blend of ENR-50/LLDPE/TPS exhibited higher 100 % modulus, tensile strength, hardness, storage modulus, complex viscosity and thermal properties compared with those of ENR-25/LLDPE/TPS and RSS#3/LLDPE/TPS ternary blends. Furthermore, lower melting temperature (T _m) and heat of crystallization of LLDPE (?H) were observed in ternary blend of ENR-50/LLDPE/TPS compared to the other ternary blends. Also, neat TPS exhibited the fastest biodegradation by weight loss during burial in soil for 2 or 6 months, while the ternary blends of NR/LLDPE/TPS exhibited higher weight loss compared to the neat NR and LLDPE. The lower weight loss of the ternary blends with ENR was likely due to the stronger chemical interfacial interactions. This proved that the blend with ENR had lower biodegradability than the blend with unmodified NR.     

Evolution of shell formation process in PP/PMMA/PS ternary blends: correlation between the melt rheology and phase morphology

Correlation between the melt rheology and phase morphology of PP/PMMA/PS ternary blends during the shell formation process were studied in detail. In this PP-matrix ternary system, theoretical predictions in agreement with the direct SEM observations demonstrated the core-shell morphology with PMMA and PS phases as core and shell phases, respectively. Morphological observations revealed that the complete shell formation takes place at about 12 and 9 wt% of PS minor phase in ternary blends composed of low and high viscosity PMMAs, respectively. In terms of rheological properties, this was corresponding to the maximum value on the storage modulus versus PS content (shell thickness) curves. Encapsulation of high viscosity PMMA core particles at lower PS contents was related to the bigger particles and low interfacial area in this system compared to the system with low viscosity PMMA core particles. At high PS contents, single and multi-core structures were observed for composite droplets of ternary blends containing low and high viscosity PMMAs, respectively. The single core morphology of low viscosity PMMA particles was related to the coalescence of core particles after the coalescence of the corresponding shells, while high viscosity PMMA cores are less likely to coalescence, leading to creation of multi-core morphology in latter system.     

Interface evaluation in the ternary blends of HDPE/PA-6/EVOH

In this work, a quantitative evaluation on interface situation in HDPE/PA-6/EVOH ternary blends is presented. For this purpose, binary and ternary blends based on HDPE as continuous phase and PA-6 and EVOH as minor components with different weight ratios were prepared. The morphology of the blends was studied by SEM and their mechanical properties were measured. Then, through a theoretical/experimental approach, the tensile characteristics of HDPE/PA-6/EVOH ternary blends are discussed. The interface situation in the prepared blends is probed in such a manner that phenomenological models are successfully extended to the case of ternary blends and their parameters are obtained using available predictive schemes. In addition, the stress–strain curves of all prepared binary and ternary blends comprising different PA-6 to EVOH weight ratios in the minority phase are taken into account to study the yielding and toughening phenomena followed by quantitative evaluation of interfacial adhesion. The results provided support for the fact that the yielding behavior of prepared ternary blends is dependent on the minor component fraction possibly due to the formation of voids at the interface of polymers.     

Synergetic toughness and morphology of poly(propylene)/nylon 11/maleated ethylene‐propylene diene copolymer blends

Polypropylene (PP)/nylon 11/maleated ethylene‐propylene‐diene rubber (EPDM‐g‐MAH) ternary polymer blends were prepared via melt blending in a corotating twin‐screw extruder. The effect of nylon 11 and EPDM‐g‐MAH on the phase morphology and mechanical properties was investigated. Scanning electron microscopy observation revealed that there was apparent phase separation for PP/EPDM‐g‐MAH binary blends at the level of 10 wt % maleated elastomer. For the PP/nylon 11/EPDM‐g‐MAH ternary blends, the dispersed phase morphology of the maleated elastomer was hardly affected by the addition of nylon 11, whereas the reduced dispersed phase domains of nylon 11 were observed with the increasing maleated elastomer loading. Furthermore, a core‐shell structure, in which nylon 11 as a rigid core was surrounded by a soft EPDM‐g‐MAH shell, was formed in the case of 10 wt % nylon 11 and higher EPDM‐g‐MAH concentration. In general, the results of mechanical property measurement showed that the ternary blends exhibited inferior tensile strength in comparison with the PP matrix, but superior toughness. Especially low‐temperature impact strength was obtained. The toughening mechanism was discussed with reference to the phase morphology. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Morphology prediction and the effect of core‐shell structure on the rheological behavior of PP/EPDM/HDPE ternary blends

