Aminosilane Coupling Agent Research Articles

In Situ Growth of Highly Compatible Cu2O-GO Hybrids Via Amino-Modification for Melt-Spun Efficient Antibacterial Polyamide 6 Fibers.

Polyamide 6 (PA6) fiber has the advantages of high strength and good wear resistance. However, it is still challenging to effectively load inorganic antibacterial agents into polymer substrates without antimicrobial activity. In this work, graphene oxide is used as a carrier, which is modified with an aminosilane coupling agent (AEAPTMS) to enhance the compatibility and antimicrobial properties of the inorganic material, as well as to improve its thermal stability in a high-temperature melting environment. Cuprous oxide-loaded aminated grapheme (Cu2O-GO-NH2) is constructed by in situ growth method, and further PA6/Cu2O-GO-NH2 fibers are prepared by in situ polymerization. The composite fiber has excellent washing resistance. After 50 times of washing, its bactericidal rates against Bacillus subtilis and Escherichia coli are 98.85% and 99.99%, respectively. In addition, the enhanced compatibility of Cu2O-GO-NH2 with the PA6 matrix improves the orientation and crystallinity of the composite fibers. Compared with PA6/Cu2O-GO fibers, the fracture strength of PA6/Cu2O-GO-NH2 fibers increases from 3.0 to 4.2 cN/dtex when the addition of Cu2O-GO-NH2 is 0.2wt%. Chemical modification and in situ concepts help to improve the compatibility of inorganic antimicrobial agents with organic polymers, which can be applied to the development of medical textiles.

Recycling of expired cow milk for constructing multifunctional biomass nonfluorinated chromatic paint with superhydrophobicity

Through denaturation and amination of the mixture, consisted of expired cow milk, kaolin and gardenia yellow, in the hot organic solvent that contained alkaline aminosilane coupling agent, then adsorption of diverse acid dyes in the acid condition, thus obtaining active matrixes with different colors. By virtue of the non-catalyzed in-situ reaction among the acrylate groups of pentaerythritol ester compounds and the amino groups of obtained matrixes as well as long-chain alkyl amines, the biomass fluoride-free superhydrophobic doped paints was prepared, however the poor stability was reflected in its anti-wetting coating surface. Furthermore, in order to improve durable superhydrophobicity and multifunctionality of the expired cow milk-based water-repellent paint, the thermally denatured protein, originated from expired cow milk heating, was blended with nanoscale inorganic pigments to accept the before-mentioned procedures of amination and in-situ growth, consequently constructing the multifunctional biomass nonfluorinated chromatic paint with robust superhydrophobic function, moreover its coated fabrics had 155.7° of average contact angle and 1.5° of average sliding angle. Additionally, by only using synergy of complex denaturation and chemical coupling, the expired cow milk could be transformed into UV-photoluminescent nonfluorinated superhydrophobic color paint, the contact angle of such paint-coated fabric was 153.3° and its sliding angle was 2°. Based on the additional function of as-prepared biomass paints, the applications of non-wetted switchable fluorescence imaging as well as photothermal deicing were realized. We believe that the expired cow milk-based multifunctional paints can expand into the fields of outdoor protective textiles, decorative building materials, fluorescent falsification-preventing and ice protection.

Minimizing usage of silane coupling agent for amine-grafted mesoporous silica CO2 adsorbent

