FTIR-ATR och SEM användes för att analysera olika typer av ytbehandlingar då de utsatts för accelererad åldring. Ytbehandlingarna som analyserats var olika typer av akrylatemulsioner, en UV-härdande produkt, en syrahärdande produkt och en vattenburen UV-härdande produkt. Två olika metoder för att kvantifiera degraderingen av färgfilmerna undersöktes, POI-metoden och karbonylindex. Båda dessa metoder går ut på att jämföra antingen arean eller höjden av två FTIR toppar med varandra. Studien avslutades med en topografisk analys av proverna mha SEM. FTIR-ATR visade sig vara ett effektivt instrument för att undersöka degraderingen av färgfilmer. POI-metoden användes för att kvantifiera 9 av 12 ytbehandlingar och ranka Serwin Williams produkter från bäst till sämst utomhusbeständighet. De ytbehandlingar som uppvisade störst kemiska förändringar hade alla aromat komponenter. Dessa absorberar UV-ljus och påverkas därför extra mycket av fotooxidation. De ytbehandlingar som avvek från de resterande var klarlacker och den vattenburna UV-härdande färgen. Klarlackerna visade minimala kemiska förändringar och den UV-härdande produkten minskade i POI, olikt resterande ytbehandlingar. Karbonylindex visade sig inte vara en effektiv metod för att bedöma degradering av färgfilmerna då värdet ökade för två av produkterna som testades och minskade för de två andra. Karbonyltoppen vid 1720cm-1 kan dock analyseras utan att beräkna karbonylindex då den kan ge mycket intressant information om den förändrande karbonylkompositionen. Testerna av topografin med SEM visade mycket detaljerade bilder av degradering processen som föll i linje med resultaten från FTIR analysen. / FTIR-ATR and SEM were used to analyze different types of coatings exposed to accelerated ageing. The coatings valuated in this study were different types waterborne acrylic emulsions, a UV-curing coating, an acid curing coating and a waterborne UV-curing coating. Two different ways to quantify the degradation with FTIR-ATR were explored, the POI method and carbonyl index. Both methods are based on comparing the height/area of specific FTIR peaks with one another. The study was concluded with a topographic analysis with SEM for some of the samples. Results from this study shows that FTIR-ATR is an effective tool to explore the degradation of different types of coatings. The POI method was successfully used to quantify the degradation concerning 9 of the 12 studied coatings and ranking the coatings from best to worst. Coatings with aromatic components mounted the biggest chemical changes thanks to their instability when exposed to UV-radiation. Coatings that deviated from the rest were acrylic clearcoats and the waterborne UV-curing coating. Clearcoats mounted minimal chemical changes in the FTIR-ATR, and the waterborne UV-curing coating was degraded in a way that it’s POI value decreased during ageing, unlike all other coatings tested. Carbonyl index proved insufficient for quantifying degradation in this study, although the carbonyl peak around 1720 cm-1 can be analyzed manually to attain valuable information about the changing carbonyl composition. Topographical analysis with SEM gave valuable information showing detailed pictures of the degradation which all were in line with the results from the FTIR spectrums.

This paper reviews the effects of accelerated aging with increased humidity and temperature on cellulose-based composites. The composites consist of a matrix of plastic reinforced with cellulose fibers. The company Biofiber Tech Sweden AB provided four different composites and a conventional polyolefin as reference. The aim was to examine changes in mechanical properties, chemical composition and appearance after aging, as well as variations between materials. Two different climate conditions were tested, 85% RH and <10% RH, both in 90℃. A climate chamber and an oven were used to create the extreme environmental conditions. To analyze the results, tensile testing and FTIR were performed, and color intensity and density were measured. All samples decreased in color intensity throughout aging, and dark irregularities appeared on some of the samples exposed to high humidity, which may be due to fungal formation. The tensile testing showed a general difference between high and low RH and the toughness showed a tendency to decline with aging in high humidity for many samples. The FTIR measurements also did not show any general trend. To improve the study, it would be desirable to age the material for a longer time and at a higher temperature. Overall, more samples and measurements within each characterisation technique would be needed to achieve more reliable results. Nevertheless, this study hopes to be a starting point for further research on the long-term durability of Biofiber Tech’s composites.