Bonding between epoxidized natural rubber and clay in presence of silane coupling agent

Based on the results of bound‐rubber determination, Monsanto rheometric studies, solvent swelling, measurement of physical properties, and infrared spectroscopic studies, it is revealed that epoxidized natural rubber (ENR) and hard clay interact chemically to form Si–O–C bond during high‐temperature (180°C) molding. It is also observed that addition of the silane coupling agent N‐3‐(N‐vinyl benzyl amino)ethyl‐γ‐amino propyl trimethoxy silane monohydrogen chloride enhances the extent of the chemical interaction with the formation of coupling bonds of Si–O–Si type between clay and the coupling agent and C–N bonds between ENR and the coupling agent. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 72: 1895–1903, 1999     

Bonding between precipitated silica and epoxidized natural rubber in the presence of silane coupling agent

Results of Monsanto rheometic studies and measurements of physical properties reveal that precipitated silica interacts chemically with epoxidized natural rubber (ENR) during high temperature (180°C) molding and the extent of chemical interaction increases in the presence of silane coupling agent, namely N‐3(N‐vinyl benzyl amino) ethyl‐γ‐amino propyl trimethoxy silane monohydrogen chloride. Fourier transform infrared spectroscopic studies show that silica is bonded to ENR through formation of Si—O—C bond, whereas in the presence of silane coupling agent, silica is bonded to the coupling agent through Si—O—Si bond, and ENR is bonded to the coupling agent through C—N—C bond formation. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 389–398, 1999     

Copper corrosion protection of various silane-modified poly(vinyl imidazole) (1)s

Vinyl imidazole (VI) was copolymerized with four silane coupling agents, allyl trimethoxysilane (ATS), γ-methacryloxypropyl trimethoxysilane (MPS), 3(N-styrylmethoxyl-2-amino-ethylamino)propyltrimethoxysilane hydrochloride (STS), and vinyl trimethoxysilane (VTS), in benzene at 68°C using azobisisobutyronitrile (AIBN) as an initiator. Fourier transform infrared reflection and absorption spectroscopy (FTIR-RAS) and scanning electron microscopy (SEM) were applied to the study of the corrosion protection on copper by various silane-modified poly(vinyl imidazole)(1)s [PVI(1)]s. Four silane-modified PVI(1)s proved to be good corrosion inhibitors in humid conditions. However, the corrosion protection capability at an elevated temperature of silane-modified PVI(1)s depended on their thermal stability. Poly(VI-co-VTS) showed the best corrosion protection capability at elevated temperature due to its highest thermal stability. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 2585–2595, 1997     

Effects of chemical surface pretreatment on tensile properties of a single glass fiber and the glass fiber reinforced epoxy composite

The aim of this article is to determine the effect of surface pretreatments, prior to the silanization, on the structure and tensile properties of the glass fibers and their epoxy composites. Commercial glass fibers were washed with acetone to remove the soluble portion of sizing, calcinated for the removal of organic matter, activated for surface silanol regeneration, and silanizated with glycidoxypropyltrimethoxysilane (GPS). Tensile test was carried out. The morphology of pretreated glass fibers and the fracture surfaces of the epoxy composites were observed with a scanning electron microscope (SEM). The results revealed that both apparent modulus and strength of a single glass fiber and the glass fiber/epoxy resin composites strongly depend on the fiber surface pretreatments. The acetone treatment did not change appreciably the composition and tensile properties of glass fibers, but there was a weak interface between fibers and matrix. In calcinated and acid activated fibers, the two competitive effects was observed: (1) degradation of the fibers themselves and (2) improved interfacial adhesion between the glass fibers and the epoxy matrix, once the samples was silanizated. The ATR‐FTIR results show that the surface content of Si OH increases as reflected by the increasing of the Si O band, resulting in an interaction between silane coupling agent and glass fiber. POLYM. COMPOS., 91–100, 2016. © 2014 Society of Plastics Engineers     

Room Temperature Curing Epoxy Adhesives for Elevated Temperature Service. Part III. The Effect of Silane Coupling Agents

The effect of silane coupling agents incorporated into the bulk of previously-developed room-temperature-curing epoxy adhesives^8,9,10 was studied. The physical and mechanical properties of corresponding aluminum bonded joints were characterized in ambient and humid-hot environments. Experimental results have demonstrated significant advantages of silane addition to the performance of these epoxy adhesives, especially under exposure to humid atmosphere. Thermal analysis of the polymerization processes, taking place during curing of the various low-temperature-curing formulations containing silane coupling agents, indicates that curing is not complete after seven days at room temperature, showing an exotherm at 80-100°C and a residual small one at 120°C. The basic formulation, comprising a tetra- and trifunctional epoxy resin blend and a multifunctional amine and ATBN cross-linking mixture, developed a three-phase matrix-rubber microstructure when the silane was added to the system.     