Amine-grafted adsorbents are promising CO2 adsorbents; however, the excessive addition of an amino silane coupling agent during their synthesis increases their production cost. Thus, using low amounts of silane, we synthesized 3-aminopropyltrimethoxysilane (APTMS)-grafted SBA-15 mesoporous silica and evaluated its CO2 adsorption performance. APTMS-grafted SBA-15 samples were prepared using either impregnation or heating–filtration method (grafting). The obtained samples were characterized by X-ray diffraction spectroscopy, transmission electron microscopy, N2 adsorption/desorption, scanning electron microscopy, magic-angle spinning nuclear magnetic resonance, and elemental analysis. The results revealed that the micropores of SBA-15 were preferentially blocked, and APTMS increasingly occupied the mesopores with increasing amine loading. The CO2-adsorption performance of the adsorbents was measured by thermogravimetric analysis under dry conditions. Both synthesis methods achieved high amine immobilization efficiency (78.3–92.2%), as estimated from the amount of silane coupling agents used in the synthesis and that immobilized on the support. The adsorbents prepared by the two methods adsorbed similar amounts of CO2 of approximately 0.5 mmol g− 1 in 400 ppm CO2 and ~ 1.0 mmol g− 1 in 5 vol% CO2. The adsorption amounts attained in this study are comparable to those of previously reported silane-coupling-agent-modified adsorbents that were prepared with more silane. In contrast, the adsorption rate of the samples was affected by the synthesis method, even with similar amine loadings. Nonetheless, the results revealed that even with a low amount of the silane coupling agent, high-performance amine-grafted CO2 adsorbents could be synthesized.

Effect of Composite Interface Enhancer on the Cementation Strength of Shale Formation–Cement Ring Interface

The cement strength between the cement and the formation is a key factor in determining the cementation sealing capacity. In the shale formation, due to the organic matter content, the cementing quality between the formation and the cement ring is poor, which affects the quality of cementing. It is easy to cause problems such as annulus pressure. To improve the quality of cementing, this paper investigates the effect of amino silane coupling agents, vinyl silane coupling agents and aluminium–zirconate coupling agents on the interface cementation of rock and cement under different conditions. Meanwhile, the effects of different coupling agent compounding on improving the cementation interface cement strength under different temperature and concentration conditions were investigated. This led to the development of a composite interface enhancer. The composite interface enhancer can improve the bond strength between cement and rock by 189.22%. A preflush fluid system was developed to effectively improve the cementation strength of mud shale formations, and its performance was evaluated. The density of the preflush fluid system is 1.15 g·cm−3, and it has good rheology, settlement stability, and filtration loss. In addition, it improves the cementing interface cementing strength between the cement and shale formation.

Interaction of silica with polystyrene: mechanical properties, polymer/filler adhesion and failure behavior

Composites of polystyrene with different loading of silica were prepared by melt mixing in a Brabender Plasticorder at a rotor speed of 60 rpm. The mechanical properties of the composites such as tensile behavior, impact strength, and flexural properties were studied as a function of filler loading. The tensile moduli of the composites increased with silica content. To improve adhesion between the filler and the matrix, an amino silane coupling agent was used. The composites with coupling agents showed enhanced mechanical properties. Thermal properties were measured using differential scanning calorimetry (DSC), thermogravimetry (TGA) and flammability tests. Composites with 15 wt.% and 0.5 wt.% coupling agent showed optimum properties. Scanning electron microscopy (SEM) studies of the tensile fractured samples revealed the extent of filler dispersion and filler/matrix interaction. Finally, experimental results were compared with theoretical predictions.

Non-polyamide nanofiltration membranes with low MWCO prepared by combining the catechol-amine chemistry and the chemistry of amino-silane coupling agents

The present work provides an efficient strategy to prepare mussel-inspired nanofiltration membranes with lower MWCO, via combining the catechol-amine chemistry and the chemistry of amino-silane coupling agents. The membranes were synthesized by stepwise depositing tannic acid (TA) and pre-hydrolyzed 3-aminopropyltriethoxysilane (APTES) on the PSF support. TA adsorbed on the polysulfone (PSF) support via hydrogen bonding. The pre-hydrolyzed APTES self-polymerized and reacted with TA, forming a crosslinked network through the Michael addition/Schiff base reactions. The membrane performance was tailored by controlling the hydrolysis degree of APTES. At optimal conditions, the APTES-TA/PSF membrane with MWCO of 200 Da and water permeance of 11 Lm−2h−1bar−1 was fabricated. The salt rejections toward Na2SO4 and NaCl were around 90% and 20% respectively. The continuous prolonged filtration showed the membrane had good filtration stability. Compared with previously reported mussel-inspired and polyphenol membranes, the present membrane had a much lower MWCO and higher permeance. The membrane can efficiently remove typical pharmaceuticals with molecular weight from 200 to 400 Da, indicating this type of membrane has promising prospects in trace-organic contaminated wastewater treatment.

