Effects of fibre surface silanisation on silica fibre/phenolics composites produced by resin transfer moulding process

Abstract

The effects of fibre surface silanisation on silica fibre/phenolics composites produced by the resin transfer moulding (RTM) solution impregnation route were investigated. Diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy and micro-Wilhelmy method were used to evaluate the surface properties of silanised silica fibre. The interlaminar shear strength (ILSS) measurements and morphological observations of the silica fibre/phenolics composites were also performed. The interactions occurring between silica fibre and the components of phenolic resin solution affect the dynamic adsorption behaviour of phenolic resin onto fibre reinforcement. The competitive adsorption of ethanol as solvent onto silica fibre suppresses that of phenolic resin. Fibre surface silanisation by c-aminopropyl-triethoxysilane (c-APS), c-glycidoxypropyl-trimethoxysilane (c-GPS) and c-methacryloxypropyl-trimethoxysilane (c-MPS) leads to the improvement of mechanical interfacial properties of silica fibre/phenolics composites on one hand and decreases the inhomogeneities of resin distribution and mechanical interfacial properties at different regions of the RTM product on the other hand.

Capillary Effects in Fiber Reinforced Polymer Composite Processing: A Review

“…In the absence of capillary effects, saturated permeability decreases due to the stronger resin-fiber interactions experienced by an infiltrating resin in the presence of a dedicated sizing. The decrease in capillary driven unsaturated flow was in agreement with the intra-yarn flow analysis as reported by Wang et al (Wang et al, 2006) or Palmese and Karbhari (Palmese and Karbhari, 1995;Karbhari and Palmese, 1997) and was attributed to resin-fiber interactions to differences specific surface free energy (Steenkamer et al, 1995;Karbhari and Palmese, 1997). Capillary pressures moreover are reported to be lower for dedicated sizings due to the consequent increase of the contact angle.…”

Strong Effect of Process Parameters on the Properties of Boron-Containing Phenolic Resins with High Char Yield

“…In general, the surface tension of PR solution increases as the temperature increases, due to the curing of PR and evaporation of the solvent. However, when the temperature is relatively lower than the cured temperature of PR, increasing the temperature is found to be favorable for the mixing of PR and solvent, resulting in a lower value of surface tension of PR solution, similar to results revealed in Table 1 [32][33][34]. In addition, the value of surface tension of the B-containing PR solution is lower than that of common PR solution under the same conditions, demonstrating that the introduction of B element could decrease surface tension of the PR solution, which is beneficial for infiltration into the fiber braid.…”

“…This surface tension decreases with increase in concentration of the PR solution. Low concentration means a high content of absolute ethanol, while the surface tension of absolute ethanol is larger than that of PR, leading to a high surface tension, compared with that of high concentration of PR solution [32][33][34]. In general, the surface tension of PR solution increases as the temperature increases, due to the curing of PR and evaporation of the solvent.…”

Improved interfacial adhesion of carbon fiber‐reinforced polydicyclopentadiene layered composite material by modification of norbornene derivatives

“…40 In Figure 4B, the C C (H) group is located at 284.7 eV, while more C O peaks appear at 286.3 eV, possibly indicating a grafting reaction between CF C-R and TOS Si-OR to form C O Si bonds. 36 In Figure 4C, the C C (H) group is located at 284.8 eV, while the C O peak at 286.3 eV decreases relatively, while the O C O peak at 288.9 eV increases significantly. These changes may be due to the presence of ester groups in NB-TBE, which increases the content of ester groups grafted onto the surface of CF during the modification process.…”

“…35 The absorption peaks of 1700 cm À1 , corresponding to the stretching vibration of the C O bond in esters and anhydrides, indicate that NB-TBE and NA were successfully grafted onto the surface of CFs after treatment, which should improve the surface condensation reaction and strengthen interfacial adhesion. 36 The Si O bond at 1087 cm À1 was caused by the reaction of TOS and hydroxy group only appearing in IR spectra of CF-TOS-5. 37 IR spectra of untreated CF and CF-TOS/NB-TBE/NA-5 all possess the stretching vibration of the OH bond at around 3400 cm À1 , the symmetric and antisymmetric stretching vibrations of the C C bond at 2916 cm À1 and 2847 cm À1 , and the stretching vibration of the C C bond at 1613 cm À1 .…”