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Achieving high thermal conductivity in composites with low filler content is a major challenge in current research. In this paper, polypropylene (PP) and polyamide 6 (PA6) were used as polymer matrix, and the hybrid thermal conductive filler, formed by hexagonal boron nitride (h‐BN) and aminated carbon nanotubes (NH2‐CNTs), was integrated into matrix for the fabrication of thermal conductive composites (PP/PA6/h‐BN and PP/PA6/h‐BN@CNTs) via two‐step melt blending technology. The thermal conductive fillers were selectively distributed in a phase of the polymer matrix with a co‐continuous structure, forming a thermal conductive path with a three‐dimensional network structure. The results show that when the content of h‐BN reaches 25 wt%, the thermal conductivity of the PP/PA6/h‐BN and PP/PA6/h‐BN@CNTs composites was 199% and 300% higher than that of PP/PA6, respectively. Through testing the volume resistivity of the composites, it was confirmed that PP/PA6/h‐BN@CNTs composites maintain good electrical insulation. Both composites demonstrated remarkable thermal conductivity and outstanding electrical insulation. This research provides a facile way to prepare highly thermal conductivity polymer composites with excellent processing performances and electrical insulation. Highlights: h‐BN@CNTs hybrid fillers with sandwich structure were prepared.A two‐step blending method was used to control the selective distribution of hybrid fillers in a phase of the polymer matrix with a co‐continuous structure.The hybrid filler formed a thermal conductive path with a three‐dimensional network structure in the collective.PP/PA6/h‐BN@CNTs composites demonstrated remarkable thermal conductivity, outstanding electrical insulation and favorable processing performances. [ABSTRACT FROM AUTHOR]

Towards the goal of developing renewable, biocompatible and intelligent polymer materials, natural Eucommia ulmoides gum (EUG) was modified via epoxidation and then the epoxidized EUG (EEUG) was compounded with another sustainable and biobased polymer, polylactic acid (PLA), to develop shape memory thermoplastic vulcanizates (TPVs) through reactive blending. The prepared PLA/EEUG TPVs displayed not only enhanced toughness but also greatly improved shape recovery ability, which was generated from the co‐continuous phase structure and excellent interfacial adhesion induced by in situ compatibilization during reactive blending. It is shown that dicumyl peroxide content exerted little influence on the toughness of the TPVs. However, heat‐triggered shape memory effects of the TPVs were significantly affected by the dicumyl peroxide content with a decrease in deformation ratio (Δε) from 163.51% to 128.36% and an increase in shape recovery ratio (Rr) from 73.32% to 91.93%. The findings of the present study offer an idea for the industrialization of biocompatible and smart materials for biomedical applications. © 2024 Society of Industrial Chemistry. [ABSTRACT FROM AUTHOR]

Blending is an effective way to improve properties of rubbers and develop new materials, so more than 75 % of the rubber consumption in the world is rubber blend. However, blending of thermoplastic elastomers has not yet been emphasized, and few successful examples have been reported. The main challenge for blend systems is compatibility of two components. Herein, a series of (polydimethylsiloxane-based PU)-g-(poly (propylene glycol)-based PU) ((PDMS-PU)-g-(PPG-PU)) graft copolymers with different graft chain lengths and hard segment contents (HSC) were synthesized and utilized as compatibilizers of PDMS-PU/PPG-PU blends. The influence of the structure of compatibilizers on the morphology of blends was investigated, and the compatibilization mechanism was proposed. With the solubilization, the phase structure of blends transforms from "droplet-in-matrix" morphologies to co-continuous ones, and the average size of PPG-PU dispersed phase decreases from 3.5 ± 0.45 μm to 230 ± 60 nm. This is the first time that thermoplastic PDMS-PU/PPG-PU blends with co-continuous structures have been successfully prepared. The properties of blends exhibit synergistic effects. For example, they show high tensile strength of PPG-PU in mechanical properties and unique properties of PDMS in dynamic mechanical properties, weather resistance, water resistance and biocompatibility. In addition, strain sensors were fabricated by introducing carbon nanotubes (CNTs) into the blends, which demonstrated remarkable sensing capability for diverse human body motions. [Display omitted] • By adjusting the structural parameters of the compatibilizers, PDMS-PU/PPG-PU blends are transformed to a co-continuous morphology structure, with the average size of dispersed phase reaching a hundred-nanometer scale. • The tensile strength of blends with co-continuous structure increases by 1.3 times in comparison to that of blends without compatibilizers. • The blends with co-continuous structure exhibit high tensile strength of PPG-PU in mechanical properties and unique properties of PDMS in thermal resistance, weather resistance, water resistance and biocompatibility. • The blends are expected to be applied in flexible sensors and wearable devices. [ABSTRACT FROM AUTHOR]

For the first time, the double electrical percolation threshold was obtained in polylactide (PLA)/polycaprolactone (PCL)/graphene nanoplatelet (GNP) composite systems, prepared by compression moulding and fused filament fabrication (FFF). Using scanning electron microscopy (SEM) and atomic force microscopy (AFM), the localisation of the GNP, as well as the morphology of PLA and PCL phases, were evaluated and correlated with the electrical conductivity results estimated by the four-point probe method electrical measurements. The solvent extraction method was used to confirm and quantify the co-continuity in these samples. At 10 wt.% of the GNP, compression-moulded samples possessed a wide co-continuity range, varying from PLA55/PCL45 to PLA70/PCL30. The best electrical conductivity results were found for compression-moulded and 3D-printed PLA65/PCL35/GNP that have the fully co-continuous structure, based on the experimental and theoretical findings. This composite owns the highest storage modulus and complex viscosity at low angular frequency range, according to the melt shear rheology. Moreover, it exhibited the highest char formation and polymers degrees of crystallinity after the thermal investigation by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), respectively. The effect of the GNP content, compression moulding time, and multiple twin-screw extrusion blending steps on the co-continuity were also evaluated. The results showed that increasing the GNP content decreased the continuity of the polymer phases. Therefore, this work concluded that polymer processing methods impact the electrical percolation threshold and that the 3D printing of polymer composites entails higher electrical resistance as compared to compression moulding. [ABSTRACT FROM AUTHOR]

