Acopolyester is acopolymer synthesized by modification ofpolyesters, which are combinations ofdiacids anddiols. For example, by introducing other diacids, such asisophthalic acid (IPA), or other diols, such ascyclohexane dimethanol (CHDM) to the polyesterpolyethylene terephthalate (PET), the material becomes a copolyester due to its comonomer content.[1]
Copolyesters retain their strength, clarity, and other mechanical properties even when exposed to a variety of chemicals that typically affect other materials, such aspolycarbonates. This, plus their versatility and flexibility, allows manufacturers to use them effectively in the design of both high-volume, low-cost parts as well as critical, more expensive component parts.
Copolyesters offer versatility to meet a wide variety of applications.[1]Copolyester resins have proved to be effective inpackaging applications, due to their toughness, versatility and chemical resistance. They are also frequently used in the manufacture and packaging ofconsumer goods and materials. Markets that rely on copolyesters include medical packaging,home appliances, consumer goods (pens, toys, sporting goods, etc.), andcosmetics, among others.[2][3][4][5][6]
Table of Common Copolyester and Components
| Polyester / Copolyester | Diacid (s) | Diol (s) | Properties |
|---|---|---|---|
| PET | Terephthalic acid (TPA) | Ethylene glycol (EG) | |
| PCTG | TPA | Cyclohexanedimethanol (CHDM)+EG | |
| PCTA | TPA +isophthalic acid (IPA) | CHDM | |
| PETG | TPA | CHDM+EG | |
| PCT | TPA | CHDM |
The main global manufacturers and suppliers of Copolyester resins are as follows (The brand names are in parentheses):