In this work, the morphologies of polypropylene (PP)/ethylene‐propylene‐diene (EPDM) rubber/high density polyethylene (HDPE) 70/20/10 blends were studied and compared with the predictions of the spreading coefficient and minimum free energy models. The interfacial tension of PP/HDPE, PP/EPDM, and HDPE/EPDM blends were obtained by fitting the experimental dynamic storage modulus data to Palierne's theory. The prediction results showed core‐shell morphology (core of HDPE and shell of EPDM) in PP matrix. The PP/EPDM/HDPE blends were respectively prepared by direct extrusion and lateral injection method. Core‐shell morphology (core of HDPE and shell of EPDM) could be obtained with direct extrusion corresponding to the predicted morphology. The morphology of PP/EPDM/HDPE blends could be effectively controlled by lateral injection method. For PP/EPDM/HDPE blend prepared by lateral injection method, HDPE and EPDM phase were dispersed independently in PP matrix. It was found that the different morphology of PP/EPDM/HDPE blends prepared by two methods showed different rheological behavior. When the core‐shell morphology (core of HDPE and shell of EPDM) appeared, the EPDM shell could confine the deformation of HDPE core significantly, so the interfacial energy contribution of dispersed phase on the storage modulus of blends would be weaken in the low frequency region. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers     

Influence of composition and phase morphology on rheological properties of polypropylene/poly(ethylene‐co‐octene) blends

In this article, the phase morphology and rheological properties of polypropylene (PP)/poly(ethylene‐co‐octene) (POE) blends with a droplet‐matrix microstructure were studied by scanning electron microscopy and rheological experiments. The data were analyzed to yield the variations of rheological behavior with blend composition and insight into the microstructure of PP/POE blends. The Palierne's emulsion type model was used to extract information on rheological properties, and the interfacial tensions between the PP and POE were determined by fitting the experimental data with this model. The results indicated that the interfacial tensions were shown to depend on blend composition and temperature. Rheological properties of PP/POE blends were investigated in a systemic way with varying shear histories. The results showed that shear history had an important effect on the rheological properties of the blends due to the dispersed phase (POE) domains refined with increasing preshear rate and preshear time. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers     

Mechanical properties and morphology of crosslinked PP/PE blends and PP/PE/propylene–ethylene copolymer blends

Blending is an effective method for improving polymer properties. However, the problem of phase separation often occurs due to incompatibility of homopolymers, which deteriorates the physical properties of polyblends. In this study, isotactic polypropylene was blended with low-density polyethylene. Crosslinking agent and copolymers of propylene and ethylene (either random copolymer or block copolymer) were added to improve the interfacial adhesion of PP/LDPE blends. The tensile strength, heat deflection temperature, and impact strength of these modified PP/PE blends were investigated. The microstructures of polyblends have been studied to interpret the mechanical behavior through dynamic viscoelasticity, wide-angle X-ray diffraction, differential scanning calorimetry, picnometry, and scanning electron microscopy. The properties of crosslinked PP/PE blends were determined by the content of crosslinking agent and processing method. For the material blended by roll, a 2% concentration of peroxide corresponded to a maximum tensile strength and minimum impact strength. However, the mechanical strength of those products blended by extrusion monotonously decreased with increasing peroxide content because of serious degradation. The interfacial adhesion of PP/PE blends could be enhanced by adding random or block copolymer of propylene and ethylene, and the impact strength as well as ductility were greatly improved. Experimental data showed that the impact strength of PP/LDPE/random copolymer ternary blend could reach as high as 33.3 kg · cm/cm; however, its rigidity and tensile strength were inferior to those of PP/LDPE/block copolymer blend.     

