NEW GENERATION OF CORROSION-RESISTANT POLYESTERS BASED ON TMPD GLYCOL.

This paper is concerned with the use of unsaturated polyester resins in the corrosion-resistant equipment industry. So far about 58 percent of this market is made up of the relatively low-cost, general-purpose corrosion-resistant resins produced from propylene glycol (PG), isophthalic acid (IPA) and maleic anhydride (MA). The balance is made up of premium-quality resins of which bisphenol A resins and vinyl ester formulations are most prominent. Newly formulated, unsaturated lower-density polyester resins based on 2,2,4-trimethyl-1,3-pentanediol glycol (TMPD**a glycol) with isophthalic acid or dimethyl terephthalate (DMT) exhibit better corrosion resistance than general-purpose isophthalic (IPA) resins. In addition, these newer resins are potentially more economical than premium-quality, corrosion-resistant polyesters. The formulas, cook procedures, cure characteristics, physical properties, corrosion resistance properties, and economics of resins based on TMPD glycol/PG/IPA and TMPD glycol/PG/DMT are discussed in comparison with general-purpose and premium-quality corrosion-resistant resins. Property data are tabulated and evaluated.