A Study of the Degradation Mechanism of Ladder-like Polyhedral Oligomeric Silsesquioxane via Fourier Transform Infrared Spectroscopy

As a result of global warming, fire outbreaks are becoming a common occurrence. There is, therefore, the need for an effective, low-cost and environmentally friendly fire-retardant material. Amine-terminated polyhedral oligomeric silsesquioxane, ATL-POSS, is a low-cost, water-soluble, fire-retardant material based on aminosilane coupling agents. Because of its solubility in water, it can serve as a general-purpose fire retardant. The ATL-POSS nanoparticles reported in this paper have high char retentions of about 75 and 54% in nitrogen and air atmospheres, respectively. Differential scanning calorimetry (DSC) was used to determine the phase transition temperatures. It was shown that ATL-POSS is an amorphous material. The thermal stability and rate of decomposition of POSS was determined by using thermogravimetric analysis (TGA). The TGA derivative curves (DTA) show that the degradation of ladder-like POSS occurred in multiple stages and that the rate of degradation is affected by the heating rate. The mechanism of decomposition of ATL-POSS was determined by using Fourier transform infrared spectroscopy, FTIR. The FTIR technique was chosen for this study because of its accessibility and ability to distinguish ladder-like POSS from the cage-type POSS structures. The FTIR spectra showed that the -Si-O-Si- cyclic structure was the predominant structure of POSS. By analyzing the FTIR spectra of the thermally treated POSS residues, obtained at the specified test temperatures, the detailed degradation mechanism of POSS was inferred. It was shown that the terminal silanol group was degraded at test temperatures below 400 °C. Silica was shown to be the final product of the pyrolysis of POSS. The presence of the FTIR transmission peaks at 1000 and 1100 cm−1, due to asymmetric vertical and horizontal stretching vibrations of the Si-O-Si, respectively, was the key evidence used to infer the ladder-like structure of POSS.

Preparation of ambient-dried multifunctional cellulose aerogel by freeze-linking technique

Ambient drying is currently the cheapest and most efficient way to prepare aerogels, but it is invisible for the preparation of cellulose aerogels. In this paper, we describe a method of preparing cellulose aerogels that can be dried under atmospheric pressure by freeze-linking technique. The amino silane coupling agent forms an amino-rich polymer layer on the bacterial cellulose surface during the freezing process. And, the cross-linked network constructed by Schiff base reaction can strengthen the fiber skeleton in the process of solvent exchange. Due to the double cross-linked network structures, the cellulose ethanol gel can be dried directly under atmospheric pressure at 60 °C and the volume shrinkage can be as low as 3.3 %±1.4 %. In the process of solvent exchange, the loss of some polysiloxane causes defects in the aerogel, which not only reduces its thermal conductivity but also increases its specific surface area. And the water resistance, thermal performance, and dye adsorption performance of the aerogel are also significantly improved. This study provides a low-cost and high-efficiency solution for the manufacture of cellulose aerogels and promotes their wide applications.

The Synergistic Effects of Aminosilane Coupling Agent on the Adhesion Performance of Silane Primer for Silicone Resin Thermal Protection Coating.

