Condensation polymerization, titanate

Poly(butylenes terephthalate), often abbreviated to PBT or PBTP, is manufactured by condensation polymerization of dimethyl terephthalate and butane-1,4-diol in the presence of tetrabutyl titanate. The polymer is also known as poly(tetramethylene terephthalate), PTMT in short. Some trade names for this engineering thermoplastic are Tenite PTMT (Eastman Kodak), Valox (General Electric), Celanex (Celanese) in America and Arnite PBTP (Akzo), Ultradur (BASF), Pocan (Bayer), and Crastin (Ciba-Geigy) in Europe. 

The synthesis of terpoly(ester-6-ether-6-amide)s is a four-step process (Scheme 2) [12,17-20]. The second, third and fourth step take place in the presence of a magnesium titanate organometallic complex as a catalyst (10 wt% solution in n-butanol). The first step involves a hydroljdic condensation polymerization (the pressure decreases from 0.8-1.5 MPa to 0.1 MPa, at 280-320°C for 6-10 h) in the presence of sebacic acid as a stabilizer of the molecular weight. 

---