An oilfield element or assembly having a polymeric substrate protected by a polymeric coating adhered to at least a portion of the polymeric substrate. The coating includes a polymer having the formula --[R(R.sup.1.sub.x)(R.sup.2.sub.y)]--, wherein: R is selected from C--C, aryl, or --C(R.sup.3.sub.p)(R.sup.4.sub.q)-aryl-C(R.sup.5.sub.r)(R.sup.6.- sub.s)--; R.sup.1 and R.sup.2 may be the same or different; R.sup.3, R.sup.4, R.sup.5, and R.sup.6 are independently selected from halogen atoms and hydrogen atoms; and n is an integer ranging from 10 to 10,000.