As a bridge between the coating and the substrate, the primer has a direct impact on the adhesion performance of silicone resin thermal protection coating. In this paper, the synergistic effects of an aminosilane coupling agent on the adhesion performance of silane primer were investigated. The results show that silane primer containing N-aminoethyl-3-aminopropylmethyl-dimethoxysilane (HD-103) formed a continuous and uniform film on the surface of the substrate. Two amino groups of HD-103 were conducive to moderate and uniform hydrolysis of the silane primer system, and the introduction of dimethoxy groups was more conducive to the improvement of interfacial layer density and the formation of the planar surface structure, thus enhancing the bond strength at the interface. When the content was 13 wt%, it exhibited excellent synergistic effects on adhesive properties, and the adhesive strength reached 1.53 MPa. The possible morphology and composition of the silane primer layer were investigated by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). A thermogravimetric infrared spectrometer (TGA-IR) was used to analyze the thermal decomposition of the silane primer layer. The results showed that the alkoxy groups in the silane primer were first hydrolyzed to form Si-OH, and then the dehydration and condensation reactions between Si-OH and the substrate formed a firm network structure.

A functional bimodal mesoporous silica nanoparticle with redox/cellulase dual-responsive gatekeepers for controlled release of fungicide

Integrating toxic fungicide into a functional stimuli-responsive nanosystem can effectively improve the fungus control specificity and reduce the effect on non-target organisms. We report here a redox and cellulase dual-responsive multifunctional nanoparticle based on bimodal mesoporous silica (BMMs) to deliver prochloraz (Pro) for the smart management of wilt disease (Pro-AC-SS-BMMs, known as P-ASB). The surface of the nanocarrier was modified with an aminosilane coupling agent, and Pro was encapsulated by physical adsorption using 2,2′-dithiodiacetic acid as a smart bridge and disulfide (SS) cross-linked aminocellulose (AC) as gatekeepers. P-ASB nanoparticles (NPs) had a spherical structure, and the size was 531.2 ± 4.9 nm. The loading rate of Pro was 28.5%, and the NPs possessed excellent redox/cellulase dual-responsive release characteristics in the presence of glutathione (GSH) and cellulase. The nanocarrier could effectively protect Pro against photodegradation and had better foliar wettability than the Pro technical. Fluorescence tracer results showed that the nanocarriers were taken up and activated by the mycelium. P-ASB NPs had better control efficacy against Rhizoctonia solani and had no significant toxicity to cells and bacteria. This study provides a new strategy for enhancing the environmental protection and promoting the development of green agriculture.

Ni and Ce Grafted Ordered Mesoporous Silica KIT-6 for CO2 Adsorption

In this study, the Ni/KIT-6 and Ce/KIT-6 materials were prepared through the impregnation method and then amino-functionalized materials were obtained by the grafting of an amino-silane coupling agent 3-aminopropyl triethoxysilane (APTES). The samples were characterized by thermogravimetric analysis (TGA-DTA), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction, scanning electron microscopy (SEM) and nitrogen adsorption at 77 K. The study of CO2 adsorption–desorption on prepared materials was investigated using thermogravimetric analysis (TGA-DTA) coupled with mass spectrometry (MS). The influence of metal oxides on the performance of CO2 adsorption on functionalized mesoporous silica was presented. The results showed that doping the molecular sieve with cerium oxide can significantly increase the adsorption capacity of the amino-functionalized KIT-6. As the CO2 adsorbents were prepared by functionalization through grafting with APTES, the amount of amine loading is one of the important factors which improves CO2 adsorption capacity. Additionally, CO2 adsorption performance depends on the textural properties and the temperature used for the adsorption process. The maximum adsorption capacity of Ce/KIT-6 Sil is 3.66 mmol/g, which is 2.4 times higher than Ni/KIT-6 Sil. After the nine cycles of cyclic CO2 adsorption/desorption, the Ce/KIT-6 Sil still had higher adsorption capacities, indicating their good cyclical stability.

