Interfacial Adhesion Properties Research Articles

Characterization of Waste Micro and Nano Tungsten Carbide Powder Reinforced Polyamide 66 Matrix Composites

Polyamide 66 (PA 66) or Nylon 66 is a strong, easily processed polymer with high thermal resistance and excellent mechanical properties. Tungsten carbide (WC/Co-Cr 86/10-4), known for its exceptional hardness and elasticity, is commonly used for coatings in the thermal spraying and coating industry. In this study, we examined the microstructural, mechanical, and thermal properties of composites made from waste micro and nano WC/Co-Cr 86/10-4 powder and a PA66 matrix. PA66 was reinforced with varying ratios of 3, 6, and 10 wt.% WC/Co-Cr 86/10-4. The composite specimens were created by mechanically mixing granular PA66 and micro and nano WC/Co-Cr 86/10-4 powders and molding them under controlled temperature. Mechanical properties were evaluated through ductility and hardness tests, while thermal properties were determined through DSC analysis. The SEM observation revealed the distribution of WC/Co-Cr 86/10-4 within the polymer matrix. The DSC analysis indicated that the composite had a slightly higher melting temperature than pure PA66, and the thermal conductivity also increased slightly. The experimental results demonstrated that the mechanical properties of the composite improved as the WC/Co-Cr 86/10-4 content increased, specifically in terms of tensile strength and hardness. Additionally, the composite exhibited enhanced interfacial adhesion, mechanical behavior, and thermal properties. This composite, utilizing WC/Co-Cr 86/10-4 waste and recycled PA66, allows for the repurposing of industrial waste.

The peeling behavior of a heterogeneous elastic film on a rigid substrate

Although the interfacial peeling behavior of a homogeneous film-substrate system is well understood, the peeling process of a heterogeneous elastic film bonded to a rigid substrate is still unclear. In the present paper, the peeling behavior of a heterogeneous film adhering on a rigid substrate under a vertical peeling force is investigated theoretically, in which the film’s heterogeneity is characterized by the change of bending stiffness along the length of the film. Based on the principle of minimum potential energy, the typical relationship between the peeling force and the peeling displacement during the whole peeling process is achieved. Different from the homogeneous film case, the peeling force can be regulated dramatically by the film’s heterogeneous bending stiffness during the peeling process. When the interfacial debonding front propagates from a compliant segment to a stiff segment, the peeling force is enhanced; while the peeling force is weakened as the interfacial debonding front goes from a stiff segment to a compliant one. The enhancement or weakening of the peeling force depends not only on the bending stiffness of each segment of the film but also on the bending stiffness ratio of neighboring segments, as well as the adhesion length of each segment and the interfacial adhesion properties. The mechanism underlying the heterogeneity-induced tunable peeling force is further elucidated by the change rate of elastic bending energy stored in the film and energy overcoming the interfacial interaction potential during the peeling process. The transfer and redistribution of the elastic bending energy are the main factors that induce the change of peeling force as the interfacial debonding front reaches the boundary of neighboring segments with different bending stiffness. The results of this paper can provide a new strategy for designing film-substrate systems with adjustable adhesion without changing the interfacial characteristics.

Damage on asphalt surfaces caused by ionic solution erosion and salt crystallization at molecular scale

The damage mechanism of severe salt corrosion on asphalt surfaces should be revealed at molecular scale. This study utilized molecular dynamics (MD) and density functional theory (DFT) simulations to investigate damage degree and mechanism of ionic solution erosion and salt crystallization on asphalt surfaces. Various asphalt-solution and asphalt-salt interfaces models were built, while interfacial interaction, diffusion, adhesion, and electronical properties were calculated. The electrostatic interaction played a critical role both in solution-asphalt and crystal-asphalt systems, particularly between anions and asphalt. All ions adsorbed onto unaged asphalt surfaces and eroded into unaged asphalt interiors while only cations penetrated into aged asphalt due to electronical repulsions between anions and SO/CO, indicating cation erosion contributed more to salt damage during aging. Salt crystals participated and expanded on asphalt surfaces, resulting in micro-cracks and micro-voids. Sulfates adhered asphalt more than chlorides because sulfates had closer interval distance and larger free volumes with asphalt. Asphalt molecules with high polarity and more charge were more susceptible to interact by ions. The salt damage on asphalt mainly included solution perpetration and crystal adhesion. The order of salt damage of cations to asphalt is: Mg2+ > Na+ > Ca2+, and of anions is: SO42− > Cl−.

