catalyst
1. A substance that changes the rate of a chemical
reaction without itself being changed. A catalyst
may increase the rate (positive catalyst), or
decrease the rate (negative catalyst). The final
state or equilibrium of the reaction is not
changed by the catalyst. only the rate of
approaching the final state is changed. Examples
of catalytic action in the field of archival
preservation include the impurities in paper, such
as iron or copper, minute particles of which may
inadvertently be introduced into the paper pulp in
the beater operation. According to some
authorities, these can act as catalysts in the
formation of sulfuric or hydrochloric acid in
paper. by assisting in the conversion of sulfur
dioxide to sulfuric acid, or the chlorine
frequently used in bleaching paper pulp, into
hydrochloric acid. Leather, also, may contain
minute particles of metals which may speed up the
formation of sulfuric acid. 2. A chemical
substance added to thermosetting resinous
adhesives to speed up the cure time of such
adhesives. to increase the cross linkage of a
synthetic polymer, or to accelerate adhesive
drying. (221 , 235 , 309 )
![[CoOL]](/icons/sm_cool.gif){kind=icon}