Reinforcement of boron–nitrogen coordinated polyurethane elastomers with silica nanoparticles

Polyurethane elastomer nanocomposites are strategically important due to their indispensable applications in daily life and high-tech fields. Herein, a series of nanocomposites with extraordinary strength, toughness and energy dissipation are reported, which are enabled by multiple dynamic moieties including dynamic boronic ester covalent bonds, boron-nitrogen coordination bonds in the matrix and on the interface. The surface-modified silica nanoparticles with amino-silane coupling agent (D-SiO2) were added to the polyurethane matrix that contains boron-nitrogen coordination. The presence of interfacial coordination significantly improves the dispersion of D-SiO2 and enhances the interface interaction of polyurethane composites (SPU/D-SiO2), which is evidenced by scanning electron microscopy, transmission electron microscopy and rheological investigation. Through mechanical experiment analysis, these modified polyurethane composites exhibit high tensile strength and toughness. The tensile strength of SPU/10D-SiO2 increases to 19.5 ± 0.2 MPa and its tensile toughness achieves 216.9 MJ/m3, which is 35% of increase as compared with the pristine SPU that had a record-high toughness. In addition, the coordination bonds in the matrix and interface in the composites provide versatile and efficient energy dissipation during the tensile process. This work offers a facile method to improve the mechanical robustness of the newly developed supramolecular polyurethane elastomers.

Laccase Cross-Linked Ultraporous Aluminas for Sustainable Biodegradation of Remazol Brilliant Blue R

Over the past few decades, enzyme-based green and sustainable chemistry has attracted extensive research attention, which provides a promising alternative to the conventional treatment methods of recalcitrant micropollutants. However, enzyme denaturation and stability loss remain critical challenges for its potential applications in industrial wastewater treatment. In this study, laccase from Trametes versicolor (laccase T.) was cross-linked immobilized by ultraporous alumina (UPA) for the sustainable biodegradation of Remazol Brilliant Blue R (RBBR). Through sequential use of an aminosilane coupling agent (3-aminopropyl)triethoxysilane (APTES) and bifunctional cross-linker glutaraldehyde (GA), the synthesized biocatalysts showed better immobilization performances (about 4-fold to physical adsorption). The GA concentration considerably affected the laccase T. cross-linking degree, while the GA post-treatment protocol showed the highest laccase T. immobilization yield with lower activity recovery. Moreover, the biocatalyst stabilities including pH stability, thermal stability, storage stability, and reusability were also studied. Tolerance to broader pH and temperature ranges, better storage stability, good reusability of laccase T. cross-linked UPA(γ) biocatalysts, and their continuous RBRR biodegradation efficiency highlight the potentials of enzyme-based inorganic materials in industrial wastewater treatment, which can broaden our understanding of their practical applications in environmental fields.

Improvement of mechanical and wear resistance property by varying glass fiber contents and amino-silicate coupling agents on polyamide 612 composites

Among the polyamide series polymer materials, PA612 has excellent mechanical properties and low moisture absorption characteristics. This work studied the effect of coupling agent addition on the crystallization behavior, adhesive wear, mechanical, thermal, and morphological attributes of glass fiber (GF) reinforced PA612 composites. Amino-silane was applied as a coupling agent to enhance the interfacial adhesion between glass fiber and the PA612 matrix. The loading level of the coupling agent was changed to 0.5, 1.0, and 2.0wt%, while the GF loading level in the composite material was 10, 15, 20, and 30wt%. The composite materials were analyzed via X-ray diffraction, tribological characterization, and adhesion wear test. The mechanical, rheological, and thermal properties were also investigated. In addition, scanning electron microscopy (SEM) analysis was used to study the analytical samples’ wear and fracture surfaces. Test results unveiled that adding 1.0wt% amino-silane coupling agent upgraded the fiber-matrix adhesion, mechanical properties (tensile strength:136 MPa), and corresponding wear resistance of GF reinforced PA612-based composites. Furthermore, it is compatible with pure PA612 substrates and has similar processing rheological behavior. These results reveal that the compiled PA612 matrix is highly viable for tribological applications comprising automotive parts, bearings, and bearing materials for space applications.