Effects of reactive elements and Pt doping on the adhesive strength and tension property of α-Al2O3/γ'-Ni3Al-S interface

The enhancement of cyclic oxidation performance in ultra-high temperature protective coatings for turbine blades in new generation aero-engines can be achieved through the reactive elements or Pt doped β-NiAl single phase. However, it is important to note that the content of Al in NiAl gradually decreases during high temperature service, leading to an inevitable phase transition from β-NiAl to γ’-Ni3Al. We only studied the reactive element effects on the adhension and stability of the α-Al2O3/β-NiAl interface previously, but the influence mechanism for α-Al2O3/γ'-Ni3Al interface is not clear. Therefore, it is imperative to investigate the adhension and stability of the γ’-Ni3Al/oxide interface. This paper investigates the effect of Pt or reactive elements (Hf, Zr, Dy, Y, La) doping on the α-Al2O3/γ'-Ni3Al interfacial adhesion and tensile properties with or without impurity element S, using the first-principles calculation method. The results indicate that the influence of Pt or REs doping on interface adhension is contingent upon the existence of S, and the effect on static interface bonding or dynamic tensile properties varies as well. It will improve the comprehensive design system of Ni-Al coatings, and provide theoretical guidance for the development of new metallic protective coating materials.

Effects of freeze–thaw cycles on micro and meso-structural characteristics and mechanical properties of porous asphalt mixtures

Abstract Porous asphalt concrete (PAC) have a typical big void-skeleton structure, and porous asphalt mixtures with large voids are more prone to freeze–thaw damage. As a result, research on the influence of freeze–thaw cycles on the micro-structure and mechanical characteristics of porous asphalt mixes offers a theoretical framework for overcoming water stability concerns in porous asphalt mixtures in practice, as well as for further popularization and application. In this study, styrene–butadiene–styrene (SBS)-modified asphalt and high viscosity modified asphalt were constructed on the basis of the original asphalt, and the mix proportions of asphalt mixes PAC-13, AC-13, and SMA-13 were designed. To begin, molecular dynamics simulations were used to look into the effects of freeze–thaw cycles on asphalt–aggregate interface adhesion and mixture micro-mechanical properties. Second, the effects of freeze–thaw cycles on the void characteristics of porous asphalt mixtures were explored utilizing digital image processing technologies. Finally, the freeze–thaw split test was utilized to evaluate the macroscopic mechanical properties of a porous asphalt mixture after freezing and thawing cycles. According to the study findings, high viscosity modified asphalt made with 4% SBS/8% TPS has the greatest performance. The application of SBS/TPS-modified asphalt can considerably improve the damage resistance of porous asphalt mixes. The micro-structure and mechanical qualities of porous asphalt mixtures are damaged by freeze–thaw cycles, and the damage gets worse as the number of cycles rises. The study’s conclusions provide a theoretical justification for the application of porous asphalt pavement.