Mechanical and interfacial properties of phenolic composites reinforced with treated cellulose fibers

Cellulose fiber‐reinforced phenolic composites were prepared and characterized by mechanical tests and morphological analysis in this study. First, preparation of the phenolic matrix was optimized using an experimental design. The variables studied were curing temperature and time. The responses measured were strength, elongation, modulus, and strain energy density, in tensile and flexural tests. After fixing the optimal curing conditions of the matrix at 75°C and 2.75 h, the effect of a latest drying stage was studied. Strengths in tensile and flexural tests of the matrix after the incorporation of the drying stage were 156 and 189% of the strengths of the undried matrix, and elastic moduli were three‐fold. Finally, cellulose fibers were incorporated as reinforcement. Alkali treatment of the fibers (1 and 5% NaOH), employment of silanes as coupling agents [(3‐aminopropyl) trimethoxysilane (APS) and 3‐(2‐aminoethylamino) propyltrimethoxysilane (AAPS)], and combined treatments alkali‐silane were tested. The AAPS silane treated cellulose fiber‐reinforced phenolic composite was the material with the best mechanical performance and adhesion fiber–matrix. The most significant improvements obtained with the AAPS silane treatment of the fibers were 25, 52, and 110% for tensile strength, elongation, and SED, respectively, in relation to the unreinforced material properties. POLYM. ENG. SCI., 54:2228–2238, 2014. © 2013 Society of Plastics Engineers     

Preparation and epoxy curing of novel dicyclopentadiene‐derived Mannich amines

Phenol/dicyclopentadiene (DCPD) adducts were prepared from the BF₃‐catalyzed reaction of p‐nonylphenol and dicyclopentadiene at molar ratios of 2 : 1 and 3 : 2. The phenol‐terminating adducts were consequently reacted with diethylenetriamine and formaldehyde using Mannich reaction conditions. These products containing phenol, amine and tricyclodecane functionalities in the same molecule can be used as epoxy curing agents. The diethylenetriamine was add to the phenol via Mannich reaction at approximately 50% theoretical equivalent. The multiple N H groups in amines and the O H groups in phenols provide crosslinking sites for epoxy resins. The cured epoxy resins show improvement in tensile strength and elongation in comparison with those cured by the poly(oxypropylene) diamine (400 molecular weight) or diethylenetriamine. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 2129–2139, 1999     

Chemical modification of LDPE film

Low‐density polyethylene (LDPE) film was chemically modified by chromic acid treatment to generate polar groups on the surface. The film samples were etched by chromic acid with variation of temperature at a constant time (30 min) and variation of time at a constant temperature (room temperature = 26°C). The variation of weight and thickness of the film samples before and after etching was measured. The surface morphology of the etched films was studied by Scanning Electron Microscopy (SEM). IR and XPS analysis revealed the introduction of polar groups like  COOH, 〉CO,  SO₃H on the etched LDPE film surface, which exhibited improved printability. Etching also enhanced adhesion with epoxy resin. The mechanical properties of the laminates of the two specimens of the same film sample with epoxy resin were also measured. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 1041–1048, 1999     

Effect of Silane Coupling Agents on Adhesion of Polybutadiene to Glass

The chosen silane coupling agents consist of a polybutadiene skeleton with  Si(CH₃)₂OCH₃ or  Si(OCH₃)₃ pendent groups hydrolyzable on the glass surface. Their number, and therefore the amount of potential bonds, can be varied. These modified polybutadiene polymers act as primer compatible with the polybutadiene coating to be deposited. The subsequent cross-linking of the double bonds of the silane primed surface with polybutadiene is initiated by benzoyl peroxide, creating chemical bonds between the solid support and its coating. The strength of the adhesion of polybutadiene to glass is measured by the 180° peel test and the values are compared with a non-modified glass surface.     

