STUDY OF PROTECTIVES OBTAINED FROM NATURAL RESOURCES FOR THE CONSERVATION OF STONE

Silvia Salvini 1,3 , Barbara Sacchi1, Piero Frediani 1,2

1 Institute for Conservation and Valorization of Cultural Heritage (ICVBC-CNR), Via Madonna del Piano 10, Sesto Fiorentino (FI), silvia.salvini@gmail.com

2 Department of Chemistry “Ugo Schiff”, University of Florence, Via della Lastruccia 13, Sesto Fiorentino (FI)

3Specialization School in Architectural and Landscape Heritage, University of Genoa, Stradone Sant’Agostino 37, Genova

ABSTRACT

Stone monuments and artefacts are the largest part of the cultural heritage and the Science for Conservation studies innovative protective and consolidant products.

In this work, three polymers were obtained from lactic acid and their behavior was tested as protectives: PLLA, PLLA-FLK, PLDA-FLK. The last two products were copolymers containing a perfluoropolyether moiety in order to improve their hydrophobicity and stability. The polymers were synthesized through ROP (Ring Opening Polymerization), and characterized using different techniques like NMR and FT-IR spectroscopies, differential scanning calorimetry (DSC) and gel permeation chromatography (GPC). The polymers were tested as protectives on four different types of stones examining their efficiency and colorimetric variations when applied on the samples. Ageing tests were performed both on natural (in laboratory and outdoor) and artificial (climatic chamber, UV radiation) conditions.

Key-words: lactic acid polymers, protectives, Apuan Marble, porous stones, Serena Stone