In situ polymerization of urethane-urea copolymers for tuff consolidation

Two different diisocyanates were investigated as co-monomers for in situ polymerisation of poly(urethane-urea) into Neapolitan yellow tuff for conservation and restoration purpose. The obtained copolymers were characterised by means of FTIR spectroscopy, whereas the protective and consolidating efficiency of the performed treatments was evaluated through water capillary absorption, water vapour permeability and abrasion resistance measurements. The distribution and the penetration depth of the synthesized copolymer were also analysed applying micro-FTIR. The morphology of treated tuff was investigated by SEM. It was shown that comparatively higher protective and consolidating properties are achieved by using 1,6-diisocyanatohexane as monomer for in situ polymerisation.