Polytrimethylene terephthalate

Polytrimethylene terephthalate, or PTT, is a polymer synthesized and patented in 1941. It is produced by a method called condensation polymerization or transesterification. The two monomer units used in producing this polymer are: 1,3-propanediol and terephthalic acid or dimethyl terephthalate. Similar to polyethylene terephthalate, the PTT is used to make carpet fibers.

PTT's value as a commercial polymer has improved lately, with the development of more economical and efficient methods to produce 1,3-propanediol (PDO) via continuous hydroformylation of ethylene oxide. DuPont is currently experimenting with the synthesis of PDO via bioplastic routes, i.e. using corn as the base material for PDO production. These developments may allow PTT to effectively compete against PBT and PET, two polyesters that have been far more successful than PTT to date.

On Friday, March 20th 2009, the Federal Trade Commission approved a subclass to traditional polyester called triexta. The PTT fiber that is currently used in Mohawk's SmartStrand carpet as well as Dupont uses with their brand Sorona, can now be labeled triexta. This is a departure from PTT being classified as traditional polyester, even though triexta will be a subclass to Polyester.

The FTC last approved an extension for residential carpet in 1959. The process of getting the FTC to approve the triexta polyester subclass was a joint effort between Mohawk Industries and DuPont. The process started back in 2006 and took nearly 3 years to be approved.

For years the carpet industry has dealt with the negative consumer perceptions of polyester carpet.

External links

• Forensic Science Communications literature review of Polytrimethylene terepthalate