In order to prepare high ionic conductivity and robust mechanical properties of alkaline solid polyelectrolyte (ASPE) for applications in flexible wearable devices, a co-continuous structure membrane was designed using in-situ polymerization to introduce cross-linked polyacrylic acid (N-PAA) into the cellulose network constructed by regenerated degreasing cotton (RDC). The resultant ASPE membrane showed high ionic conductivity (430 mS·cm−1 at 25 °C), strong mechanical properties, and excellent alkaline stabilities, proving the viability of cellulose for use in energy storage systems. Surprisingly, the sandwich-shaped zinc-air battery assembled using RDC/N-PAA/KOH membranes as electrolytes exhibits superior values of cycling stability, discharge time, specific capacity (731.5 mAh·g−1), peak power density (40.25 mW·cm−2), and mechanical flexibility. Even under bending conditions, the zinc-air batteries still possess stable energy supply performance, suggesting this novel solid polyelectrolyte has promising application for wearable technology. [Display omitted] • Alkaline solid polyelectrolyte with co-continuous structures is prepared. • High ionic conductivity and excellent mechanical properties are achieved. • Zinc-air batteries in the bent state exhibit reliable performance. • Supercritical drying technology and in-situ polymerization methods are employed. [ABSTRACT FROM AUTHOR]

Nanoparticle-doped polymeric composites usually suffer from poor mechanical toughness and strength, due to the hard formation of co-continuous submicron structure between matrix and nanoparticles. Here, a universal strategy to construct a co-continuous submicron structure in nanoparticle-doped polymeric composites was proposed for significant mechanical enhancement via integrating Pickering emulsion and copolymerization. The surface-grafted cellulose nanocrystals (CNCs) acted as the solid surfactant of Pickering emulsion forming an isolated percolation network, combined with the copolymerization of surface-grafted CNCs and polymer matrix, generating stronger interaction in composites. The poly(styrene-co-acrylate)/methylacryloyl-grafted CNC (PSA/mCNC) composites were obtained from one-pot Pickering emulsion polymerization. The tensile strength and the elongation at break of PSA/mCNC composites increased by 107% and 681%, respectively, when mCNCs were 0.5 wt%. The mechanical performance of PSA/mCNC composites exceeded the best PSA/CNC composites, whose tensile strength and the elongation at break only increased by 51% and 650%, respectively. The PSA/mCNC composites showed higher mechanical performance and simpler post-process, compared with similar commercial products. This strategy is universal for mechanical enforcement of other polymeric composites. [ABSTRACT FROM AUTHOR]

Magnesium composites reinforced by N-deficient Ti2AlN MAX phase were first fabricated by non-pressure infiltration of Mg into three-dimensional (3D) co-continuous porous Ti2AlNx (x = 0.9, 1.0) preforms. The relationship between their mechanical properties and microstructure is discussed with the assessment of 2D and 3D characterization. X-ray diffraction (XRD) and scanning electron microscopy detected no impurities. The 3D reconstruction shows that the uniformly distributed pores in Ti2AlNx preforms are interconnected, which act as infiltration tunnels for the melt Mg. The compressive yield strength and microhardness of Ti2AlN0.9/Mg are 353 MPa and 1.12 GPa, respectively, which are 8.55% and 6.67% lower than those of Ti2AlN/Mg, respectively. The typical delamination and kink band occurred in Ti2AlNx under compressive and Vickers hardness (VH) tests. Owing to the continuous skeleton structure and strong interfacial bonding strength, the crack initiated in Ti2AlNx was blocked by the plastic Mg matrix. This suggests the possibility of regulating the mechanical performance of Ti2AlN/Mg composites by controlling the N vacancy and the hierarchical structure of Ti2AlN skeleton. [ABSTRACT FROM AUTHOR]

Ti 3 AlC 2 /2024Al composites with a co-continuous structure were successfully fabricated from 2024Al powders and Ti 3 AlC 2 porous preforms (with porosity of 48%, 41% and 35%, respectively) by pressureless infiltration at 930 °C. Long-rod like Al 3 Ti was in situ formed due to reaction of Ti atoms de-intercalated from Ti 3 AlC 2 and liquid 2024Al, which interpenetrated with Ti 3 AlC 2 to form a new continuous framework. The mechanical properties in relationship with the initially different volume fractions of Ti 3 AlC 2 and 2024Al at room temperature and high temperature were investigated. At room temperature, 59 vol%Ti 3 AlC 2 /2024Al has the best comprehensive mechanical properties, with the flexural strength of 510 MPa, compressive strength of 729 MPa, and compressive strain of 5.49%. Due to the co-continuous structure and the excellent high temperature of Al 3 Ti, all samples exhibit well mechanical properties at 300 °C. Among them, 52 vol%Ti 3 AlC 2 /2024Al has the best performance with the ultimate compressive strength of 532 MPa, which is only 18.7% lower than room temperature. And even at 400 °C,it still has an objective compression strength of 394 MPa due to the highest content of Al 3 Ti. In addition, after quenching from 400 °C to room temperature, the residual flexural strength of 52 vol%Ti 3 AlC 2 /2024Al can be reached to 450 MPa with the mere reduction rate of 7.4%. And no cracks are observed at the boundary of each phase, which means the good thermal shock resistance of the composites. [ABSTRACT FROM AUTHOR]

Structural engineering is an appealing means to modulate osteogenesis without the intervention of exogenous cells or therapeutic agents. In this work, a novel 3D scaffold with anisotropic micropores and nanotopographical patterns is developed. Scaffolds with oriented pores are fabricated via the selective extraction of water-soluble polyethylene oxide from its poly(ε-caprolactone) co-continuous mixture and uniaxial stretching. The plate apatite-like lamellae are subsequently hatched on the pore walls through surface-induced epitaxial crystallization. Such a unique geometric architecture yields a synergistic effect on the osteogenic capability. The prepared scaffold leads to a 19.2% and 128.0% increase in the alkaline phosphatase activity of rat bone mesenchymal stem cells compared to that of the scaffolds with only oriented pores and only nanotopographical patterns, respectively. It also induces the greatest upregulation of osteogenic-related gene expression in vitro. The cranial defect repair results demonstrate that the prepared scaffold effectively promotes new bone regeneration, as indicated by a 350% increase in collagen I expression in vivo compared to the isotropic porous scaffold without surface nanotopology after implantation for 14 weeks. Overall, this work provides geometric motifs for the transduction of biophysical cues in 3D porous scaffolds, which is a promising option for tissue engineering applications., (© 2024 Wiley‐VCH GmbH.)