Microstructural characteristics of glass bead‐ and wollastonite‐filled isotactic‐polypropylene composites modified with thermoplastic elastomers

Microstructural characteristics of isotactic‐polypropylene/glass bead (iPP/GB) and iPP/wollastonite (iPP/W) composites modified with thermoplastic elastomers, poly(styrene‐b‐ethylene‐co‐butylene‐b‐styrene) copolymer (SEBS) and corresponding block copolymer grafted with maleic anhydride (SEBS‐g‐MA), were investigated. Scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and dynamic mechanical analyses (DMA) showed that the iPP/SEBS and iPP/SEBS‐g‐MA blends were partially compatible two‐phase systems. Well‐dispersed spherical GB and acicular W particles without evidence of interfacial adhesion were observed in the iPP/GB and iPP/W binary composites respectively. Contrary to the blends, melt flow rates of the iPP/GB and PP/W composites decreased more with SEBS‐g‐MA than with SEBS because of enhanced interfacial adhesion with SEBS‐g‐MA elastomer. The SEM analyses showed that the ternary composites containing SEBS exhibited separate dispersion of the rigid filler and elastomer particles (i.e., separate microstructure). However, SEBS‐g‐MA elastomer not only encapsulated the spherical GB and acicular W particles completely with strong interfacial adhesion (i.e., core‐shell microstructure) but also dispersed separately throughout iPP matrix. In accordance with the SEM observations, the DSC and DMA revealed quantitatively that the rigid filler and SEBS particles in iPP matrix acted individually, whereas the rigid filler particles in the ternary composites containing SEBS‐g‐MA acted like elastomer particles because of the thick elastomer interlayer around the filler particles. The Fourier transform infrared analyses revealed an esterification reaction inducing the strong interfacial adhesion between the SEBS‐g‐MA phase and the filler particles. POLYM. COMPOS., 31:1265–1284, 2010. © 2009 Society of Plastics Engineers     

Effect of EPDM‐g‐MAH on the morphology and properties of PA6/EPDM/HDPE ternary blends

The formation of core‐shell morphology within the dispersed phase was studied for composite droplet polymer‐blend systems comprising a polyamide‐6 matrix, ethylene‐propylene‐diene terpolymer (EPDM) shell and high density polyethylene (HDPE) core. In this article, the effect of EPDM with different molecular weights on the morphology and properties of the blends were studied. To improve the compatibility of the ternary blends, EPDM was modified by grafting with maleic anhydride (EPDM‐g‐MAH). It was found that core‐shell morphology with EPDM‐g‐MAH as shell and HDPE as core and separated dispersion morphology of EPDM‐g‐MAH and HDPE phase were obtained separately in PA6 matrix with different molecular weights of EPDM‐g‐MAH in the blends. DSC measurement indicated that there may be some co‐crystals in the blends due to the formation of core‐shell structure. Mechanical tests showed that PA6/EPDM‐g‐MAH/HDPE ternary blends with the core‐shell morphology exhibited a remarkable rise in the elongation at break. With more perfect core‐shell composite droplets and co‐crystals, the impact strength of the ternary blends could be greatly increased to 51.38 kJ m^?2, almost 10 times higher than that of pure PA6 (5.50 kJ m^?2). POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers     

Mechanical properties and failure mode of thermoplastic elastomers from natural rubber/poly(methyl methacrylate)/natural rubber-g-poly(methyl methacrylate) blends

