Abstract: Disclosed are electrically conductive and semiconductive devices utilizing polymers having resistance to water treeing and good dielectric properties. The polymer comprises ethylene polymerized with at least one C.sub.3 to C.sub.20 alpha-olefin and optionally at least one C.sub.3 to C.sub.20 polyene. The polymer utilized has a density in the range of about 0.86 g/cm.sup.3 to about 0.96 g/cm.sup.3, a melt index in the range of about 0.2 dg/min to about 100 dg/min, a molecular weight distribution in the range of about 1.5 to about 30, and a composition distribution breadth index greater than about 45 percent. For the polymer utilized, the tree rating is generally less than about 40, the power factor is in the range of about 0.0002 to about 0.0005, and the dielectric constant is in the range of about 1.8 to about 2.4.

Abstract: The present invention relates to a process for the functionalization, and preferably the maleation of a polyolefin, preferably polypropylene, by use of a selected class of peroxides which will not cause the molecular weight of the polyolefin to significantly degrade. The class of peroxide initiators which are capable of successful use in the present invention may be more broadly classified as peroxides which have radical fragments when the peroxide is dissociated, which are a combination of R.multidot. and R0.multidot., where R is an aliphatic hydrocarbon, and 0 is oxygen. The preferred peroxide initiators for use in carrying out the present invention so as to obtain the results indicated above are t-butyl peroxypivalate and isononanoyl peroxide. The composition resulting from the practice of the process of the invention is a maleated polypropylene in which the polypropylene has more than 0.3 weight percent grafted maleic anhydride and preferably greater than 0.4 weight percent, for example, from 0.