Kinetic, Isotherm, and Equilibrium Investigation of Cr(VI) Ion Adsorption on Amine-Functionalized Porous Silica Beads.

The hexavalent chromium (Cr(VI)) ion adsorption properties were conferred to porous silica beads by introducing alkylamine chains through functionalization with an aminosilane coupling agent, [3-(2-aminoethylamino)propyl]triethoxysilane (AEAPTES), or with an epoxysilane coupling agent, (3-glycidyloxypropyl)triethoxysilane (GOPTES), and polyfunctional amine compounds or poly-ethylenimines (PEIs). The presence of amino groups on the silica beads was confirmed by XPS and the amount of amino groups increased to 0.270 mmol/g by increasing the AEAPTES concentration and/or reaction time. The adsorption capacity of the silica beads functionalized with AEAPTES was the maximum at the initial pH value of 3.0 and the initial adsorption rate increased with an increase in the temperature. The adsorption capacity increased with an increase in the amount of amino groups at pH 3.0 and 30 °C. The adsorption behavior obeyed the pseudo-second order kinetic model and was well expressed by the Langmuir isotherm. These results support that Cr(VI) ion adsorption is accomplished through the electrostatic interaction between protonated amino groups and HCrO4− ions. In addition, the adsorption capacity further increased to 0.192–0.320 mmol/g by treating the GOPTES-treated silica beads with triethylenetetramine, pentaethylenehexamine, or PEI. These empirical, equilibria, and kinetic aspects obtained in this study support that the porous silica-based adsorbents prepared in this study can be applied to the removal of Cr(VI) ions.

Synthesis of substrate-bound seaweed-like Au nanowires with amino silane coupling agents.

A seedless method has been developed to synthesize seaweed-like Au nanowires on a Au substrate. The amino silane coupling agent 3-aminopropyltriethoxysilane was employed to form the active surfaces that facilitate the one dimensional growth. The growth mechanism and controlling parameters were investigated. Furthermore, the compatibility of this synthesis with a colloidal Au substrate was also demonstrated.

Layer-by-layer assembly of nanofilms from colloidally stable amine-functionalized silica nanoparticles

The assembly of uniform thin films with functional silica nanoparticles (FSNPs) by the layer-by-layer (LbL) technique has been studied to provide rough, robust, and functional surfaces. Initially, monodisperse silica nanoparticles (SNPs) have been synthesized by the reverse microemulsion method. Then SNPs have been functionalized using amino silane coupling agents with various chain lengths and amine positions such as (3-aminopropyl)trimethoxy silane (APS), N-[3-(trimethoxysilyl)propyl]-N,N,N-trimethylammonium chloride (NPC), N -(6-aminohexyl)aminopropyltrimethoxy silane (AHAPS), and 3-aminopropyl(dimethyl)ethoxy silane (APDMES). The amine-functionalized silica nanoparticles have been characterized using zeta potential, Fourier Transform-Infrared Spectroscopy (FT-IR), and 1 H Nuclear Magnetic Resonance (NMR) spectroscopy to prove the existence of amine groups on the silica surface. Scanning electron microscopy (SEM) images have revealed that the LbL assembled thin film coatings of FSNPs are uniform and monodisperse. The thickness measurements of the coatings have been conducted by spectroscopic ellipsometry. Water contact angle measurements were performed to analyze the alteration of surface features with functional groups. The roughness, topography, and elastic modulus of the assembled thin-film coatings were probed by atomic force microscopy (AFM). The dispersion of AHAPS-FSNPs has indicated superior colloidal stability than other FSNPs because of their secondary amines creating steric hindrance. Moreover, AHAPS-FSNPs film exhibited the lowest coating thickness and the highest elastic modulus comparing with the other FSNPS because of their crosslinking and hydrogen-bonding ability. Briefly, in this work, LbL assembly of the amine FSNPs was established by an extensive investigation to form rough and functional surfaces for many demanding applications.

