Gamma-aminopropyl Triethoxysilane Research Articles

Modification of DABA/BMI Composites by Silane Compound and Fumed SiO<sub>2</sub>

In this present investigation, at first, Dially bisphenol A (DABA)/Bismaleimide (BMI) system was modified with gamma-aminopropyltriethoxy silane (KH550). The objective of the work was to study the effect of addition of various weight percentages of KH550 into BMI/DABA composites on its mechanical properties, thermal properties and morphorogy. Further modification was carried out with fumed silica. The role of KH550 was discussed in these composites prepared. Nancomposites were characterized by differential DSC, TGA, and scanning electron microscopy SEM. TGA results confirmed that the heat stability of the nano composite DABA/BMI/KH550 is improved compared with DABA/BMI system. SEM results indicated that the fumed silica dispersed homogeneously in DABA/BMI/KH550 matrix on nanoscale. Mechanical results shows that newly developed system has improved bending modulus to 4.0GPa, while with incorporation of fumed SiO2 impacted strength also improved to 20.60kJ/m2.

Electrical and thermophysical properties of epoxy/aluminum nitride nanocomposites: Effects of nanoparticle surface modification

The traditional epoxy resin used for electrical and electronic industry has a poor thermal conductivity and no longer meets the increasingly cooling requirements of electric equipments and electronic devices. Ceramic nanoparticles with high thermal conductivity and low dielectric constant represent good candidates to improve the thermophysical properties of epoxy resin. This paper reports the effects of surface modification of AlN nanoparticles on morphology, glass transition, electrical property and thermal conductivity of the epoxy composites. Gamma-aminopropyl triethoxysilane was used as a silane coupling agent for the surface modification of the AlN nanoparticles. It was found that the surface modification of the nanoparticles not only improved the dispersion of the nanoparticles, but also showed an enhancement in electrical and thermophysical properties of the epoxy composites. The surface modification technology presented a strategy to prepare nanocomposites having high thermal conductivity simultaneously with low dielectric loss.

Electrical, thermophysical and micromechanical properties of ethylene-vinyl acetate elastomer composites with surface modified BaTiO3 nanoparticles

In this study, we investigated the influence of the surface modified BaTiO3 nanoparticles on the electrical, thermophysical and micromechanical properties of ethylene-vinyl acetate (EVM) vulcanizates. Gamma-aminopropyl triethoxysilane was used as a silane coupling agent for the surface treatment of the BaTiO3 nanoparticles. It was found that the incorporation of surface modified BaTiO3 nanoparticles into the EVM matrix not only increased the permittivity, thermal conductivity and the mechanical strength but also showed a comparative dielectric loss tangent with pure EVM vulcanizates. In particular, the nanocomposites exhibit relatively high dielectric strength and good ductility even at the loading level of 50 vol%. The improved properties not only originate from the homogeneous dispersion of BaTiO3 nanoparticles but also should be ascribed to the strong interfacial interaction between the surface modified BaTiO3 nanoparticles and EVM matrix. We also investigated the dielectric relaxation behaviour of the BaTiO3 filled EVM nanocomposites by using Jonscher's theory of universal dielectric response.

Synergy effect of silane and CTAB on corrosion-resistant property of low infrared emissivity Cu/polyurethane coating formed on tinplate

Synergy effect of the surface modification of copper (Cu) by surfactant, cetyl trimethyl ammonium bromide (CTAB) and coupling agent, gamma-aminopropyltriethoxy silane (KH550), on the corrosion-resistant property of low infrared emissivity Cu/polyurethane (PU) coating formed on tinplate was evaluated. Infrared spectra revealed an obvious interaction between Cu and PU induced by the addition of KH550, which implied that KH550 can improve the chemical interfacial interaction while CATB only improved the physical interaction between Cu and PU. The corrosion behavior of Cu/PU coating has been investigated with potentiodynamic polarization. Results have shown that the interfacial interaction between Cu and PU was improved by the synergy effect of proper amount of KH550 and CTAB, benefiting to the dispersion of Cu and the low porosity of Cu/PU coating, which keeps the low infrared emissivity and increases the corrosion resistance of the Cu/PU coating formed on tinplate.

Effects of surface modification of carbon nanotubes on the microstructure and electrical properties of carbon nanotubes/rubber nanocomposites

Effects of the surface modification of multi-walled carbon nanotubes (MWCNTs) by surfactant, hexadecyltrimethylammonium bromide (CTAB) and coupling agent, gamma-aminopropyltriethoxy silane (KH550), on the microstructure and electrical properties of rubber composites loaded with MWCNTs were studied. The results show that the CATB can improve the dispersion of MWCNTs, but it cannot improve the interfacial interaction remarkably between MWCNTs and rubber. While the use of KH550 is benefit of the dispersion of MWCNTs and induces the strong interfacial interaction, which often hinders electron transport in the composites. These results are further confirmed by the temperature and pressure dependencies of the electrical properties of the composites.

Studies of interactions between silane coupling agents and cellulose fibers with liquid and solid‐state NMR

The hydrolysis of three alkoxy-silane coupling agents, gamma-methacryloxypropyl trimethoxy silane (MPS), gamma-aminopropyl triethoxy silane (APS), and gamma-diethylenetriaminopropyl trimethoxy silane (TAS), was carried out in ethanol/water solutions (80/20 w/w) at different pH values and followed by 1H, 13C and 29Si NMR spectroscopy. Acidic media were found to stabilize the hydrolyzed forms. As expected, the formation of silanol groups was followed by their self-condensation to generate oligomeric structures, yielding, ultimately, solid homopolycondensated structures, as analyzed by 29Si and 13C high-resolution solid-state NMR. Hydrolyzed MPS in acidic media was then successfully adsorbed onto a cellulose surface and the ensuing substrates submitted to thermal treatment at 110-120 degrees C under reduced pressure, in order to create covalent bonds between cellulose and the coupling agent.

The effect of silane coupling agents on radiata pine fibre for use in thermoplastic matrix composites

Abstract Gamma-aminopropyltriethoxysilane (GS) and dichlorodiethylsilane (DCS) were employed for surface modification of radiata pine ( Pinus radiata ) wood fibre. Levels of fibre moisture were carefully controlled to optimise chemical and hydrogen bonding with these silane coupling agents. The effect of pre-treatment using 2% sodium hydroxide, shown to be effective in assisting silane coupling for other natural fibres [Composites, Part B: Engng 30 (1999) 321], was also investigated. X-ray photoelectron spectroscopy and nuclear magnetic resonance (NMR) were used to characterise modification of the wood fibre. Concentrations of up to 3.2 wt% Si were obtained on the fibre surface due to silane coupling, however, pre-treatment was found to dramatically reduce this value. NMR provided evidence that coupling had occurred between the fibre and DCS by reaction producing ether linkages between the hydroxyl groups on the wood fibre and silane. Pre-treatment and treatment were found to have an insignificant effect on fibre strength. Composite sheets were produced by blending fibre (5, 10 and 20 wt%) with polyethylene followed by extrusion. An increase in strength was obtained at fibre contents of 5 wt% for all treatments compared to composites with untreated fibre. This is believed to be mainly due to increased compatibility of the fibre surface to polyethylene. However, there was no such improvement obtained at higher fibre contents. Evidence suggests that the production of voids is limiting composite strength.

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