For the first time, the double electrical percolation threshold was obtained in polylactide (PLA)/polycaprolactone (PCL)/graphene nanoplatelet (GNP) composite systems, prepared by compression moulding and fused filament fabrication (FFF). Using scanning electron microscopy (SEM) and atomic force microscopy (AFM), the localisation of the GNP, as well as the morphology of PLA and PCL phases, were evaluated and correlated with the electrical conductivity results estimated by the four-point probe method electrical measurements. The solvent extraction method was used to confirm and quantify the co-continuity in these samples. At 10 wt.% of the GNP, compression-moulded samples possessed a wide co-continuity range, varying from PLA55/PCL45 to PLA70/PCL30. The best electrical conductivity results were found for compression-moulded and 3D-printed PLA65/PCL35/GNP that have the fully co-continuous structure, based on the experimental and theoretical findings. This composite owns the highest storage modulus and complex viscosity at low angular frequency range, according to the melt shear rheology. Moreover, it exhibited the highest char formation and polymers degrees of crystallinity after the thermal investigation by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), respectively. The effect of the GNP content, compression moulding time, and multiple twin-screw extrusion blending steps on the co-continuity were also evaluated. The results showed that increasing the GNP content decreased the continuity of the polymer phases. Therefore, this work concluded that polymer processing methods impact the electrical percolation threshold and that the 3D printing of polymer composites entails higher electrical resistance as compared to compression moulding.

Mimicking the complex structure of natural bone remains a challenge for bone tissue scaffolds. In this study, a novel processing strategy was developed to prepare the bone-like scaffolds that are featured by highly oriented and fully interconnected pores. This type of biomimetic scaffolds was evolved from solid phase stretching of immiscible polycaprolactone (PCL)/poly(ethylene oxide) (PEO) blends with co-continuous structure and the pore morphology was inherited from selective extraction of water soluble PEO phase. The pore anisotropy was readily tuned by varying the stretching strain without loss of interconnectivity. Significant promotion in preosteoblast proliferation, alkaline phosphatase activity and osteogenic gene expression was observed in the oriented porous scaffolds compared to the isotropic porous counterpart. The oriented architecture provided a topographical cue for aligned growth of preosteoblasts, which activated the Wnt/β-catenin signaling pathway. The proposed strategy enriches the toolbox for the scaffold design and fabrication for bone tissue engineering. [ABSTRACT FROM AUTHOR]

Here, poly(lactic acid) (PLA)/poly(methyl methacrylate)-grafted natural rubber (NR-PMMA)/natural rubber (NR) ternary blends with co-continuous phase structure were prepared via peroxide-induced dynamic vulcanization. The good compatibility between NR-PMMA with PLA and NR and the interfacial grafting reaction during the preparation process ameliorated the interfacial compatibility between the phases. Therefore, the energy stored in the rubber phases could be effectively transferred to PLA, thus achieving an excellent shape-memory effect even under-repeated shape-memory cycles. Furthermore, by adding 10 wt% NR-PMMA, the TPVs exhibited improved impact strength and tensile strength up to 98.05 kJ/m2 and 45.2 MPa, respectively. [ABSTRACT FROM AUTHOR]

A novel functional compatibilization strategy for poly(lactic acid) (PLA)/poly(butylene adipate- co -butylene terephthalate) (PBAT) was developed by combining reactive maleic anhydride segments with imidazolium cations. The results revealed that the PSM-R compatibilizer with the longest alkyl chains was more efficient for compatibilization, which was ascribed to the formation of a stable co-continuous structure in the matrix. Moreover, the PLA/PBAT blends exhibited excellent antibacterial properties against both gram-positive and gram-negative bacteria. [Display omitted] • A novel functional compatibilization strategy for PLA/PBAT blend was developed. • PSM-R with longer alkyl chain compatibilized the PLA/PBAT blends more efficiently. • A stable co-continuous structure was produced in PLA/PBAT blends using PSM-R. • PLA/PBAT blends exhibited excellent antibacterial performance. Blends of poly(lactic acid) (PLA) and poly(butylene adipate- co -butylene terephthalate) (PBAT) are currently the most widely studied biodegradable blends and have great potential to replace conventional polyolefin and polyester materials. However, PLA/PBAT blends still face the challenges of poor compatibility and antibacterial performance in the practice applications. In this study, antibacterial functional PLA/PBAT blends were fabricated using an alternative copolymer (PSM-D) composed of reactive maleic anhydride segments and imidazolium cations. The results revealed that PSM-D, with long alkyl chains, improved the compatibility, antibacterial properties, and mechanical properties of the PLA/PBAT blends. Under the optimized conditions, the elongation at break of PLA/PBAT blends was increased by 750%. Detailed analysis demonstrated that these outstanding improvements could be ascribed to the formation of a stable co-continuous structure in the PLA/PBAT matrix. Furthermore, the PLA/PBAT blends exhibited excellent antibacterial properties against both gram-positive Staphylococcus aureus and gram-negative Escherichia coli , which was attributed to the presence of imidazolium cations with long alkyl chains. This study provides a new "two-in-one" platform for fabricating functional compatibilization strategies for biodegradable polymer blends and is expected to have broad implications and practical relevance for packaging and medical devices. [ABSTRACT FROM AUTHOR]

The microstructure and macroscopic properties of thermoplastic polyurethanes (TPUs) are significantly affected by their microphase separation. It is therefore of great interest to quantitatively characterize the microphase separation of TPUs and explore its connection with their mechanical properties. In this work, a method based on atomic force microscopy is proposed to visualize and quantify the microphase separation of polyether TPUs with different hard segment contents. The lateral correlation length was proposed to describe the scale of microphase separation and the microscopic Young's modulus distributions were also obtained for comparison. Results show that the macroscopic Young's modulus of the polyether TPU is consistent with the microscopic Young's modulus only when the lateral correlation length reaches a certain threshold. Besides, the studied polyether TPU exhibits the best overall mechanical properties when it reaches the maximal lateral correlation length. The proposed AFM-based method demonstrates a versatile analytical tool for quantitatively assessing the microphase separation and unveiling the relationship between the microphase separation, microscopic mechanical properties, and the macroscopic properties of TPUs. • Quantitatively control tapping force to obtain high-resolution AFM images of TPUs • Lateral correlation length is proposed to quantitatively describe the microphase separation of TPUs • Determine the microscopic Young's modulus of TPUs and compare it with the microphase separation • Establishing the relationships between microstructure and mechanical properties of TPUs through lateral correlation length [ABSTRACT FROM AUTHOR]

