Plasticization of Polyurethane Adhesives and Sealants
Edward M Petrie
- Dec 13, 2011
This article will first examine the reasons that external plasticizer modification may not be necessary with polyurethane adhesives and sealants. It will then review the possible value that can be achieved from using added plasticizers. The article will also review the types of plasticizers that have been historically employed in polyurethanes as well as plasticizers that have been recently introduced to the market. Plasticizers are generally added to adhesive and sealant formulations to achieve a variety of properties such as lower viscosity, reduced hardness, and increased elongation. The selection of the plasticizer has to be made carefully to achieve these characteristics without loss of adhesion. The type of plasticizer that is utilized will depend on the properties that one is trying to achieve as well as its compatibility with the base polymer and other ingredients in the formulation. Plasticizers are often not necessary in polyurethane adhesives and sealants. The urethane polymer molecule is typically flexible enough at low temperatures that plasticization may not required.
posted by Paul Rohrer, Consulting/ Training/ Education at Paul Rohrer Consulting
This article succeeds to summarize the basic principles of PU physics and mechanics in an excellent easily understandable manner. It also tackles the regulatory problematics in the EC re. the phthalates, but might have treated that latter issue in more detail. Unfortunately I did not find two important aspect of plasticizers, namely the volatility and the compatibility.