Reversible surface modification of PAN-based carbon fibers by a ferrocene-based surfactant

The surface of carbon fibers (CFs) was modified by a surfactant (ferrocenemethyl)dodecyldimethylammonium bromide (FDDA) to enhance the interfacial ashesion between the CFs and surrounding matrix. Results showed that it could be electrochemically desorbed by a potentiostatic electro-oxidation method. The FDDA adsorption isotherm was attributed to the formation of multi-molecular layers mainly by non-electrostatic interactions. The adsorption and desorption of FDDA on the CFs have little effect on their tensile strength. The effects of FDDA modification on the interfacial properties of CF/epoxy composites were evaluated by a single-filament fragmentation test. Compared with the un-modified CFs, the FDDA-modified ones had significantly improved interfacial adhesion properties in the composites. This method provides a potential approach for preparing recyclable CF/resin composites.

Tuned Reactivity at the Lithium Metal–Argyrodite Solid State Electrolyte Interphase

AbstractThin intermetallic Li2Te–LiTe3 bilayer (0.75 µm) derived from 2D tellurene stabilizes the solid electrolyte interphase (SEI) of lithium metal and argyrodite (LPSCl, Li6PS5Cl) solid‐state electrolyte (SSE). Tellurene is loaded onto a standard battery separator and reacted with lithium through single‐pass mechanical rolling, or transferred directly to SSE surface by pressing. State‐of‐the‐art electrochemical performance is achieved, e.g., symmetric cell stable for 300 cycles (1800 h) at 1 mA cm−2 and 3 mAh cm−2 (25% DOD, 60 µm foil). Cryo‐stage focused ion beam (Cryo‐FIB) sectioning and Raman mapping demonstrate that the Li2Te–LiTe3 bilayer impedes SSE decomposition. The unmodified Li–LPSCl interphase is electrochemically unstable with a geometrically heterogeneous reduction decomposition reaction front that extends deep into the SSE. Decomposition drives voiding in Li metal due to its high flux to the reaction front, as well as voiding in the SSE due to the associated volume changes. Analysis of cycled SSE found no evidence for pristine (unreacted) lithium metal filaments/dendrites, implying failure driven by decomposition phases with sufficient electrical conductivity that span electrolyte thickness. DFT calculations clarify thermodynamic stability, interfacial adhesion, and electronic transport properties of interphases, while mesoscale modeling examines interrelations between reaction front heterogeneity (SEI heterogeneity), current distribution, and localized chemo‐mechanical stresses.

Effect of coating thickness on interfacial adhesion and mechanical properties of Cr-coated zircaloy

The tensile failure behavior of the Cr-coated zircaloy (Zr-4) was investigated. The effect of the coating thickness on the interfacial adhesion of the samples was studied by observing the real-time process of tensile. The interfacial adhesion of the Cr coating was quantitatively evaluated using finite element analysis and shear strength theory. In addition, the crack propagation behavior of the Cr-coated samples was investigated. Results showed that the interfacial shear strength and the interfacial adhesion performance decreased with the increase of the coating thickness. However, the protective effect on the substrate increased with the increase of the coating thickness. Furthermore, the path of the crack propagation at the interface between the coating and the substrate also changed as the coating thickness increased. The cracks at the interface of the thinner coating expanded easily into the substrate, causing the local damage. The cracks of the thicker coating were more likely to propagate along the interface, resulting in the adhesive failure.

Curing Kinetics and Mechanical Properties of Epoxy-Cyanate Ester Composite Films for Microelectronic Applications.

In general, although abundant literature studies are available on epoxy resin systems, a complete description of the curing kinetics in epoxy-cyanate ester composites relevant to the microelectronics industry is still lacking. Herein, curing behaviors of Ajinomoto build-up films, which are epoxy/silica composites, were studied by the non-isothermal differential scanning calorimetry method, and then, three non-isothermal curing kinetics models and model-free curing methods were used to analyze curing behaviors. In addition, a copper layer was also deposited onto the surface of the build-up film, and its interfacial adhesion property was also analyzed at different pre-curing conditions. The results showed that the curing reaction of the build-up film contains two curing reaction processes, and the first curing process is suited for the autocatalytic curing model, while the other curing process is suited for the Kamal curing kinetics model. Three model-free curing methods were used to calculate the activating energy at different degrees of curing, which indicated that the activating energy is variable during the whole curing process. The interfacial adhesion strength between the build-up film and copper layer decreased with the increase in the degree of curing, which is attributed to the contribution of mechanical anchoring. This work will offer guidance in curing behaviors for improving interfacial bonding force and controlling warpage behavior for chip substrates in the future.