Brillouin and NMR spectroscopy were used to explore transitions in the structuring of liquid binary mixtures composed of water and a deep eutectic solvent (DES) known as malicine and composed of malic acid (MA) and choline chloride (ChCl). Malicine/H 2 O binary mixtures were studied for DES contents ranging from 100 to 40 wt%. Data representation of sound propagation velocities – obtained from Brillouin spectroscopy – versus DES content exhibited two well-differentiated linear regimes above and below ca. 70 DES wt% while transitioning from a "water-in-DES" system to a "DES-in-water" one along with dilution. Two linear regimes intersecting at ca. 70 DES wt% were also observed when representing the self-diffusion coefficients versus malicine contents, with MA and ChCl – and even water – exhibiting nearly identical self-diffusion coefficients for contents above 70 wt%, that diverged for contents below 70 wt%. Interestingly, further insights about this behaviour were provided by spin-lattice relaxation time of MA, also revealing the occurrence of hydrophobic hydration around non-polar moieties as in other aqueous binary mixtures of non-ionic H-bond co-solvents – e.g., DMSO:H 2 O or dioxane:water. Unlabelled Image • Two well-differentiated systems in aqueous dilutions of malicine • Water-in-DES system becomes a DES-in-water one along with dilution. • Brillouin and NMR spectroscopies point to the dilution range for transition. • Water as a secondary HBD molecule – besides ChCl – in the water-in-DES system [ABSTRACT FROM AUTHOR]

Co-continuous morphologies have attracted substantial attention recently as it possesses a significant toughening effect. However, these investigations of toughening poly (lactic acid) (PLA) with co-continuous structure have been limited to simply qualitative explanation. The "reinforced concrete"-like structure is obviously different from the classic "sea-island" structure. Therefore, considering these toughening elements of the rubber content, interfacial cohesion strength and the strength of rubber, and referring to relevant theory models of reinforced concrete, we have established an original theoretical toughening model, at least semi-quantitatively, of the binary PLA-based thermoplastic vulcanizates (TPVs) with co-continuous structure based on PLA/natural rubber (NR) TPVs. Moreover, we reveal that the calibration model is suitable for PLA/nitrile butadiene rubber (NBR) and PLA/epoxidized natural rubber (ENR) systems, with a perfectly Adj. R-Square of 0.97 and 0.94, respectively. It should be mentioned that natural properties of NBR and ENR are significantly distinguished from NR. This study opens up a viable way to quantitatively understand the toughening mechanism with co-continuous structure. Image 1 • The construction of toughening model for TPVs with co-continuous structure. • The inspiration comes from the comparison of its structure and reinforced concrete. • Interfacial cohesion and rubber strength are essential factors for impact property. • This model shows a good precision and suitability for PLA/NBR and PLA/ENR TPVs. [ABSTRACT FROM AUTHOR]

Abstract Liquid binary mixtures of deep eutectic solvents (DESs) with H 2 O are lately attracting the interest of many research works because of the improved performance that these dilutions demonstrated in number of application – e.g., catalysis, separations, or biochemistry, among others – as compared to their respective neat DES counterparts. Interestingly, molecular simulations have revealed that, despite the macroscopically homogeneous appearance of the DES/H 2 O binary mixtures, phase segregation may occur at the nanoscale. Spectroscopic studies corroborating this event in this sort of mixtures are basically limited to NMR-based ones determining diffusion coefficients and some recent Brillouin spectroscopic studies performed for a quite short list of binary DESs – i.e., those composed of one single hydrogen bond donor (HBD) and one single hydrogen bond acceptor (HBA), being urea-choline-chloride-based DES the most widely studied. Interestingly, NMR data such as chemical shifts and relaxation times have also proved quite useful for the study of liquid binary mixtures different than DES-based ones – e.g., ionic-liquid-based ones. Herein, we have obtained a full set of NMR data – chemical shifts, diffusion coefficients and relaxation times – from liquid binary mixtures of H 2 O and a ternary DESs, in this particular case one composed of two HBD – e.g., resorcinol and hexylresorcinol – and one HBA – tetraethyl ammonium bromide. Good correlation among different NMR data as well as between NMR and Brillouin data was found in the determination of the DES content at which phase segregation occurs. Graphical abstract Unlabelled Image Highlights • Deep eutectic solvents • Aqueous binary mixtures • Brillouin spectroscopy • Diffusion coefficients • Relaxation times [ABSTRACT FROM AUTHOR]

Abstract Two phase morphologies (i.e., "sea-island structure" and "co-continuous structure") were obtained in poly(methyl methacrylate) (PMMA)/acrylonitrile-styrene-acrylate copolymer (ASA) (80/20, w/w) blends and PMMA/chlorinated polyethylene (CPE) (80/20, w/w) blends, respectively. An interesting result was that the unnotched Izod impact strengths of PMMA/ASA and PMMA/CPE were approximately the same while the notched Izod impact strength of PMMA/ASA was twice that of PMMA/CPE. In order to explore the causes of this phenomenon, a series of tests were carried out. The phase morphologies were verified by selective extraction test, scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). Double-notch four-point-bending (DN-4PB) tests and the comparison of normal and notched tensile tests demonstrated that the CPE network in PMMA/CPE was notch sensitive and more easily destroyed than ASA particles in PMMA/ASA, hence a toughening mechanism was proposed. Other tests, such as rheological properties, dynamic mechanical thermal analysis (DMTA), SEM of impact-fractured surfaces, tensile and flexural properties, were also conducted. This work might have guiding significance for designing polymer blends with different phase morphologies. Highlights • Sea-island structure and co-continuous structure were fabricated in PMMA/ASA and PMMA/CPE blends, respectively. • The morphologies were verified by selective extraction test, SEM and EDS. • The correlations between impact properties and phase morphologies were investigated by DN-4PB test and tensile test. • The toughening mechanism was proposed where the CPE network was easier to be destroyed than ASA particles in PMMA blends. • This work has guiding significance for designing polymer blends with different phase morphologies. [ABSTRACT FROM AUTHOR]