The mechanical properties and fracture behavior of natural rubber/poly-(methyl methacrylate) blends were investigated as a function of composition, graft copolymer concentration, and mixing conditions. The mechanical properties and failure behavior vary with the blend ratio, graft copolymer concentration, and mixing conditions. Various two-phase models were used to fit the experimental mechanical properties. Mechanical properties such as stress–strain behavior, tensile strength, tensile modulus, tear strength, and Izod impact strength were evaluated as a function of compatibilizer concentration. The domain size of the dispersed phase decreases with graft copolymer concentration followed by a leveling off at higher concentration. The mechanical properties attain a maximum value at the leveling point, which is an indication of interfacial saturation and the attainment of maximum interfacial adhesion between the homopolymers. Tensile and tear fracture surfaces were examined by scanning electron microscopy. The detachment of the dispersed domains from the matrix is an indication of no adhesion between the two phases in the case of uncompatibilized blends. Microfibrils between the matrix and the dispersed phase indicate a sign of interfacial adhesion between the phases in the case of compatibilized blends. © 1997 John Wiley & Sons, Inc. J Appl Polm Sci 65:1245–1255, 1997     

PET/EVA/PP ternary blends: An investigation of extended morphological properties

In this study, the effects of different parameters on the morphological properties of ternary blends were investigated. Therefore two systems (PET/H‐EVA/PP and PET/L ‐EVA/PP, H‐EVA and L ‐EVA are high and low viscosity, respectively) were prepared by melt mixing process. In all of the blends, poly (ethylene terephthalate) (PET) as the major phase‐ with poly propylene (PP) and two grades of poly (ethyl‐stat‐vinylacetate) (EVA) with different viscosities and subsequently different interfacial interactions was blended. Theoretical models predicted positive spreading coefficient for two grades of EVA and lower free energy for the samples consisting of EVA and PP as the shell and the core phases respectively. With changing core shell ratio, droplet size of samples containing L ‐EVA and H‐EVA increased and decreased, respectively. Subinclusion of shell into the core was observed in some blended samples. In systems containing H‐EVA, by thickening the shell phase; multi core morphology was observed which would be related to the coalescence phenomenon inter the droplets. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Ultraporous poly(l-lactide) scaffolds prepared with quaternary immiscible polymer blends modified by copolymer brushes at the interface

The activity of polystyrene-block-poly(l-lactide) (PS-b-PLLA) and polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA) diblock copolymer brushes located at a PS/PLLA interface were employed as a route to control the final microstructure of 95% void volume, ultraporous PLLA scaffolds. The latter were initially prepared from melt-processed quaternary blends of ethylene propylene diene rubber/poly(?-caprolactone)/polystyrene/poly(l-lactide) (EPDM/PCL/PS/PLLA) 45/45/5/5%vol. modified with the diblock copolymers. The blends display a layer comprised of the PS and PLLA phases located at the interface of the co-continuous EPDM and PCL phases. When the PS-b-PLLA copolymer is added, sub-micrometric PLLA droplets are encapsulated within the PS continuous layer phase. In comparison, both the PS and PLLA phases compete for the encapsulation process when the PS-b-PMMA is used, indicating that the microstructure of the PLLA phase can be fine-tuned with an adequate choice of interfacial modifier. These effects were investigated by analyzing the microstructure of ternary high-density polyethylene (HDPE)/PS/PMMA 80/10/10%vol. blends displaying PS/PMMA shell/core composite droplets in a HDPE matrix. An inversion of the shell/core structure is observed when the PS-b-PLLA copolymer is used to compatibilize the PS/PMMA interface, whereas no such restructuring occurs with the PS-b-PMMA. These effects are explained by the activity and swelling powers of the copolymer brushes. For the EPDM/PCL/PS/PLLA quaternary systems modified with the PS-b-PMMA, the PLLA homopolymer phase significantly penetrates and swells the PMMA blocks due to their mutual high affinity, as compared to the classical like-prefers-like compatibilization approach. The swelling of the blocks will tend to bend the interface toward the PS phase in order to minimize the lateral compression of the PMMA blocks. A similar effect explains the reversal of the PS/PMMA shell/core structure in the HDPE/PS/PMMA ternary system. This level of control ultimately leads to quite significant differences in microstructures and surface textures for the PLLA scaffolds.     