Comparing four kinds of lignocellulosic biomass for the performance of fiber/PHB/PBS bio-composites

A new class of bio-composites was developed by utilizing four kinds of lignocellulosic biomass fiber (bagasse, bamboo, rice husk, and rice straw) as filling fibers. Poly-β-hydroxybutyrate (PHB) and poly(butylene succinate) (PBS) in a mixture ratio of 7:3 were used as matrix materials with hot-press molding. The performance of the resulting composites was evaluated by compositional analyses, mechanical analysis, Fourier transform infrared (FTIR) spectroscopy, thermogravimetry, and morphological analysis. The interfacial adhesion, thermal stability, and comprehensive mechanical properties of the alkali treated bamboo/PHB/PBS composite were highest among the four bio-composites. The bending strength, tensile strength, and impact strength for alkali treated bamboo/PHB/PBS composite was 19.82 MPa, 12.97 MPa, and 4.30 kJ/m2, respectively. The thermal stability for NaOH modified bamboo/PHB/PBS composite was slightly superior to the other three composites, with the initial pyrolysis temperature of 248 °C, moderate pyrolysis speed, and the amount of pyrolysis residue (5.81%). The results showed the suitability of biomass fiber and biodegradable polymer for producing environmentally friendly composite materials.

Evaluating the interfacial properties between crumb rubber modified asphalt and aggregates using molecular dynamics simulation methods

In the present study, the molecular dynamics (MD) simulation methods were used to investigate the interfacial properties of crumb rubber modified asphalt (CRMA)-aggregates considering the effects of crumb rubber (CR) degradation behavior and moisture. The interface models with different CR degradation degrees were then constructed. The interfacial adhesion properties between CRMA and aggregates were discussed by the interaction energy and work of adhesion; the agglomeration characteristics of CRMA on aggregates surface were evaluated by the radial distribution function (RDF); the diffusion behaviors of CRMA on aggregates surfaces were investigated using the mean square displacements (MSD); the asphalt adhesion strength test was performed to further verify the reliability of the simulation results. The results showed that the incorporation of CR into asphalt could significantly improve the adhesion and moisture damage resistance of the asphalt mixtures, while the CR degradation would slightly decrease these properties. The results of asphalt adhesion strength test exhibited similar trends with those of the work of adhesion, indicating that the simulation possessed a certain rationality. The RDF curves showed that the intrusion of water enlarged the distance between the polar components and aggregates, whereas the CR molecules displayed satisfactory agglomeration properties. Furthermore, the addition of CR weakened the mobility of asphalt on aggregates surface. This was mainly attributed to the poor mobility of the CR and its limitation on the mobility of the constituent components of asphalt. However, these problems would be alleviated as the CR degradation.

Electronic characteristic, tensile cracking behavior and potential energy surface of TiC(111)/Ti(0001) interface: A first‑principles study