Fabrication of a highly hard yet tough epoxy nanocomposite coating by incorporating graphene oxide nanosheets dually modified with amino silane coupling agent and hyperbranched polyester-amide

This study aims to promote the epoxy systems' mechanical attributes (especially toughness) using surface-treated graphene oxide nanosheets. To this end, the graphene oxide nanoplatelets were synthesized and then surface-modified. 3-amino propyl triethoxy silane (APTES) and hyperbranched polyester amide (HBP) were employed via a serial approach. The results of different characterizing techniques (FTIR, TGA, XRD, Raman, and FE-SEM) approved the leading role of dual modification in expanding the inter-layer distance of nanoplatelets and significantly improving the filler dispersion within organic media. All unmodified and variously modified nanosheets were introduced into the epoxy at three loading levels (0.25, 0.5, and 1 wt%). While almost all modified nanoparticles could considerably enhance the hardness and toughness, the highest enhancement (2.6 times in toughness and 2.28 times in micro-hardness) was achieved with 1 wt% graphene oxide sequentially treated with APTES and HBP. Simultaneous promotion of hardness and toughness, which usually have an inverse relationship, was a highly desirable achievement. Our structural studies, utilizing the DMTA technique, revealed that such promotion was indebted to the simultaneous reinforcement in the physical (uniform filler distribution) and chemical (increased crosslinking density without any Tg elevation) aspects of the resultant network.

Enhanced interfacial and mechanical properties of basalt fiber reinforced poly(aryl ether nitrile ketone) composites by amino-silane coupling agents

Basalt fiber (BF) reinforced heat-resistant thermoplastic engineering plastic composites exhibit excellent toughness, strength, corrosion resistance, and high- and low-temperature resistance. However, the BF and resin exhibit poor interfacial compatibility resulting in low interfacial strength. Here, mono-, di- and tri-amino silane coupling agents (3-aminopropyltrimethoxysilane, SATMS; N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, DATMS and (3-trimethoxysilylpropyl)-diethylenetriamine, TATMS) were used to treat BF, and composites were then prepared using the modified BF and high-performance thermoplastic poly(phthalazinone ether nitrile ketone) (PPENK). The chemical structures, surface morphologies, roughness and hydrophilicity of the modified BF surface were characterized. In addition, the flexural strength, tensile strength and interlaminar shear strength of BF-DATMS/PPENK composite increased to 1127 MPa, 633 MPa and 55 MPa, which are 18%, 30% and 25% higher than the desized-BF/PPENK, respectively. And the BF-DATMS/PPENK composite exhibited a glass transition temperature (Tg) of 293 °C higher than those of PPENK (280 °C) and desized-BF/PPENK (285 °C). Results indicated that the interfacial adhesion between BF and PPENK were improved by the amino-silane modified BF, which in turn enhanced the mechanical properties of the corresponding BF/PPENK composites.

Coupled experimental and simulative investigation of the influence of polymer moisture content on the strength of amino-silane-mediated aluminum polyamide 6 joints

Amino-silane coupling agents are used to improve adhesion to polyamide-based composites. This paper aims to study the influence of polyamide 6 moisture content on the interfacial strength between the polyamide and amino-silane-coated aluminum. A coupled experimental and simulative approach is applied that enables the interfacial strength to be taken separately from the moisture-dependent mechanical behavior of polyamide 6. Lap joints of polyamide 6 and aluminum, functionalized by 3-(2-aminoethylamino)propyl trimethoxy silane, are tested at three different polyamide moisture conditions. Afterwards, numerical simulations of the lap shear experiments are carried out to identify the parameters for a mechanical model of the interface. Subsequently, the dependence of polymer's properties on the moisture content is investigated by different sets of parameters of an applied inelastic material model. Finally, an analysis of the interfacial parameters proves and characterizes the dependence of the joint strength on polyamide moisture content. It is found that the lower the moisture content of the polyamide, the higher the interfacial strength.