In this work, hybrid conductive fillers of carbon black (CB) and carbon nanotubes (CNTs) were introduced into polylactide (PLA)/thermoplastic poly(ether)urethane (TPU) blend (70/30 by weight) to tune the phase morphology and realize rapid electrically actuated shape memory effect (SME). Particularly, the dispersion of conductive fillers, the phase morphology, the electrical conductivities and the shape memory properties of the composites containing CB or CB/CNTs were comparatively investigated. The results suggested that both CB and CNTs were selectively localized in TPU phase, and induced the morphological change from the sea-island structure to the co-continuous structure. The presence of CNTs resulted in a denser CB/CNTs network, which enhanced the continuity of TPU phase. Because the formed continuous TPU phase provided stronger recovery driving force, the PLA/TPU/CB/CNTs composites showed better shape recovery properties compared with the PLA/TPU/CB composites at the same CB content. Moreover, the CB and CNTs exerted a synergistic effect on enhancing the electrical conductivities of the composites. As a result, the prepared composites exhibited excellent electrically actuated SME and the shape recovery speed was also greatly enhanced. This work demonstrated a promising strategy to achieve rapid electrically actuated SME via the addition of hybrid nanoparticles with self-networking ability in binary PLA/TPU blends over a much larger composition range. [ABSTRACT FROM AUTHOR]

Elastomer has been proved to be a prominent toughener for polylactide (PLA), however, the remarkable increase in toughness always accompanies a sharp decrease in tensile strength. In this work, based on rubber reinforcement theory and interfacial compatibilization technique, co-continuous PLA/natural rubber (NR)/silica (SiO 2 ) thermoplastic vulcanizates (TPVs) with balanced stiffness and toughness were designed. By employing thermodynamic and kinetic factors, SiO 2 was restricted to distribute in rubber phase or at the interface due to the strong physical entanglements between NR and SiO 2 , which played a significant role in reinforcing rubber and interfacial compatibilization. As a result, impact strength of the TPVs was greatly improved without decrease in tensile strength. With 12.5 phr SiO 2 , impact strength increased to 85.1 kJ/m 2 (without fracture), which was 8 times of blank sample and 30 times than that of neat PLA, respectively. In addition, the influence of reinforced rubber, superior interfacial adhesion on fracture toughness and deformation mechanism were investigated semi-quantitatively under digital Izod impact tests. [ABSTRACT FROM AUTHOR]

Controlling the dispersed-to-continuous transition (DCT) in immiscible polymer blends is still a challenging task due to multiple parameters dependency of DCT in the mixing process. In this study, the DCT of different polymer blends was investigated through controlling the viscoelastic asymmetry of polymers. The results demonstrate that the DCT is well correlated with the deformation of the dispersed domains and the ability to raise the aspect ratio of the dispersed domains. Both the viscosity ratio and the elasticity ratio are important to determine the aspect ratio of the dispersed domains. A diagram was suggested to control the DCT concentration by viscoelastic asymmetry, i.e., viscosity ratio and elasticity ratio. It is proved that DCT concentration as low as about 10% can be achieved for Polycarbonate/Poly (lactic acid) (PC/PLA) blends at the suitable viscoelastic asymmetry. [ABSTRACT FROM AUTHOR]

Organic-inorganic hybridization is an important way to improve ablation resistance of phenolic resin coatings (PR). However, long molecular chain silicone by copolymerization is less compatible with PR and hybrid resin will form sea-island phase, which is not favorable for further improvement of ablation resistance. Therefore, how to achieve a combination of long chain and compatibility is a major challenge. In this work, the poly(dimethyl-diphenyl-imide)siloxane (PMPI) containing imide and phenyl was synthesized by anionic ring-opening polymerization and copolymerization. Then, it was hybridized with PR to obtain PMPI/PR-based double network hybrid resin coatings with nano co-continuous phase. The oxyacetylene ablation test suggests that the resin coatings with medium phenyl content has the lowest linear ablation rate (0.055 mm/s), which is 74 % lower compared to PR (0.21 mm/s). In addition, the mechanism by which PMPI enhances ablation resistance is discussed. This work provides a promising approach to develop higher performance ablative-resistant resin coatings. [Display omitted] • A novel poly(dimethyl-diphenyl-imide)siloxane containing imide rings and phenyl groups was synthesized. • Nano co -continuous structure of poly(dimethyl-diphenyl-imide)siloxane/phenolic hybrid resin was obtained. • The effect of phenyl on ceramization process of resin coatings during ablation was investigated. [ABSTRACT FROM AUTHOR]

Carbon black (CB)-filled polypropylene (PP) with surface resistivity between 106 and 109 Ω sq−1 is the ideal antistatic plastic material in the electronics and electric industry. However, a large amount of CB may have an adverse effect on the mechanical properties and processing performance of the material, thus an improved ternary system is developed. Blends of CB-filled PP and polyamide 6 (PA6) have been prepared by melt blending in order to obtain electrically conductive polymer composites with a low electrical percolation threshold based on the concept of double percolation. The morphological developments of these composites were studied by scanning electron microscopy. The results showed that CB particles were selectively dispersed in PA6 phases due to the good interaction and interfacial adhesion between CB and PA6. At the same CB loadings, the surface resistivity of PP/PA6/CB composite was smaller than that of PP/CB composite system, which indicated the better conductivity in the former composite. The increasing amount of PA6 in the composites changed the morphology from a typical sea–island morphology to a co-continuous morphology. What is more, with 8 wt% of CB and PP/PA6 phase ratio of 70/30 in which the PP and PA6 phases formed a co-continuous structure, the electrical conductivity of the composite peaked at 2.01 × 105 Ω sq−1.

Co-continuous structure with tens of nanometers was obtained in polysiloxane modified phenolic resin by using of a novel couple agent. The couple agent was synthesized through addition reaction between resorcinol and isocyanatopropyltrimethoxysilane; then, it was introduced into the mixture of silane monomers, phenol and formaldehyde solution, in situ coupled the silane and phenolic during the polymerization reaction, and hybrid resin was obtained. Structure of the couple agent and hybrid resin was characterized by FTIR and NMR measurements. Through varying the amount of the couple agent, different morphology was obtained. The co-continuous structure of the cured hybrid with relatively higher amount of couple agent was confirmed by TEM and AFM observation, with the periodic length being about 50–65 nm. The oxidation resistance of the hybrid resin was greatly enhanced, the residual weight after oxidation at 1000 °C was much higher than that of pure phenolic resin. [ABSTRACT FROM AUTHOR]

In this article, the effects of nanorod–polymer interaction, aspect ratio of nanorods, block stiffness, and external tensile force on the microstructure and electrical properties of diblock copolymer nanocomposites have been investigated using molecular dynamics simulation. It is shown that, under suitable interactions of block-block and nanorod-block, a continuous localization of anisotropic nanorods in a continuous block with a slight uniaxial orientation can dramatically reduce the percolation threshold. Such effect is reinforced in the systems with high aspect ratio nanorods, but can be suppressed as block stiffness increases. Meanwhile, the external tensile strain breaks the continuity of the three-dimensional network but induces strong orientation along with the stretching direction, leading to a decrease of homogeneous probability and an increase of directional probability. [ABSTRACT FROM AUTHOR]