The preparation of TiC coating on Ti alloy surface to improve the wear resistance has attracted attention from researchers in aerospace field. The service life of TiC coating is related to the interfacial adhesion properties between TiC coating and Ti alloy substrate. However, it is difficult to explain its interfacial adhesion mechanism by experimental methods. Based on the termination of atoms on the TiC surface, two TiC/Ti interface models named as the C-terminated-TiC(111)/Ti(0001) and Ti-terminated-TiC(111)/Ti(0001) interface were constructed by first-principles. The interfacial electronic characteristic of C—Ti bond is a mixture of polar covalent and metal bonds, and that of Ti—Ti bond is the metal bond. The tensile strains of both C-terminated-TiC(111)/Ti(0001) and Ti-terminated-TiC(111)/Ti(0001) interface in the fracture stage are ranged from 12% to 14%. Their maximum tensile stresses are 16.201 GPa and 15.590 GPa, respectively. The sliding potential energy surface maximum of C-terminated-TiC(111)/Ti(0001) and Ti-terminated-TiC(111)/Ti(0001) interface are 5.387 J/m2 and 0.271 J/m2, respectively. And the sliding potential barriers on the minimum energy path are 2.094 J/m2 and 0.136 J/m2 with an ideal shear strength of 20.32 GPa and 1.61 GPa, respectively. In summary, the interfacial adhesion property of C-terminated-TiC(111)/Ti(0001) interface is better than that of Ti-terminated-TiC(111)/Ti(0001) interface.

Comparative analysis of hydrothermal properties of ramie fiber‐reinforced phenolic resin and ramie fiber‐reinforced unsaturated polyester composites

AbstractRamie fiber‐reinforced polymer (RFRP) composites are widely used in various fields owing to their environmental friendliness and cost efficiency. To understand the influence of different resin matrices on the mechanical properties and durability of RFRP composites under the same conditions and obtain better performance, ramie fiber‐reinforced phenolic resin (RFRPR) composites and ramie fiber‐reinforced unsaturated polyester (RFRUP) composites produced through compression molding were studied under hydrothermal conditions of 60°C with 50%, 85%, and 98% relative humidity for 3 months. The water absorption, tensile, flexural, and short‐beam shear properties were studied. The RFRPR composite had better flexural strength and short‐beam strength than the RFRUP composite. The saturated water absorption, water molecule diffusion coefficient, and retention rate of the RFRUP composite were higher than those of the RFRPR composite owing to the difference in the interfacial adhesion properties. The erosion of water molecules led to serious deterioration in the interfacial bonding performance of the RFRPR composite. It was found that the greater the humidity, the greater was the degree of interfacial degradation. This study lays the foundation for the further promotion and application of RFRP composites.

Decohesion of graphene from a uniaxially-stretched substrate: Failure analysis of a frictional adhesive interface

Composite structures consisting of two-dimensional (2D) materials deposited on elastic substrates have a wide range of potential applications in flexible electronics. For such devices, robust 2D film/substrate interfacial adhesion is essential for their reliable performance when subjected to external thermal and mechanical loads. To better understand the strength and failure behavior of the 2D film/substrate interfaces, two types of graphene/polymer samples with distinct interfacial adhesion properties are fabricated and tested by uniaxially stretching the substrates. Depending on the interfacial adhesion, two drastically different debonding rates are observed, i.e., rapid snap-through debonding and more progressive crack propagation. Motivated by the experimental observation, we propose an improved shear-lag model with a trapezoidal-shaped cohesive zone to derive an analytical solution for the decohesion behavior. The theoretical model reveals that the decohesion behavior of the frictional adhesive interface is governed by three dimensionless parameters. Particularly, the dimensionless length of the film essentially determines the decohesion rate; while the other two parameters affect the critical substrate strain to initiate debonding. By fitting the experimental data with the theoretical model, the intrinsic adhesion properties of the two samples are obtained with physically meaningful values. This work offers an analytical solution to describing the decohesion behavior of general thin film/substrate systems with a frictional adhesive interface, which is beneficial for characterizing and optimizing the mechanical properties of various thin film/polymer devices.

Interfacial Adhesion Property of Asphalt Binder with Calcium Alginate Carrier of Asphalt Rejuvenator.