Advanced anticorrosion coatings prepared from polybenzoxazine/siloxane-containing epoxy resin

In this study, a new type of coating comprising benzoxazine and siloxane-containing epoxy (SiEP) resin was prepared by the thermal curing method. The FTIR (Fourier transform infrared) analysis not only confirmed the complete reaction between polybenzoxaine and SiEP resin after heat curing, but also found the hydrogen-bonding interactions between them. The addition of SiEP resin significantly enhanced the hydrophobicity and adhesion ability of the coating and greatly improved the water contact angles of the blend coatings (>108°), compared to that of the pristine PBa coating, which attributed to the introduction of a Si O Si network structure in the matrix. In addition, the corrosion resistance of the coating was tested though a series of electrochemical experiment. According to the results, the corrosion current values of the blend coatings decreased by about four orders of magnitude compared to that of the pristine carbon steel, and the corrosion protection efficiency of the blend coatings were >99%, indicating good application prospect of these blend coatings.     

Synthesis,characterization and anticorrosion property of olive leaves extract-titanium nanoparticles composite

Ethanolic extracts of olive leaves (OLE) in the presence of TiCl₄ solution was used to form OLE – Ti nanoparticles composite (OLE-Nano). The particle size of Ti nanoparticles in the composite was determined using particle sizer and the nanoparticles were characterized using UV–vis, FTIR, SEM/EDAX and XRD techniques. Results show that the particles were around 70–74 nm in size and show maximum absorption around 420 nm. Prominent FTIR peaks correspond to C=C, N–H, O–H and C=O functionalities. XRD spectrum shows four distinctive diffraction peaks at 27.42°, 36.07°, 41.23°, and 54.30° corresponding to lattice plane value indexed at (101), (104), (200) and (211) planes of face centered cubic (FCC). The anticorrosion property of the OLE-Nano for mild steel in 1 M HCl at 30–60 °C was assessed using weight loss and electrochemical techniques complemented by surface analysis of the corroded steel specimen in the absence and presence of OLE – Nano with SEM and AFM. Results obtained show that OLE inhibited the acid corrosion of mild steel and the inhibition performance was enhanced in the presence of Ti nanoparticles. The corrosion inhibition effect was found to be concentration and temperature dependent. The inhibition efficiency of the OLE and OLE-Nano were 83.5 and 94.3% respectively at 30 °C but decreased to 51.7 and 85.4% at 60 °C respectively. The OLE-Nano adsorbed on mild steel surface by physical adsorption mechanism as predicted by Langmuir adsorption isotherm model. Potentiodynamic polarization results show that OLE-Nano behaves as mixed type inhibitor.     

Relation between hydrophilicity and cell culturing on polystyrene Petri dish modified by ion‐assisted reaction

Polystyrene Petri dishes were modified by an ion‐assisted reaction to supply a suitable surface for culturing cells. Wettability was measured by a contact anglometer after surface modification of polystyrene. Contact angles of water on the polystyrene were not reduced much by Ar⁺ ion irradiation only, but dropped rapidly to a minimum of 19°, when polystyrene surface was modified by Ar⁺ ion irradiation with flowing oxygen gas. X‐ray photoelectron spectroscopy analyses showed that hydrophilic groups were formed on the surface of polystyrene by a chemical reaction between unstable chains induced by the ion irradiation and the blown oxygen gas. Newly formed hydrophilic groups were identified as C O,  (CO) and  (CO) O bonds. The influence of the ion beam modification in growth of the rat pheochromocytoma cells was investigated. The results showed exclusively preferential cell growth in the polystyrene Petri dish that was treated by the ion‐assisted reaction. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 41–46, 1999     

Plasma and Silane Surface Modification of SiC/Si: Adhesion and Durability for the Epoxy–SiC System

