TY - JOUR
T1 - The photo-stability of acrylic tri-block copolymer blends for the consolidation of cultural heritage
AU - Del Grosso, Chelsey A.
AU - Poulis, Johannes A.
AU - de la Rie, E. René
PY - 2019
Y1 - 2019
N2 - A variety of adhesives are used for the conservation of paintings. These materials include natural adhesives such as animal glues, waxes, and gums which may chemically degrade over time resulting in unwanted discoloration and mechanical failure. Synthetic adhesives have been introduced to address these concerns. However, most consolidating adhesives have not been specifically formulated and tested to meet the high demands of conservation, ultimately resulting in undesirable physical and mechanical properties. Additionally, some synthetic adhesives are less stable and may cross-link making it difficult to remove years after application. This paper investigates the photo-stability of commercially available tri-block acrylic copolymers (PMMA-PnBA-PMMA) to assess their potential long-term serviceability as consolidants for flaking paint. These copolymers were combined with synthetic low molecular weight resins to reduce viscosity of the adhesive and provide tack. The polymer blends underwent accelerated aging under simulated indoor conditions. Blends were analysed for degradation using Fourier-transform infrared spectroscopy and size exclusion chromatography. Upon irradiation, acrylic copolymers (PMMA-PnBA-PMMA) undergo shifts to higher and lower molecular weight, suggesting that degradation occurs by polymer cross-linking and chain scission. Furthermore, the acrylic copolymer degradation rate was influenced by the type of low molecular weight resin. However, with the addition of a hindered amine light stabilizer these blends exhibited minimal changes in molecular weight. Lastly, the peel strength of the blends were investigated and shown to have comparable peel strength to a popular commercial material, Paraloid™ B-72, often used in consolidation thus showing their promise for use within cultural heritage.
AB - A variety of adhesives are used for the conservation of paintings. These materials include natural adhesives such as animal glues, waxes, and gums which may chemically degrade over time resulting in unwanted discoloration and mechanical failure. Synthetic adhesives have been introduced to address these concerns. However, most consolidating adhesives have not been specifically formulated and tested to meet the high demands of conservation, ultimately resulting in undesirable physical and mechanical properties. Additionally, some synthetic adhesives are less stable and may cross-link making it difficult to remove years after application. This paper investigates the photo-stability of commercially available tri-block acrylic copolymers (PMMA-PnBA-PMMA) to assess their potential long-term serviceability as consolidants for flaking paint. These copolymers were combined with synthetic low molecular weight resins to reduce viscosity of the adhesive and provide tack. The polymer blends underwent accelerated aging under simulated indoor conditions. Blends were analysed for degradation using Fourier-transform infrared spectroscopy and size exclusion chromatography. Upon irradiation, acrylic copolymers (PMMA-PnBA-PMMA) undergo shifts to higher and lower molecular weight, suggesting that degradation occurs by polymer cross-linking and chain scission. Furthermore, the acrylic copolymer degradation rate was influenced by the type of low molecular weight resin. However, with the addition of a hindered amine light stabilizer these blends exhibited minimal changes in molecular weight. Lastly, the peel strength of the blends were investigated and shown to have comparable peel strength to a popular commercial material, Paraloid™ B-72, often used in consolidation thus showing their promise for use within cultural heritage.
KW - Acrylic copolymer
KW - Adhesion
KW - Conservation
KW - Consolidating adhesive
KW - Hindered amine light stabilizer
KW - Hydrogenated hydrocarbon
KW - Low molecular weight resin
KW - Painting
KW - Photo-chemical stability
KW - T-peel strength
KW - Urea-aldehyde
UR - http://www.scopus.com/inward/record.url?scp=85056781738&partnerID=8YFLogxK
U2 - 10.1016/j.polymdegradstab.2018.11.010
DO - 10.1016/j.polymdegradstab.2018.11.010
M3 - Article
AN - SCOPUS:85056781738
VL - 159
SP - 31
EP - 42
JO - Polymer Degradation and Stability
JF - Polymer Degradation and Stability
SN - 0141-3910
ER -