Abstract
Data produced using both unsized and aminopropyltriethoxysilane (APS) coated fibre will be shown and discussed. By applying a novel method of single fibre thermal conditioning (sf-TC) it was found that retained fibre strength is, in some cases, underestimated and that the temperature range 400-500 °C is the most critical for thermally induced strength loss. This is not related to degradation of the APS surface coating, but rather is likely linked to fundamental changes occurring in the glass network or at the fibre surface. X-ray Photoelectron Spectroscopy (XPS) analysis of treated fibres was performed, but it was not possible to measure any significant changes in surface chemical state. Analysis of water volatilized from unsized fibre was performed using a furnace connected to quadropole mass spectrometer. An asymptotic minimum in volatilized water is reached between 400-500 °C.