Recently calcium alginate has been successfully applied to encapsulate asphalt rejuvenator, which can protect asphalt rejuvenator from early leakage and release asphalt rejuvenator when triggered by specific factors such as cracks. The interfacial adhesion property of asphalt binder with calcium alginate carrier is of great importance to its actual performance. In this paper, the molecular model of the interface region between asphalt binder and calcium alginate was established, and molecular dynamics simulations were performed on it to investigate the molecular interaction at the interface region. By extracting and processing the data during the simulation process, the interfacial adhesion behavior was expounded using the spreading coefficient (S), permeation depth and permeation degree. Furthermore, the interfacial adhesion strength was evaluated by adopting the interfacial adhesion work. Results showed that the value of S was greater than 0, implying that asphalt binder could wet the surface of calcium alginate. Saturate had the highest value of permeation degree, followed by resin, aromatic and asphaltene. However, asphalt binder could not infiltrate into the interior of TiO2, only accumulating and spreading on the surface of TiO2. The interfacial adhesion work of unaged and aged asphalt binder to calcium alginate was -114.18 mJ/m2 and -186.37 mJ/m2, respectively, similar to that of asphalt-aggregate interface. The van der Waals interactions contributed the most to the formation of the interfacial adhesion strength. In addition, a certain degree aging of asphalt binder and addition of titanium dioxide in the calcium alginate carrier were helpful to enhance the interfacial adhesion strength.

In-situ study on the tensile property and fracture behavior of Cr coating for nuclear fuel cladding

It has been suggested that Cr-coated zircaloy is an excellent material for accident-tolerant fuel (ATF) cladding. It is found that Cr coating shows multi-cracking behavior under external load due to its embrittlement. Different fabrication parameters will lead to different crack resistances of the coatings, but the brittle cracking characteristic is common. The estimation of the strength and structural integrity of the fuel cladding depend on the cracking characteristic of the coating. The Cr coating’s tensile characteristic for ATF cladding was examined utilizing the in-situ mechanical testing method. The surface crack initiation, propagation, and fracture process were captured in real time, and the crack density evolution of two different process parameters was compared. The results demonstrate that the first long channel crack occurs at a small strain, then the crack density increases rapidly and gradually reaches saturation with increasing stress. Different fabrication parameters will change the cracking resistance. Compared with the previous sample, the new sample started to crack at a larger strain, the crack density reached saturation faster with a larger saturated crack density, and the crack resistance is inferior. Many small cracks in different directions were observed near the fracture surface. Moreover, there was no interfacial spallation under stress, demonstrating the Cr coating’s excellent interfacial adhesive property.

Highly Stable Liquid Metal Conductors with Superior Electrical Stability and Tough Interface Bonding for Stretchable Electronics.

Ga-based liquid metal stretchable conductors have recently gained interest in flexible electronic devices such as electrodes, antennas, and sensors. It is essential to maintain electrical stability under strain or cyclic strain for reliable data acquisition and exhibit tough interfacial bonding between liquid metal and polymers to prevent performance loss and device failure. Herein, a highly stable conductor with superior electrical stability and tough interface bonding is introduced by casting curable polymers and a peeling-activated process from liquid metal particles. Based on the compensating effect of liquid metal, similar to the recharge relationship of water between rivers and lakes in nature, the conductor is not only strain-insensitive (ΔR/R0 < 10% for 100% strain) but also immune to cyclic deformation (ΔR/R0 < 7% with 5000 stretching cycles at 50% strain). Embedding liquid metal within the elastomer to create stretchable conductors effectively improves interfacial adhesion properties (the fluid-solid interfacial adhesion force increases from 0.48 to 0.62 mN/mm2). The constructed tough interface could even withstand sonication treatment. Finally, by combining strategies in material design and fabrication, an integrated array composed of vertical interconnect access and robust electrodes is fabricated, which simultaneously holds tough interfacial bonding with the upper and lower layers.

