Synergistic ATRP-IL approach for improving the mechanical properties of fragile palm leaf manuscripts

This study proposes a novel conservation strategy combining atom transfer radical polymerization (ATRP) and ionic liquid (IL) treatments to modulate the mechanical properties of fragile palm leaf manuscripts. ATRP was employed to graft methacrylate polymers (PAAEM, PHMA, and their copolymers) onto lignin-rich regions of degraded samples, forming a reinforcement network within the cell walls. Concurrently, 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) was applied to enhance flexibility. ATRP consolidation significantly improved bending strength up to 37.9 MPa for highly degraded samples by thickening fiber cell walls. Ionic liquid treatment increased deflection to levels comparable to sound manuscripts. The synergistic application of ATRP (PAAEM) and IL achieved a toughness of 0.56 J/m³, 3.3 times as high as untreated samples. FTIR and histochemical staining demonstrated successful polymer grafting and reduced exposure of degraded polysaccharides. The study bridges advanced polymer chemistry and heritage conservation, offering a new pathway for preserving fragile cultural artifacts.