Effect of silane treatment on the Curaua fibre/polyester interface

Abstract

Good adhesion at fibre/matrix interface of lignocellulosic fibres is crucial when substituting synthetic fibres in polymer composites. The great variability presented by those fibres requires diverse characterisation studies for better insights on fibre surface treatments and resin systems interactions. In this work, Curaua fibres were treated using silane coupling agents to improve their interfacial properties with polyester. The fibres were pre-treated using 4 wt% solution of NaOH and then treated with 5 wt% solution of (3-aminopropyl) trimethoxysilane (AMPTS) or triethoxymethylsilane (TEMS). Characterisation of the treated fibres was carried out using infrared spectroscopy, X-ray diffraction, thermogravimetric analysis and scanning electron microscopy. Fibre wettability and adhesion towards polyester was investigated using contact angle measurements and pull-out tests, respectively. The AMPTS treatment yielded a significant result of 20.2 MPa in interfacial shear strength (≈2.5 times that of the untreated fibre), attributed to the increase in availability of binding sites with polyester.

Chemical treatment of curaua fibres and its effect on the mechanical performance of fibre/polyester composites

“…The silane-treated fibres also showed superior thermal stability compared to untreated fibres. This is attributed to the strength of the polysiloxane (Si–O–Si) bonds that bind to the OH group of the fibres, forming a rigid layer on the material [27]. According to Eng [17], this behaviour was also observed in their study, where after treatment with a silane agent, the thermal stability of oil palm mesocarp fibres was superior to that of untreated fibres.…”

“…The silane created a thin layer that acted as a fibre/matrix bridge, thus enabling increased compatibility between the fibres and the polyester resin. As shown in the micrograph in Figure 4(F), a few tears were present, revealing that the fibres were torn along with the polyester resin, which indicated there was good adhesion between the treated curaua fibre and the resin [27].…”

Experimental study on evaluation and optimization of heavy metals adsorption on a novel amidoximated silane functionalized Luffa cylindrica

“…This shows that lignin and hemicellulose were partially eliminated following the alkaline treatment. Moreover, the alkaline treatment enhanced the intensity of the band at 3431 cm −1 , suggesting an increase in the –OH content of LC fibers 12 , 38 , 39 .…”