Gaseous plasma pretreatments and surface derivatization using silane coupling agents (SCA) have been used to enhance the adhesive bonding of an epoxy to SiC-coated Si wafers (SiC/Si). The surface modification approaches included 1) an SCA treatment using 3-aminopropyltriethoxysilane (APS) or 3-glycidoxypropyltrimethoxysilane (GPS) and 2) an oxygen plasma pretreatment followed by a silane treatment. Durability was evaluated by immersing epoxy-coated SiC/Si samples in aqueous solutions at various pHs at 60°C for selected times. Adhesion durability for the epoxy-coated SiC/Si systems was qualitatively evaluated by visual inspection to identify debonding and quantitatively evaluated with a probe test to determine the critical strain energy release rate, G _c . Durability via either test approach varied as a function of surface treatment in this manner: oxygen plasma treatment plus silane modification > silane treated > no treatment. X-ray photoelectron spectroscopic characterization of surfaces was carried out following the surface treatments and after complete adhesion failure in the durability tests. The XPS results suggested that improved performance was due to plasma cleaning and modification of the substrate surface, promotion of silane surface interaction, and the formation of a thicker oxide layer.     

Effect of coupling agent and filler particle size on melt rheology of polymer-bonded Nd-Fe-B magnets

The effect of coupling agents and filler particle size on melt rheology of poly(phenylene sulfide)-bonded neodymium-iron-boron (Nd-Fe-B) alloy magnets was studied with oscillatory flow experiments to accelerate efforts to optimize their processing. The minimum viscosity of the polymer-bonded magnets near 290°C was obtained with Nd Fe B fillers (106–150 particle size range) that were coupled with a silane coupling agent. All the samples tested followed power-law fluid flow behavior. Morphological and dynamic mechanical analysis of the samples showed that the beneficial function of the coupling agent may be ascribed to enhanced wetting of the magnetic Nd Fe B powders by the polymer, improving the processability of the polymer bonded magnets.     

Preparation and anticorrosive properties of hybrid coatings based on epoxy‐silica hybrid materials

A series of sol‐gel derived organic–inorganic hybrid coatings consisting of organic epoxy resin and inorganic silica were successfully synthesized through sol‐gel approach by using 3‐glycidoxypropyl‐trimethoxysilane as coupling agent. Transparent organic–inorganic hybrid sol‐gel coatings with different contents of silica were always achieved. The hybrid sol‐gel coatings with low silica loading on cold‐rolled steel coupons were found much superior improvement in anticorrosion efficiently. The as‐synthesized hybrid sol‐gel materials were characterized by Fourier‐transformation infrared spectroscopy, ²⁹Si‐nuclear magnetic resonance spectroscopy and transmission electron microscopy. Effects of the material composition of epoxy resins along with hybrid materials on the thermal stability, Viscoelasticity properties and surface morphology were also studied, respectively. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Optimization of amphiphobic structural surface thickness in relation to its functionality on stainless steel plates

Fluorine‐based amphiphobic coatings have been widely used in commercial textiles to provide water‐ and oil‐repelling abilities. However, few reports from the literature survey have discussed the surface structural effects of the coated substrate on amphiphobicity. In this research, various thickness amphiphobic coatings based on mixed epoxy, tetraethylorthosilicate, and a particular alkoxysilane with fluorinated side chains (F‐silane) were deposited on Grade 420 stainless steel plates. Film amphiphobicity is characterized by measuring the water and oil contact angles of the coating. Film morphology is examined using atomic force microscopy. The deposited films free of F‐silane are thinner than 150 nm. The films become thick at high F‐silane volume percentage with the surface cavities, ridges, and granules being masked out. On the addition of F‐silane, the water contact angle of the deposited films increases up to 105° and then reaches a plateau of ～ 107° with increasing F‐silane. In contrast, the oil contact angle increases up to 60° at first and then slowly declines with the F‐silane concentration. The total drop of oil contact angle by ～ 20° was attributed to the masking out of surface features on film thickening. This indicates that the surface oleophobicity depends on surface structures. Therefore, improving surface amphiphobicity correlates with creating more refined multiscale surface structures during the industrial manufacturing process of steel plate, prior to surface modification by F‐silane. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41003.     