[Display omitted] • Mixed matrix membranes with co-continuous structures were fabricated. • UiO-66 nanoparticles preferentially localized in one of the continuous phases. • The gas permeation, gas sorption and gas diffusion properties were investigated. • Co-continuous structures enhanced the relative permeability of MMMs. • The CO 2 permeability increased by 635% for the MMM containing 35 wt% UiO-66. Membrane gas separation is considered a highly promising alternative to conventional gas separation. Recently, mixed matrix membranes containing UiO-66 metal–organic frameworks (MOFs) have been demonstrated to achieve high gas separation performance, especially in CO 2 -related separation. To date, few studies have used morphological control strategies to enhance the gas transport properties of mixed matrix membranes. In this study, we fabricated mixed matrix membranes comprising porous UiO-66 nanoparticles and immiscible 6FDA-based polyimide blends with co-continuous structures. The selective location of UiO-66 nanoparticles within one polymer phase of the co-continuous polymer blend was observed. However, this co-continuous structure cannot be referred to as a double-percolative morphology since the percolative UiO-66 networks did not successfully form. The gas permeability and gas sorption properties of pure gases (H 2 , CO 2 , N 2 , O 2 , and CH 4) in the dense membranes and mixed matrix membranes were measured using the constant-volume variable-pressure method and the dual-volume pressure decay method, respectively. On the basis of the solution–diffusion mechanism, the contributions of gas sorption and gas transport to the overall gas permeation properties were determined and examined. When the UiO-66 content reached 35 wt%, the CO 2 permeability of the mixed matrix membranes was significantly increased from 16.5 Barrer to 104.7 Barrer (by 635 %) without scarifying the permeability selectivities of CO 2 /N 2 (16.5 ± 1.5) and CO 2 /CH 4 (31.7 ± 5.8). The results suggest that both the addition of porous UiO-66 nanoparticles and the co-continuous structures contributed to the strongly enhanced gas separation performance of the mixed matrix membranes. [ABSTRACT FROM AUTHOR]

An ultra-glide twin screw extruder is employed to allow the quick and easy removal of the screws from the fixed processing section within few seconds, probing the current degree of the melting state, the dispersive anddistributive processing steps and finally the level of morphology development along extruder screws. For morphological studies the molten samples, collected from different points along the screw length, were quickly frozen in liquid nitrogen and observed under a scanning electron microscope. The morphology development along screws was studied for the compatibilized PA6/ABS blends with different ABS contents. It was observed that the co-continuous morphology was formed in an initial stage of mixing, which then transformed into a refined co-continuous structure and developed along the extruder. The level of co-continuity decreased at higher ABS content. In addition the effect of processing condition on morphology development was studied. In view of the mechanical properties, the effect of morphology on the impact strength could be elucidated. It was found that not only the co-continuous morphology but also the level of co-continuity plays an important role in determination of ultimate impact properties. The impact strength was lowered to 35 kJ/m2 from initial value of 47 kJ/m2 by increasing the ABS content from 60 to 70 wt%.

The electrically conductive nanocomposites composing of different concentrations (0.05–1.5 wt%) of reduced graphene oxide (RGO) in the thermoplastic polyurethane/polypropylene (TPU/PP, 55/40) matrix with a fine co-continuous structure were fabricated by solution-flocculation and melt-mixing process using a micron twin-screw extruder. Both thermodynamic and kinetic theoretical analysis predicated the preferential location of RGO in the TPU rather than PP phase. Both optical microscope and field emission scanning electron microscopy (FESEM) observations verified this theoretical dispersion predication. The homogeneous dispersion of RGO in the TPU matrix is confirmed by wide-angle X-ray diffraction (WAXD) patterns and transmission electron microscope (TEM) observation. A very low percolation threshold of 0.054 wt% was achieved owing to high conductivity of RGO and favorable double percolation effect. The tensile strength and elongation at break of the composites with RGO content of only 0.5 wt% were improved by 341.9% and 354.3%, respectively. The present work provides a guideline for an efficient, facile fabrication technique of graphene based conductive polymer nanocomposites with high electrical conductivity and improved mechanical properties. [ABSTRACT FROM AUTHOR]

An Al-5SiO2 (5 wt% of SiO2) aluminium matrix fiber composite was produced where the reinforcement consists of fossil silica fibers needles. After being heat-treated at 600 °C, the original fiber morphology was retained but its microstructure changed from solid silica to an interconnected (Al-Si)/Al2O3 interlaced structure named co-continuous composite. A technique of powder metallurgy, using commercial aluminium powder and the silica fibers as starting materials, followed by hot extrusion, was used to produce the composite. The co-continuous microstructure was obtained partially or totally on the fibers as a result of the reaction, which occurs during the heat treatment, first by solid diffusion and finally by the liquid Al-Si in local equilibrium, formed with the silicon released by reaction. The internal structure of the fibers was characterized using field emission electron microscope (FEG-SEM) and optical microscopy on polished and fractured samples.

ABSTRACT In this work, a solvent-free microsphere-templating process was developed to fabricate porous elastomers. The process starts with preparation of a porous wax template by thermal sintering at a temperature close to the wax melting temperature. Then, low-viscosity monomers for elastomeric polyurethane were cast into the wax template. Finally, after casting and curing of the elastomer, the wax component was removed by mechanical forces (centrifuge or squeezing) to produce a porous elastomer. With this process, polyurethane scaffolds with a co-continuous porous structure were successfully prepared. The optimal sintering temperature for the wax template was attained about 4°C below the wax peak melting temperature, leading to a stable process for joining wax microspheres into a three-dimensional porous template. Mechanistic approaches were found to be effective for extracting wax in the cast polyurethane; more than 90% of wax can be simply removed by mechanical squeezing above the wax melting temperature. After wax removal, the polyurethane demonstrated a morphology with micropores interconnected by microchannels, indicating the interconnectivity of the porous structure. Tensile tests showed that the resulting porous material is highly deformable and elastic, exhibiting typical properties of polyurethane elastomers. © 2012 Wiley Periodicals, Inc. Adv Polym Techn 2013, 32, 21330; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.21330 [ABSTRACT FROM AUTHOR]

