A New Formulation for the Treatment of Acid-Deterioration (Red Rot) in Historic Leathers

Lama, A. (Speaker), Paula Antunes (Speaker), Anthony D Covington (Speaker), Jeffry Guthrie-Strachan (Speaker), Yvette Fletcher (Speaker)

Activity: Academic Talks or PresentationsInvited talkResearch

Description

Conservation of acid-deteriorated historic leather (also commonly known as red rot) is an on-going concern as current treatment options are limited. Various products such as aqueous-based buffer salts, imidazole, ammonia vapour and aluminium di(isopropoxide) acetoacetate ester chelate (referred to as aluminium alkoxide in this study) have been used to treat acid-deterioration in historic leathers. Among the various products studied, aluminium alkoxide was found to be the most effective. However the effect of aluminium alkoxide when applied on its own may be limited due to its short-term stabilisation effect.

A new formulation consisting of aluminium alkoxide and 5-ethyl-1-aza-3, 7-dioxabicyclo [3.3.0] octane (oxazolidine II) was used to treat acid-deterioration in historic leather. Acid-deteriorated and artificially aged mimosa-tanned leathers were treated with the new formulation and aged further by exposure to an acidic environment at 40°C and 30% relative humidity for up to 12 weeks. The acidic environment was created using sulfur dioxide and nitrogen dioxide. Corresponding untreated acid-deteriorated and artificially aged mimosa tanned leathers were used as a negative control. The impact of the treatments and artificial ageing was determined by measuring the hydrothermal stability of the leather samples using differential scanning calorimetry (DSC) and pH of the aqueous extract.

The results obtained showed that the formulation has collagen-stabilising properties, acid-buffering capacity as well as the capability to provide long-term protection against an artificially-created acidic environment.
Period24 Nov 2015
Event titleXXXIII International Congress of International Union of Leather Technologists and Chemists Societies
Event typeConference
Conference numberXXXIII
LocationNovo Hamburgo, Brazil