Butyl is a synthetic rubber made from isobutylene and small portions of isoprene. It is a pressure sensitive product and can be modified by adding elasticisers, tackifiers, resins and fillers. Whilst it is a well-proven technology, butyls are still new, and their nature and characteristics are yet to be fully understood and applied by many industries.
The natural structure of the butyl rubber molecules makes them very stable to weathering, age and heat whilst also having stability against a multiple of non-hydrocarbon based chemicals (including PVC plasticisers). Being an all-hydrocarbon material Butyl has low water absorption and the regular nature of the molecules allow close packing, this gives them their uniquely low permeability to gas, air and moisture.
A further feature of the butyl molecules is that they show little tendency to crystallize and rely on molecular entanglement for their internal strength. This, added with the amorphous character of the polymer, gives the product flexibility, tack and resistance to shock. Added to this, these valuable properties are maintained over a big temperature range making butyl products suitable for use in all climatic extremes.
Butyl products are non-toxic and free from Volatile Organic Content and so may find applications as a replacement for solvent based adhesive systems