Abstract: For the most part, ternary polymer blends demonstrate complete wetting behavior. Conceptually, this is the state where one of the components will always tend to completely separate the other two and from a thermodynamic viewpoint is described as the case where two of the three possible binary spreading coefficients are negative and the other is positive, as defined by Harkins spreading theory. This work examines the complete range of morphological states possible for such a system over the entire ternary composition diagram as prepared by melt mixing. A ternary polymer blend comprised of high-density polyethylene (HDPE), polystyrene (PS), and poly(methyl methacrylate) (PMMA) is selected as a model system demonstrating complete wetting and four sub-categories of morphologies can be identified including: a) matrix/core–shell dispersed phase; b) tri-continuous; c) matrix/two separate dispersed phases, and d) bi-continuous/dispersed phase morphologies. Electron microscopy as well as a technique based on the combination of focused ion beam irradiation and atomic force microscopy are used to clearly illustrate and identify the various phases. Solvent extraction/gravimetry is used to examine the extent of continuity of the systems so as to effectively identify regions of high continuity. Triangular compositional diagrams are used to distinguish these various morphological regions and the results are interpreted in light of the interfacial tension of the various binary combinations and their subsequent spreading coefficients. The effect of the molecular weight and of viscosity ratio on the phase size of the various structures is also considered. [Copyright &y& Elsevier]

In this work, the ternary shape-memory blends consisting of thermoplastic polyurethane (TPU), polylactic acid (PLA), and poly(propylene carbonate) (PPC) were prepared via direct melt blending. Due to the different compatibility, viscosity and surface tension, PLA and PPC coalesce into a compound phase (LPC) and then assembled with TPU to form a special co-continuous structure in each blend as the mass ratio of TPU and LPC fixed at 50:50, which was first predicted based on the spreading coefficient theory and then confirmed by SEM observation. Moreover, the morphology of PLA and PPC serving as switches and the interfacial area between TPU and LPC can be tailored through simply adjusting the composition of LPC, leading to the tunable dual- and triple-shape-memory effects (DSME and TSME). For DSME via regarding the whole LPC as the single switch, both the shape fixation and recovery ratios decline with decreasing the PLA content. It is revealed that replacing PLA with PPC not only weakens the mechanical support from LPC for holding temporary deformation but also reduces the interfacial area and thus the driving effect from TPU for shape recovery. When PLA and PPC respectively act as the switch to memorize the two temporary shapes, TSME can be realized and the property governed by phase morphology exhibits diverse variation trends at the different stages. By comparison, the blend containing 15 wt% PLA showed the best TSME, which was characterized both qualitatively and quantitatively. The simplicity of this strategy in fabricating polymeric materials with tunable multiple-shape-memory performances implies the scalability to other polymer pairs. [Display omitted] • Morphology control enables the formation of co-continuous structure in ternary blends. • Prediction of morphological structure based on the spreading coefficient theory. • Phase morphology and interfacial area could be tailored by a simply variation of mass ratio. • Tunable dual- and triple-shape memory effects were realized. • The operative shape-memory mechanism was systematically discussed. [ABSTRACT FROM AUTHOR]

Poly(phenylene oxide) (PPO)/polyamide 6 (PA6) (50/50 w/w) blend nanocomposites were prepared by melt mixing of PPO, PA6, and organically modified clay. The morphology of PPO/PA6 nanocomposite with various amounts of clay has been investigated using scanning electron microscope (SEM), transmission electron microscope (TEM), and wide-angle X-ray diffraction (WAXD). For the PPO/PA6 blend without clay, PPO is dispersed in the PA6 matrix with an average particle diameter of about 4.2μm. The domain size of the dispersed PPO phase is significantly decreased to about 1.1μm by adding a small amount of clay (2%). However, when the amount of organoclay is more than 5%, the matrix-domain structure is found to transform into the co-continuous morphology. The TEM observation shows that all the organoclay is dispersed only in the PA6 phase with a high degree of exfoliation and there is no any clay detectable in the PPO phase for the nanocomposites regardless of the amount of clay. It is considered that the dispersed clay platelets play an important role in the control of the PPO/PA6 blend morphology. Firstly, the selective localization of clay in PA6 phase changes the viscosity ratio of the PPO and PA6 phases. Therefore, clay has significant effects on the morphology of the polymer blend. Secondly, the high aspect ratio of the clay platelets prevents the coalescence of domains during melt mixing. [Copyright &y& Elsevier]

Polylactic acid/natural rubber/silicon dioxide thermoplastic vulcanizate with balanced stiffness-toughness had been fabricated in our previous work. To further elucidate the excellent impact strength of the co-continuous thermoplastic vulcanizate, a toughening model of the thermoplastic vulcanizate is established by imitating fiber distance theory in steel fiber reinforced concrete structure, which has a similar co-continuous structure. In addition, the other factors, such as the strength of the rubber phase and the interfacial adhesion between the two phases, are adopted to modify the model, which also have an intimate connection with the toughness of the composites. A quite good fit with Adj. R-Square of 0.94 is accepted. The construction of this model not only deepens the comprehension of toughening mechanism, but also provides a wind indicator for designing the super-tough composites with a co-continuous structure. Image 1 • The filler toughening model of co-continued structured TPV is the first time to put forward. • The influence of SiO 2 nanopaticles on the toughness of the co-continued structured TPV are quantified. • Defining and quantifying the influence factors of the toughness of the co-continued structured TPV. [ABSTRACT FROM AUTHOR]

High toughened polymeric materials have a wide application in many fields. Poly(methyl methacrylate) (PMMA) is a typical brittle polymer and it has been difficult to prepare high toughened PMMA material for a long time. To work on this issue, co-continuous phase structure was devised in PMMA/chlorinated polyethylene (CPE) blends through controlling the interfacial tension and viscosity in this work, resulting in the pronounced enhancement of impact toughness. The notched impact strength of co-continuous blends with 40 wt% CPE was up to 28.5 kJ/m2, increased by 26 times compared with pure PMMA. Selective extraction experiments, scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) showed that the CPE network was thin and weak when CPE addition was low, but became dense and strong once the content was more than 20 wt%. Two toughening mechanisms, i.e. cavitation and shear yielding, were put forward based on the micrographs of impact-fractured surfaces and double-notch four-point-bending test. This work may broaden the application prospects of PMMA and provide a new strategy to prepare high toughened polymeric materials through fabricating co-continuous in polymer blends. Image 1 • Co-continuous phase structure was devised in PMMA/CPE blends. • The impact strength of PMMA/CPE blends was 26 times higher than that of pure PMMA. • Low interfacial tension and equal viscosity were main reason for phase formation. • Two toughening mechanisms, i.e. cavitation and shear yielding, were put forward. • This work provides a new strategy to prepare high toughed polymer materials. [ABSTRACT FROM AUTHOR]

