Expanded vermiculite and polyvinyl acetate composite as gap filler for wooden objects conservation

Gap fillers are composites used to fill the gaps caused by deterioration processes in wooden objects. The materials commonly used in gap fillers are acrylic, vinyl, cellulosic, and epoxy resins mixed with fillers such as sawdust, glass microspheres, and paper. In this work, a gap filler composite of expanded vermiculite and polyvinyl acetate was studied for the conservation of wooden objects. Expanded vermiculite is a stable material that meets some criteria for gap filler composites. This study evaluated the properties of the proposed gap filler by comparing it to a model gap filler containing sawdust as a filler. The particle size distribution of the filler materials was measured, and the pH, modulus of elasticity, yield point, and expansion and contraction behavior as a function of the relative humidity of the air were measured. The proposed composite showed comparable properties to those of the sawdust and polyvinyl acetate composite; in some tests, the properties were better than those of the model. These data suggest potential use of expanded vermiculite as a filler in gap filler for the conservation of wooden objects. (C) 2022 Elsevier Masson SAS. All rights reserved.

Automated summary

This study explored a composite gap filler material made of expanded vermiculite and polyvinyl acetate for the conservation of wooden objects. The proposed composite showed comparable or even better properties than a model filler material containing sawdust, suggesting the potential use of expanded vermiculite as a filler for gap fillers.