Growing concern over volatile organic compounds (VOC) and other emissions is motivating adhesive and sealant formulators to capture and recycle solvents, reduce solvent use, or switch to solvents with better environmental profiles. Although environmentally suitable, "drop-in" replacements for conventional solvents are still a distant future vision, a strong evolutionary path is developing to complete this quest.
Even in "water-based" adhesives and sealants, solvents are sometimes used in conjunction with water to dissolve or suspend components or to provide a more efficient film forming function. For example, many water reducible coatings contain small amounts of a "co-solvent" such as a glycol ether or alcohol to aid in coating and handling.So even in this sub-segment of the industry, solvents are carefully selected and controlled relative to their effect on the environment.
This article reviews new solvents that have been developed for the purposes of (1) formulating and processing adhesives, (2) cleaning equipment.