Acids can weaken cellulose in paper, board, and cloth, leading to embrittlement. Acids may also be introduced by migration from other materials or from atmospheric pollution. See also pH and Acid migration. Acrylic - Back to Top A plastic noted for transparency, light weight, weather resistance, color fastness and rigidity. In addition to these qualities, acrylics are important in preservation because of their stability, or resistance to chemical change over time, a characteristic not common to all plastics.
Acrylics are available in sheets, films, and resin adhesives.
Alkaline - Back to Top Alkaline substances have a pH over 7.0. They may be added to a material to neutralize acids or as an alkaline reserve or buffer for the purpose of counteracting acids that may form in the future. A buffer may be added during manufacture or during the process of deacidification. While a number of chemicals may be used as buffers, the most common are magnesium carbonate and calcium carbonate. Alpha Cellulose - Back to Top A form of cellulose derived from cotton.