Characterization of finishing on polyamide fibres

For a fundamental approach to fibres for composite applications, it is esse ntial to develop efficient methods to analyse the composition and distribut ion of the sizing layer on the fibres. The aim of this investigation is to propose a combination of methods for surface characterization of manufactur ed finished fibres. The task is not straightforward because the composition of finishing is usually kept secret. Polyamide fibres with two different t ypes of finishing are investigated by mean of several methods: optical micr oscopy and scanning electron microscopy (SEM), x-ray photoelectron spectros copy (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS) and L angmuir balance for monolayer study. Classical methods of observation and a nalysis (microscopy, XPS and ToF-SIMS) applied directly to the fibres do no t show any difference in the two types of finishing. Only the Langmuir bala nce, demonstrates the difference between two types of fibres finishing. At the water contact, only one of the two types of fibres loses a compressible monolayer of insoluble substance on the water surface. This layer then is characterized by ToF-SIMS. An attempt to describe the finishing composition is made. Copyright (C) 2001 John Wiley & Sons, Ltd.