Polyurethane is any polymer consisting of a chain of organic units joined by urethane links. These polymers are formed through polymerization by reacting a monomer containing at least two isocyanate functional groups with another monomer containing at least two hydroxyl (alcohol) groups in the presence of a catalyst. Whew! In other words - it's a high-tech polymer formed by the reaction between two precursor materials. By adjusting the individual properties of the precursors, an almost limitless variety of polyurethanes can be produced. This flexibility in formulation allows one to custom-engineer the polyurethane to meet the unique demands of the project.
There is a large range of polyurethane adhesive products available. Different chemical combinations result in different properties in polyurethanes. The chemical make-up can be altered to produce different levels of stiffness, density and hardness. All this makes polyurethanes versatile over many industries, such as: automotive, aerospace, construction, textile, wood working, book binding and hardscapes. Out of the three: Polyester, Epoxy and Polyurethane – Polyurethanes are the most flexible (ie: least rigid). Polyurethane, as an adhesive, was first developed in 1985 and has gone through many changes to be the product it is today – especially in cure speed. They are available in one-part or two-part systems. The two part systems require a catalyst.
Benefits of Polyurethanes:
- Long open time
- Flexibility
- Resiliency
Specific uses can be:
- Aesthetic repairs to stone surfaces
- Retaining wall capping
- Subfloor construction
- PreFab or modular construction
- Book Binding
- Binding leather soles to leather and synthetic uppers (shoes)
So, what do you think of these structural adhesives? Which do you prefer to work with and why?
No comments:
Post a Comment