Exploitable results Interphase characterisation and study of structure-property relations of fibre-reinforced polymers; INTERPHASE The necessity to use new surface characterisation methods was pointed out and the technique of LEIS (Low Energy Ion Scattering) could determine the coverage of active compounds on the surface. Good correlation between thermodynamic work of adhesion and adhesion strength was shown for all those systems, in which no transcrystalline effects of the interphase or covalent bonds occur and thus limit the use of the empirical Schultz-Nardin equation. The micromechanical tests proved effective in ranking different degrees of adhesion, however there still exists a controversy over interpretation of the data because of the material dependent and failure dependent criteria. Several examples of good agreement of results achieved using different test methods were given as an outcome of the network. Several examples were shown within the frame of the Thematic Network that confirm the applicability and derivation of results that characterise the adhesion strength of a given fibre-matrix system and provide comparable data from one lab to the other. The results of the project are available in about 200 publications and 8 periodic progress reports. The link between interfacial mechanical tests and mechanical performance of composites has been demonstrated in some programmes. The interphase network was fortunate to have various facilities available for tackling the problems associated with the interphase and interface in composite materials. This data was very useful in understanding the results of the differing micromechanical tests. The new sensitive atomic force microscopy tool - nanoindentation and phase imaging - was used to identify extent and Young modulus of interphases. This data can be used for improved modeling. The issues relating to data-reduction generally refer to the properties of the interphase region and of the matrix and to their non-linear, elasto-plastic and/or elastic behaviour. Further research work is needed to specify the effects of reversible adhesive bond separation and other kinds of bond failure. Future tasks are to identify and quantify the stresses in both fibre and resin in a number of combinations. This body of knowledge within the interphase networks makes it possible to further develop our understanding so that a unified interface or stress transfer parameter can be identified with appropriate experimental measurements and data reduction analysis. There is a necessity for joint basic research using the different skills of each member. The network mechanism has not funded specific research on specific fibre-resin systems nor specific test methods or modeling. However, the general consensus from the network is that in order to make further progress, systems which are fairly fundamental need to be studied from a modeling point of view, an experimental point of view and a test method point of view. There is a need for a New Network that includes manufacturers of the fibres, the resins and possibly the sizings generating interphases. Searching for OpenAIRE data... There was an error trying to search data from OpenAIRE No results available
