Abstract

CORTERRA PTT is the Shell trademark name for the aromatic polyesters known as polytrimethylene terephthalate (PTT). CORTERRA PTT polymers are produced by the polycondensation reaction of purified terephthalic acid (PTA) and 1,3-propanediol (PDO). PTT competes with the other aromatic polyesters - polyethylene terephthalate (PET) and polybutylene terephthalate (PBT) - as well as with nylon. CORTERRA PT is used in:

• Fibres for carpet and textiles
• Non-woven fabrics

Other emerging applications, including monofilament, film and engineering thermoplastics (ETPs). PTT greatly reduces the amount of acrolein generated during thermal decomposition of the polymer. This stabilisation is effective at temperatures well above the melt temperature and is active for days at these temperatures. 

Introduction:

CORTERRA Polymer is aromatic polyester known generically as PTT, (polytrimethylene terephthalate). PTT is produced by the polycondensation reaction of PTA (purified terephthalic acid) and PDO (1,3-propanediol) and has unique properties as compared to the other aromatic polyesters, PET (polyethylene terephthalate) and PBT (polybutylene terephthalate).

The unique properties of PTT have been known for many years, but the polymer has not been commercially available because of the high cost of production of the PDO raw material. Extensive research efforts has resulted in a cost-effective process to manufacture PDO. With this breakthrough in processing technology for PDO, CORTERRA Polymers are now commercially available for use in carpet and textile fibers monofilament, film, nonwoven fabric, and engineering thermoplastic applications.

CORTERRA 200 can be used by itself, as the base polymer for compounds, or as a polymer modifier for many engineering thermoplastic applications. Compounded engineering resins based on CORTERRA PTT polymer provide physical properties that are equivalent to or better than those of similar PBT compounds. Extrusion and injection molding conditions, and processing characteristics are very similar to those established for PBT. PTT compounds generally exhibit higher tensile strength, flexural modulus and heat deflection temperatures but with slightly lower impact strength than the PBT counterparts.

Development of PTT Polymer:

CORTERRA Polymer is an aromatic polyester known generically as PTT, polytrimethylene terephthalate). PTT is produced by the polycondensation reaction of PTA (purified terephthalic acid) and PDO (1,3-propanediol) and has unique properties as compared to the other aromatic polyesters, PET (polyethylene terephthalate) and PBT (polybutylene terephthalate).

The unique properties of PTT have been known for many years, but the polymer has not been commercially available because of the high cost of production of the PDO raw material. Extensive research efforts by Shell Chemicals** has resulted in a cost-effective process to manufacture PDO. With this breakthrough in processing technology for PDO, CORTERRA Polymers are now commercially available for use in carpet and textile fibers monofilament, film, nonwoven fabric, and engineering thermoplastic applications.

CORTERRA 9240 is a semi-dull, PTT homopolymer. The polymer properties which provide resilience, elastic recovery, high bulk, soft hand, inherent stain resistance, and ease of dyeing, make it well-suited for carpet and textile fibers. CORTERRA 9240 has TiO₂ added as a dulling agent and is used when a bright or shiny luster is not desired in the end product.

Many of these same properties make CORTERRA 9240 a good candidate for nonwoven applications. CORTERRA 9240 can be compounded to provide performance properties and processing characteristics that are similar to PBT.