Polybutylene

Polybutylene (polybutene-1, poly(1-butene), PB-1) is a polyolefin or saturated polymer with the chemical formula (C4H8)n.
Polybutylene is a form of plastic resin that was used extensively in the manufacture of water supply piping from 1978 until 1995. Due to the low cost of the material and ease of installation, polybutylene piping systems were viewed as "the pipe of the future" and were used as a substitute for traditional copper piping.
Polybutene consumption is most influenced by the market for fuel and oil additives, which in turn, is a function of lubricant sales. Lubricant sales in the US are growing at slightly better than 1%/year.