Microstructure and thermal properties of silyl-terminated polycaprolactone–polysiloxane modified epoxy resin composites

With a direct nucleophilic addition between  OH groups of polydiol and  NCO of a silane, a blend of silyl-terminated polycaprolactone PCL-Si and silyl-terminated polydimethylsiloxane PDMS-Si oligomer, PCS-2Si, were firstly prepared, and then blended with a commercial epoxy resin (diglycidyl ether of bisphenol-A, DGEBA) to form a ternary composite. The formed ternary composites of different content of DGEBA were cured using a polyamidoamine as a curing agent and a sol–gel process at ambient temperature. The microstructures and properties of the cured composites were investigated by SEM, TGA, and energy dispersive spectroscopy. The results showed the compatibility between DGEBA and PDMS increased with increasing content of PCS-2Si, but higher content of PCS-2Si resulted in a slight enrichment of silicon in the surface of the cured film. TGA showed that incorporating PCS-2Si into epoxy resin altered the composites' thermal stability and degradation characteristics. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Interfacial adhesion and water resistance of stainless steel–polyolefin improved by functionalized silane

The adhesion strength and water resistance of stainless steel and adhesive resin composites determine the long‐term performance of wires and cables; however, adhesion at stainless steel interfaces is difficult. Herein, we prepared ethylene acrylic acid/linear low‐density polyethylene (EAA/LLDPE) blends with good mechanical and adhesive properties. Silane was anchored to the surface of stainless steel. The effects of silane functionalization on the adhesion surface were investigated by X‐ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. The reaction mechanism between the stainless steel, silane, and EAA/LLDPE revealed adhesion was optimized when a 3:7 volume ratio of 3‐methacryloxypropyltrimethoxysilane (MEMO): 3‐aminopropyltrimethoxysilane (A‐1110) was used to modify the stainless steel substrate. SEM images of EAA/LLDPE film peel surfaces found the silane‐treated stainless steel substrates produced rough surfaces with a uniform void indicating the silane treatment enhanced the stainless steel and EAA/LLDPE film interaction. The stainless steel and EAA/LLDPE film adhesion and water resistance improved and the peel strength after water resistance testing at 68°C for 168 h increased from 3.18 N/cm to 9.37 N/cm compared to untreated stainless steel. Silane‐modified stainless steel and EAA/LLDPE blend film composite materials demonstrate potential for application in wires and cables used in environmental corrosion‐resistant applications. POLYM. ENG. SCI., 59:1866–1873, 2019. © 2019 Society of Plastics Engineers     

Quinone‐amine polyurethanes: new coupling agents for the steel‐epoxy system

A new series of quinone‐amine polyurethanes (QAPs) were synthesized using toluene diisocyanate, polytetrahydrofuran, and an amine‐quinone monomer (AQM1). The AQM1 was synthesized and characterized using spectroscopic techniques (UV, IR, NMR). The QAP synthesis involved a two‐step process and yielded block copolymers. These polymers were characterized using infrared spectroscopy, thermal analysis methods (thermogravimetric analysis and differential scanning calorimetry) and gel permeation chromatography. Steel coupons were treated with dilute solutions of the QAPs and analyzed using surface spectroscopic techniques (X‐ray photoelectron spectroscopy, infrared reflection spectroscopy). These tests indicate that the polymer shows chemical interactions with the steel surface. The QAPs were tested for their efficiency as polymeric coupling agents to enhance the adhesion of steel to epoxy. The coupling agent treated epoxy–steel torsional joints were tested in shear. They demonstrated 10–15% dry strength improvement when compared to steel–epoxy controls. The QAPs can serve as very effective coupling agents for the steel–epoxy system. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 1338–1350, 2000     

Effect of melting temperature,coupling agent,and width on properties of ABS+20%PC/al flake‐metallized plastics

Effects of different melting temperatures (270 and 210°C), Al flake widths (0.5 and 0.8 mm), and coupling agents (gamma aminopropyl triethoxy silane A1100 and gamma glycidoxy propyl trimethoxy silane A‐187) on the properties of ABS+20%PC/Al flake‐metallized plastics are discussed. According to experiments, it is found that the aspect ratio is larger with the 270°C melting temperature and 0.8 mm Al flake, but declines with the A‐187 coupling agent. The 0.5 mm Al flakes treated with the A‐1100 coupling agent at 270°C melting temperature has better distribution in the matrix and EMI shielding effectiveness, but has a lower volume resistance. With 0.8 mm Al flakes at 210°C melting temperature, and treatment with the A‐1100 coupling agent, it produces larger ultimate tensile strength and impact strength. There is no relation between HDT and melting temperatures, Al flake widths, or coupling agents. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 1902–1909, 2000