Influence of Bleaching Materials on Mechanical and Morphological Properties for Paper Conservation

Abstract

64O LD historical papers always are suffering from yellowing and darkness specifically after natural aging, so this study aim to evaluated some traditional bleaching materials that used in treatments of documents and books like hydrogen peroxide and sodium borohydride. Physical and chemical changes in paper sheets (cotton linter paper and book) before and after aging were studied such as color change, pH measurements, tensile strength, burst strength, FT-IR spectrum and scanning electron microscopy (SEM). The result pointed out that H 2 O 2 & NaBH 4 lead to no significant improvement in mechanical properties of the historical paper. The effect of H 2 O 2 and NaBH 4 concentration, bleaching time and pH on paper sheet bleaching process were examined. Whiteness and yellowness results of the historical paper were evaluated for both bleaching methods. From this work it is clear that, it is not desirable to utilize bleaching agents for the treatment and conservation of ancient archaeological papers, but only in the essential cases they may be used in slight concentrations to treat yellowing, staining or stains.

The Thermal Stability of Amur Cork Tree-Dyed Paper

“…The DP was primarily dependent on the molecular chain length [27,33]. The DP results of the paper samples were determined and are shown in Fig.…”

Enhancing the properties of petrified paper with cellulose nanocrystal

“…The color change in the treated papers has been measured according to International Commission on Illumination color space (CIE l * a * b *) system using Ultra-scan PRO, Hunter lab, USA, UV spectrophotometer as described by Abdel-Maksoud and Marcinkowska (2000), Rushdy et al (2017a, 2017b) and Fouda et al (2019), l * value measured darkness to brightness, a * value measured red color to green and b * value measured yellow color to blue. The total color difference (Δ E ) was calculated according to the following equation (Opermolla et al , 2021): The results of Δ l , Δ a and Δ b were obtained from the difference between the value of l *, a * and b * for the reference and treated samples, respectively (Reis-Menezes et al , 2011; Fouda et al , 2019).…”

“…The samples were conditioned for 24 h in a standard atmosphere (23°C and 50% RH) prior to measuring the tensile strength and elongation. Tensile and elongation measurements were performed on 15 mm wide strips between jaws set 100 mm apart (Junior, 1999;Rushdy et al, 2017aRushdy et al, , 2017b using QMat 5.37, Tinius Olsen according to Standard No. EN ISO 13934-1; 1999 Maximum Force and Elongation-Strip Method.…”

Recent developments in using the molecular decay dating method: a review

“…The main degradation reactions are hydrolysis of cellulose, oxidation of lignin, and thermal degradation. 58,59 Cellulose aging and lignin degradation (yellowing) in newsprint can be separated using FTIR spectroscopy. 24 Trafela et al 13 present a dating tool for historical paper based on IR spectra.…”

“…During the mid‐19th century, several technological changes make it difficult to combine historical and recent papers into a single model. The main degradation reactions are hydrolysis of cellulose, oxidation of lignin, and thermal degradation 58,59 . Cellulose aging and lignin degradation (yellowing) in newsprint can be separated using FTIR spectroscopy 24…”