CHDM-based polyesters

This report provides an overview of some of the newer polyester compositions based on CHDM. The basic properties and chemistries of PCT have been described in earlier reviews [9, 13]. The CHDM-based polyesters covered in this review are PCT, PCTG, PCTA, and PETG. These compositions are described in more detail in the sections that follow. 

The following definitions have been traditionally used in the trade to describe the range of CHDM-based polyester compositions ... 

PET modified with up to 50 mol% CHDM is referred to as PETG. This resin is by far the most widely used of the CHDM-based polyesters. 

MODIFICATION OF CHDM-BASED POLYESTERS WITH OTHER GLYCOLS AND ACIDS... 

Although the scope of this review mainly covers CHDM-based polyesters modified with isophthalic acid or ethylene glycol (i.e. PCTA or PCTG, and PETG, respectively), many other copolyesters with interesting properties have been prepared with a variety of other comonomers. 

The selection of monomers for preparation of copolyesters is based on applying established structure/property principles and is usually driven by new market needs and applications with specific end-use properties in mind. Thus, attempts to develop amorphous or semicrystalline CHDM-based polyester compositions for applications requiring greater heat resistance or higher heat deflection temperatures have generally followed the theme of incorporating bulky or rigid constituents to further enhance the desirable thermal properties of CHDM-based... 

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