Studies of polymer electrets. I. Factors governing the stabilities of homoelectrets obtained from poly(1‐olefin)s

Various poly(1‐olefin)s have been studied as homoelectrets and their stabilities under different environmental conditions have been determined. It has been found that the stabilities of the homoelectrets, prepared from these polymers, depend on their volume resistivities, degrees of crystallinity, and the temperatures at which the crystalline domains of these polymers undergo transitional motions. Excellent stabilities have been exhibited by the homoelectrets prepared from poly(3‐methyl‐1‐butene), poly(4‐methyl‐1‐pentene) and other similar isotactic poly(1‐olefin)s with pendant branched side chains. It is postulated that the charged particles are trapped at the crystalline/amorphous interfaces in these polymers and the bulky alkyl substituents stabilize the charged particles by raising the transition temperatures of these polymers as well as by providing some additional chemical interaction sites.