Consolidation of degraded polyurethane foams by means of polysiloxane mixtures: Polycondensation study and application treatment

Publication date: December 2018Source: Polymer Degradation and Stability, Volume 158Author(s): Céline Daher, Isabelle Fabre-Francke, Nathalie Balcar, Gilles Barabant, Sophie Cantin, Odile Fichet, Hervé Chéradame, Bertrand Lavédrine, Agnès Lattuati DerieuxAbstractPolyurethane (PUR) ester foams are found in 20th century museum collections in a variety of artworks and objects. Unfortunately PUR ester foams are prone to degradation, and present – among other plastic materials – important conservation issues. They are very sensitive to moisture, and their hydrolysis leads to several degradation processes such as yellowing and embrittlement, drastically changing the artwork aspect and materiality. Few researches were conducted on the consolidation of PUR ester foams. In this paper, a curative treatment that should limit the hydrolysis of the degraded PUR foams, and that mechanically consolidate the foams’ structure is presented. This work focuses on the innovative use of alkoxysilanes mixtures and on their application modes on foam samples. Different binary mixtures of OTMS (n-octyltriethoxysilane, hydrophobic and trifunctional) and AMDES (3-aminopropylmethyldiethoxysilane, hydrophilic and bifunctional) in various proportions were tested. The kinetic evolution of their polycondensation using spectral decomposition of FTIR spectra revealed that OTMS does not react with atmospheric water vapor and that the presence of an amine (AMDES) is required to initiate its polyconden...

Source: Polymer Degradation and Stability - November 7, 2018 Category: Chemistry Source Type: research