Premium
Investigation of Degradation of Structural Adhesives under Influence of Chemicals
Author(s) -
Kjærside Storm Birgit,
Gwisdalski Milosz,
Lindvang Dan,
Rann Michael
Publication year - 2005
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.200550716
Subject(s) - adhesive , curing (chemistry) , materials science , composite material , epoxy , polyurethane , solubility , polymer , structural integrity , chemistry , organic chemistry , structural engineering , layer (electronics) , engineering
Structural adhesives are used for joining materials also under conditions, where they through the application will be influenced by many different chemicals. The adhesives can – if not protected from the chemical influence – be degradated of the chemicals. The degradation can because of the different structures of the polymers in the adhesives result in lower strength of the joining area, but can also give higher strength but brittleness. Information of the structures of the structural adhesives used in the project have been taken from the data sheets from the manufacturers and have been compared with investigation of the structures by FTIR and DSC. In the laboratory the HSP's (Hansen Solubility Parameters) of the adhesives has been determined and compared with the theoretically estimated HSP's. The estimation has mainly been done by Lydersens group contribution method. The chemical resistance of the adhesives have been foreseen by using HSP's of the adheisves and compared them with the HSP's of the chemicals. The structural adhesives were most of the epoxy types and of the polyurethane types with different curing systems. The structural adhesives should all have high strength and an opening time of more than 30 minutes. They were in the laboratory cured up after the specifications from the manufacturer and were stored one week after curing before they were influenced by hte chosen chemicals. The chemicals were chosen from their functional groups. In the laboratory the adhesives were influenced by different chemicals at room temperarture and under elevated temperature and under different periods to develope the degradation curves for the different chemicals and to foresee the degradation time of the adhesives before their properties were not acceptable any more. The structure after influence of the chemicals is studied by FTIR. The results of the investigations have been that it is possible to estimate the degradation by using the HSP's of the adhesives and the chemicals, but to estimate the time before degradation has been so serious that the properties of the adhesives are not acceptable any more, it is necessary to add laboratory investigations to the HSP comparisons of adhesives and chemicals. The comparison of the HSP and of the chemicals by which the adhesives can be in its lifetime has seen to be usefull especially if the chemicals are pesticides.