Novel, fully biobased shape memory thermoplastic vulcanizates (TPVs) were prepared using two sustainable biopolymers, poly(lactic acid) (PLA), and modified natural Eucommia ulmoides gum (EUG-g-GMA), via a dynamic vulcanization technique. Simultaneously, in situ compatibilization was achieved in the TPVs to improve interfacial adhesion and the crosslinked modified Eucommia ulmoides gum (EUG) was in "netlike" continuous state in the PLA matrix to form "sea-sea" phase structure. The promoted interface and co-continuous structure played critical roles in enhancing shape memory capacity and toughness of the TPVs. The TPV with 40 wt % modified EUG displayed the highest toughness with an impact strength of 54.8 kJ/m2 and the most excellent shape memory performances with a shape fixity ratio (Rf) of 99.83% and a shape recovery ratio (Rr) of 93.74%. The prepared shape memory TPVs would open up great potential applications in biobased shape memory materials for smart medical devices. [ABSTRACT FROM AUTHOR]

In this study, selective distribution of amino-functionalized multi-walled carbon nanotubes (MWCNTs-NH 2) in poly (vinylidene fluoride)/polyamide 6 (PA6/PVDF) blends is achieved via the mixing process and subsequent migration. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and selective extraction confirmed that MWCNTs-NH 2 could migrate from the PVDF phase to the two-phase interface. The composites could significantly improve thermal/electrical conduction capacity of the composites with low dose. The thermal infrared characterization also indicated that the composites have better heat absorption capability and dissipation performance due to the good thermal conductivity. Rheological measurements exhibited the MWCNTs-NH 2 could form network structure with a low content at the interface of the composites. Moreover, the addition of MWCNTs-NH 2 led to an improvement in the mechanical properties compared with the pure PA6/PVDF blends. These results manifest that the thermal/electrical conductivity and mechanical performance of the composites with low filler loading can be significantly improved by selective distribution of MWCNTs-NH 2 through controlling the migration process. Unlabelled Image • MWCNTs-NH 2 were introduced into PVDF/PA6 blends by different mixing processes • MWCNTs-NH 2 could be selectively distributed at interface of the polymer blends through controlling the blending process • The composites exhibited improvement of thermal/electrical conductivity and mechanical properties when the MWCNTs-NH 2 distributed at interface of the polymer blends [ABSTRACT FROM AUTHOR]

In this study, the co-continuous blends of polypropylene (PP) and ethylene propylene diene rubber (EPDM) were prepared. Boron nitride (BN) nanoparticles were introduced into PP/EPDM blends by different blending processes to prepare the thermal composites. Solvent extraction, thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) were used to investigate the location of BN in the immiscible polymer blends. Through controlling the blending process, the BN nanoparticles could be selectively distributed at the PP phase, EPDM phase or interface of the polymer blends. The results showed that BN selectively located in the PP phase can achieve have the highest thermal conductivity when the BN nanoparticles were firstly mixed with PP phase. In addition, the influence of the different mass ratio of PP and EPDM on the thermal properties was also investigated. The blends with the mass ratio of PP/EPDM 50/50 have the highest thermal conductivity. • BN nanoparticles were introduced into PP/EPDM blends by different mixing processes. • Solvent extraction and TGA were used to investigate the location of BN. • BN location could be tuned through controlling the blending process. • The blends with the mass ratio of PP/EPDM 50/50 have the highest thermal conductivity. [ABSTRACT FROM AUTHOR]

In this study, the in-situ compatibilization reaction between recycled acrylonitrile–butadiene–styrene copolymer (rABS) and functional styrene–ethylene–butylene–styrene block maleic anhydride (SEBS-g-MAH) was confirmed, which contributed to the toughening phenomenon of rABS, especially the notched impact strength. As mechanical test that manifested, the rABS/SEBS-g-MAH blends are stronger and more ductile than the rABS/SEBS blends. Prominently, the former has great advantage over the latter in terms of improving the impact performance. Scanning electron microscope (SEM) images showed that the compatible segments that were generated by reaction not only improve the interface adhesion of rABS/SEBS-g-MAH blends but also promote the evolution of co-continuous structures, which can be evidently observed after etching. Furthermore, the SEM micrographs of tensile fracture surfaces indicated that the formation of the co-continuous phase and the improvement of interface adhesion are the most profound reasons for the excellent tensile properties of the rABS/SEBS-g-MAH blends. The impact fracture surface revealed that two-phase interface affects crack propagation and shear yielding absorbs more impact energy than simple interface debonding does at higher deformation rates. Meanwhile, rheological analysis demonstrated that the complex viscosity of the rABS/SEBS-g-MAH (80/20 wt%) blend with a co-continuous structure exhibits a maximum positive deviation at low frequencies from the theoretical value calculated using the rule of logarithmic sum, which indicated a connection between co-continuous structure and complex viscosity. In addition, the storage modulus vs. loss modulus curves of the blends revealed that the viscoelastic behavior of rABS/SEBS-g-MAH blends is very similar to that of rABS. [ABSTRACT FROM AUTHOR]

Carbon black (CB)-filled polypropylene (PP) with surface resistivity between 10 6 and 10 9  Ω sq -1 is the ideal antistatic plastic material in the electronics and electric industry. However, a large amount of CB may have an adverse effect on the mechanical properties and processing performance of the material, thus an improved ternary system is developed. Blends of CB-filled PP and polyamide 6 (PA6) have been prepared by melt blending in order to obtain electrically conductive polymer composites with a low electrical percolation threshold based on the concept of double percolation. The morphological developments of these composites were studied by scanning electron microscopy. The results showed that CB particles were selectively dispersed in PA6 phases due to the good interaction and interfacial adhesion between CB and PA6. At the same CB loadings, the surface resistivity of PP/PA6/CB composite was smaller than that of PP/CB composite system, which indicated the better conductivity in the former composite. The increasing amount of PA6 in the composites changed the morphology from a typical sea-island morphology to a co-continuous morphology. What is more, with 8 wt% of CB and PP/PA6 phase ratio of 70/30 in which the PP and PA6 phases formed a co-continuous structure, the electrical conductivity of the composite peaked at 2.01 × 10 5  Ω sq -1 ., Competing Interests: We declare we have no competing interests.