Analytical and experimental investigation of the mode-II energy release rate of electrodes using a plasticity-assisted zero-degree peeling configuration

Lithium-ion batteries integrate heterogeneous materials such as active layers and current collectors, resulting in interfaces prone to delamination during the charge/discharge process. The mode-II energy release rate is a key index to evaluate the interfacial adhesion properties and structural integrity of electrodes. In this study, an analytical model considering the energy balance principle and a nonlinear constitutive model was established to characterize the mode-II energy release rate. A novel plasticity-assisted zero-degree peeling test (PAZDPT) is proposed to obtain a stable crack propagation stage where the peeling force is determined to calculate the mode-II energy release rate. Several parameter studies were conducted to verify the approximation of the stress distributions and simplification of the analytical model. The accuracy of the analytical model was validated against finite-element calculations. The results demonstrated an excellent agreement between the theoretical calculation and numerical results. Moreover, PAZDPT is conducive to steady crack propagation because it restricts the energy accumulation around the crack tip. The analytical model and newly proposed PAZDPT can also be extended to determine the mode-II energy release rate of other types of interfaces in bilayer thin-film materials.

Effect of dynamic water pressure on the adhesion behavior of recycled asphalt-aggregate interface by molecular dynamics method

The integrity of the asphalt-aggregate interface is challenged by the dynamic water pressure under traffic loads, especially for recycled asphalt mixtures that represent lower moisture damage resistance by comparing with virgin asphalt mixtures. The effect of dynamic water pressure on the microscale interfacial adhesion properties between the waste-oil recycled asphalt and aggregate was comprehensively investigated based on the molecular dynamic simulation. The molecular models of recycled asphalt and aggregate were calibrated based on the chemical and physical analysis in experiments. The interfacial contact models between recycled asphalt with different regenerants (waste cooking oil-WCO, waste vegetable oil-WVO, and waste engine oil-WEO) and basalt aggregate were established, which also incorporated the thermodynamic process of water intrusion into the interface. The interface behaviors were studied by analyzing the cohesion energy of asphalt, the adhesion energy of interface, and the distribution of asphalt and water concentration on the aggregate surface. The results demonstrated that the dynamic water pressure can accelerate the water to penetrate the asphalt film. The recycled asphalt was pushed away from the basalt aggregate surface after the water film was formed at the interface, where the four components of asphalt leave the interface at different rates. Compared with the other two kinds of waste-oil recycled asphalt and conventional recycled asphalt, the WEO recycled asphalt-aggregate interface represented the optimum moisture damage resistance. The decrease of interface adhesion energy is about 55.7 % subjected to the coupling effects of the high-temperature and dynamic water pressure at 0.5 MPa.

Improving interfacial adhesion and mechanical properties of carbon fiber reinforced polyamide 6 composites with environment-friendly water-based sizing agent

In this study, a water-based aminoethylpiperazine-polyamide (AEPPA) is synthesized and its water-based sizing agent is prepared to improve the interfacial properties of carbon fiber reinforced polyamide 6 (CF/PA6) composites. The results show that the AEPPA sizing layer enhances the wettability of CF surface, thereby promoting the sufficient impregnation of PA6 resin on the fiber surface. Meanwhile, a strong interface is formed due to the interdiffusion and hydrogen bond formation between AEPPA and PA6 molecular chains. Accordingly, the interfacial shear strength increases by 29.3% and 20.2% from 41.9 MPa for as-received and 45.1 MPa for desized CF/PA6 composites to 54.2 MPa for 4 wt% AEPPA sizing agent treated CF/PA6 composites. In addition, to clarify the applicability of the resultant sizing agent, unidirectional CF/PA6 prepregs are prepared, and the mechanical properties of CF/PA6 composites are evaluated in detail. The average interlaminar shear strength, tensile strength and flexural strength increase by 14.2%, 10.5% and 20.0% from 73.8, 2198.1 and 1393.6 MPa for desized CF/PA6 composites to 84.3, 2638.7 and 1539.9 MPa for those treated with AEPPA sizing agent due to the effective stress transfer across the interface, respectively. Moreover, the cross-section morphologies and fracture behavior are analyzed to verify the improvement of mechanical properties. Furthermore, the strengthening mechanism of interfacial properties is intensively discussed.