Effect of added ionomer on morphology and properties of PP/organoclay nanocomposites

Ethylene-methacrylic acid ionomer (Surlyn) with concentration up to 20 wt% based on total weight of polymer resin was added into polypropylene (PP)/organoclay hybrids. The microstructure, rheological properties, crystallization properties and mechanical properties of the obtained nanocomposites have been investigated. The addition of ionomer markedly enlarged interlayer spacing of the platelets and led to an improved degree of exfoliation. Moreover, clay silicates were found to selectively disperse either inside the ionomer phase or at the phase boundary. Compared to the binary immiscible blends, an improved interfacial adhesion was achieved for PP/Surlyn/OMMT hybrids. Unlike PP/Surlyn binary blends, the viscoelastic properties of the hybrids significantly increased with increasing Surlyn concentration, which could be attributed to the improved clay dispersion and the contribution of silicate layers at the interface between PP and Surlyn. A synergistic role between Surlyn and clay was also found to suppress the crystallization of PP matrix. In addition, PP/Surlyn/OMMT hybrids exhibited superior tensile strain compared to the corresponding PP/PP-g-MA/OMMT. Both tensile strength and elongation at break showed maximum at Surlyn concentration of 5 wt%. By comparing the experimental tensile yield strength with model prediction, it was suggested that the clay platelets localized at the interface could play a role of interfacial activation to some extent.     

AS／MBS／EVA三元共混体系力学性能及微观形态

研究了AS/MBS/EVA三元共混体系的力学性能及微观形态。采用EVA作为相容剂改善核壳型粒子MBS在AS基体中的分散 ,达到良好效果 ,在保持AS良好弯曲性能的同时 ,提高了基体的缺口冲击强度。     

Preparation of PBT/POE-g-GMA/PP ternary blends with good rigidity–toughness balance by core–shell particles

Compared with poly(butylene terephthalate)/glycidyl methacrylate grafted poly(ethylene–octene) (PBT/POE-g-GMA) binary blends, supertough PBT-based ternary blends with little rigidity loss were successfully obtained by adding rigid polypropylene (PP) into PBT/POE-g-GMA blends to construct core–shell particles during melt blending. The effects of PP content and type on the phase morphology and mechanical properties of the blends were systematically investigated. Theoretical predictions and scanning electron microscopy observation showed that a core–shell structure was formed in PBT matrix with PP as the core and POE-g-GMA as the shell. The mechanical property tests showed that POE-g-GMA and PP had significant synergistic toughening effect. When PP with high melt flow index (H-PP) was used, PBT/POE-g-GMA/H-PP (70/15/15) blends possessed the highest Izod notched impact strength, which was 1.9-fold compared with PBT/POE-g-GMA (70/30) binary blends, while the tensile performance loss was little. The essential work of fracture tests was performed to evaluate the fracture resistance of different samples. The results demonstrated that PBT/POE-g-GMA/PP ternary blends possessed much better resistance to crack propagation than PBT/POE-g-GMA binary blends. The decrease of interparticle distance and the fibrillation of core–shell particles activated intense matrix shear yielding, which was the reason for the high crack resistance of ternary blends. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48872.     

Simultaneously improved toughness and dielectric properties of epoxy/core‐shell particle blends

Epoxy/core‐shell particle blends were prepared using a diglycidylether of bisphenol A epoxy and acrylics‐type core‐shell particles. The impact strength of the blends was tested, and the result showed that the epoxy was greatly toughened with optimum core‐shell particle content. Meanwhile, the dielectric properties of both epoxy and its blends were investigated using a broadband dielectric analyzer. It was found that the dielectric constant of the epoxy blends with lower core‐shell particle content were less than that of the epoxy in the investigated frequency range, while the dielectric loss was less than that of the neat epoxy over a low frequency range, even for the epoxy blends with the optimum core‐shell particle content. The dielectric breakdown strength of the epoxy blends at room and cryogenic temperature were also investigated. To identify the primary relationship of the above properties and structure of the epoxy blends, the microstructure of the core‐shell particle and the morphology of the samples were observed by transmission electron microscopy and scanning electron microscopy. It was considered that these epoxy/core‐shell particle blends with improved toughness and desirable dielectric properties could have a potential application in the insulation of electronic packaging system. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008