CEH Report

Table of Contents

Abstract

Unsaturated polyester resins are produced by the polycondensation of saturated and unsaturated dicarboxylic acids with glycols. Unsaturated polyester resins form highly durable structures and coatings when they are cross-linked with a vinylic reactive monomer, most commonly styrene. The properties of the cross-linked unsaturated polyester resins depend on the types of acids and glycols used and their relative proportions.

This report also covers vinyl ester resins, since the industry and government have chosen to group them with unsaturated polyester when collecting their statistics; however, vinyl esters are actually hybrids between unsaturated polyester and epoxies. They are linear reaction products of bisphenol A and epichlorohydrin that are terminated with an unsaturated (vinylic) acid such as methacrylic acid. This product is dissolved in styrene and is applied and cross-linked in the same way as unsaturated polyesters.

On their own, cross-linked unsaturated polyester and vinyl ester resins have limited structural integrity, so they are often combined with fiberglass or mineral fillers before cross-linking to enhance their mechanical strength. Resins combined with fiberglass are referred to as fiberglass-reinforced plastic (FRP). Both lightweight and durable, FRP composites are consumed primarily by the construction, marine and land transportation industries, although they find use in a variety of other applications. Nonreinforced cross-linked unsaturated polyester resin is used to make cultured marble and solid surface counter tops, gel coats, automotive repair putty and filler, and other items such as bowling balls and buttons.

The following pie chart shows world consumption of unsaturated polyester resins:

Sales in the primary end markets for unsaturated polyester resin—construction, automotive and marine—depend on the performance of the general economy and unsaturated polyester resin consumption tends to swing dramatically with any change in gross domestic product (GDP).

Future demand growth (2007–2012) in North America is forecast to slow somewhat especially in the United States. U.S. demand had a considerable drop in 2008, with a decline of 15–16% and will continue to decline in 2009.

Future demand growth (2007–2012) in Europe, the Middle East and Africa is forecast to slow somewhat. The industry will not be able to decouple from the financial crises, which reached the producing sector in 2008. In fact in 2008, demand was down, especially in the last quarter of 2008. Highest growth in the region is forecast for Russia, which will continue to grow at a double-digit rate, albeit from a small base. Future demand growth (2007–2012) in Asia is forecast to slow somewhat.

The most dynamic market for unsaturated polyester resins is wind energy. On a global basis, new installed wind energy capacity in 2007 was about 20 gigawatts (GW). For 2012, new installed capacity worldwide is forecast to grow to almost approximately 53 GW (or 18% per year). Unsaturated polyester resins (including vinyl ester) are used to produce rotor blades, engine housings and gel coats in competition with epoxy resins. In Western Europe, annual growth of 7–8% is forecast for unsaturated polyester resin consumption in this segment during 2007–2012. Growth will be higher in Asia.