1.13 Study of the Effects of Sulfur Dioxide and Nitrogen Dioxide on Deacidified Papers-Part 1

Francoise Flieder Centre de Recherches sur la Conservation des Documents Graphique (CRCDG)
Daniel Grosjean and Associates
The Getty Conservation Institute
Los Angeles County Museum of Art

Floreal Daniel
Francoise Leclerc
James R. Druzik
Daniel Grosjean
Antoinette Van Neste
Edwin Williams II
James Druzik
Eric Hansen
Victoria Blyth-Hill
Period of Activity: 1/87 to 4/89 

Project Abstract
We examined the effects of two gases known to generate strong acids in paper, sulfur dioxide and nitrogen dioxide, on papers buffered against acidic attack through conventional conservation treatments.

Three papers, a rag vellum, 100% chemical bleached pulp, and a mechanical pulpnewsprint newsprint; were deacidified both aqueously and nonaqueously. Magnesium bicarbonate, calcium hydroxide, sodiumtetraborate, calcium bicarbonate, barium hydroxide, and magnesium methyl carbonate were used in the deacidification process. Exposures were at 13 ppm for SO2 and 4 ppm for NO2 at 30 C and 90% RH. The results were evaluated through changes in pH, alkaline reserve, copper number, sulfur pickup, changes in tensile and burst strength, and DP.

Major Findings
Some findings have been presented in Ottawa but no information on the conference nor an abstract of the presentation has been submitted to GCI.

Primary Publications
Centre de Recherches sur la Conservation des Documents Graphiques, Rapport d'Activite 1987, Centre National de la Recherche Scientifique, ed. Francoise Flieder, 1987.

"Comparative Study of Different Deacidification Techniques for Papers Exposed to Atmospheric Pollution," pp. 2-6.

Work conducted by Floreal Daniel covering the exposure of two types of paper, 100% chemically bleached book paper, and a mixed 60% mechanical pulp/40% chemical bleached pulp, to 13 ppm of SO2 and 4 ppm NO2 for 12 weeks. Temperature was maintained at 28 C and a constant 90% relative humidity. Changes from exposure were monitored at intervals by pH and alkaline reserve, absorption of total sulfur, reduction of DPv, mechanical strength, copper number, and color change. color change.; Further work is suggested.

Les Documents Graphique et Photographiques: Analyse et conservation, Travaux du Centre de Recherches sur la Conservation des Documents Graphique, 1986-1987, Archives Nationales-La Documentation Francaise, Paris, ed. Francoise Flieder, 1988. "Study of the Effects of Pollution on Deacidified Papers," by Floreal Daniel, Francoise Flieder, and Francoise Leclerc, pp. 53-92.

A review of paper chemistry deacidification and experimental work to date is presented. The conclusions are summarized: (I) Ranked in terms of reduction of pH for edition and newsprint papers-(1) newsprint, 90% RH, (2) edition, 90% RH, (3) edition, 50% RH. (II) All deacidified papers absorbed more total sulfur than their controls with borax exceeding magnesium bicarbonate by 12 weeks. (III) Copper number (a measure of paper oxidation) increased during the 12-week exposure, more so at 90% than at 50% RH, for both papers. The newsprint paper control showed a larger increase in copper number than the deacidified newsprint at 90% RH, while the edition paper reversed the order-deacidified paper was more highly oxidized than the control. (IV) All samples at both humidities showed a reduction of tensile and burst strengths. (J.R.D.)

Flieder, F., F. Leclerc, and J-M. Arnoult, "La Desacidification de Masse des Papiers en France," Technologie Industrielle Conservation Restauration de Patrimoine Culturel, Nice, September 19-22, 1989.

ABSTRACT-None available.