It was demonstrated that Butyl rubber can be modified with polyolefins by chemically reacting the two components, with chlorinated melamines and a metal oxide resulting in a considerable improvement in ozone resistance compared to simple physical blends. Many of the properties of such blends can be altered according to the type and the amount of polyolefin used. The reacted blends can be used alone or added to regular Butyl compounds and have the following general properties a Good oil and fuel resistance, particularly to aromatic fuels b Excellent chemical resistance c Good electrical properties d Highly ozone resistant e Low permeability f Low temperature flexibility below -50C g Low water absorption h Can be processed on conventional rubber equipment i Extrudes smoothly with low die swell. Throughout the range of properties it is evident that the modification of Butyl rubber with polyolefins can result in practical advantages that will increase the range of applications for Butyl rubber. Author
Annual Wire and Cable Symposium (12th) 4-6 Dec 1963.