Industrial step-growth products, processes and modeling

3 Industrial step-growth products processes and modeling 

Poly(ethylene terephthalate), the lowest cost and most commonly used polyester, is produced using ethylene glycol (EG) and either dimethyl terephthalate (DMT) or terephthahc acid (TPA) (see Table 7.1). Processes using DMT were commercialized first, but when very pure TPA became available, TPA processes became more economical for large-scale fiber production. Poly(butylene terephthalate) (PBT), produced fi-om 1,4 butanediol and DMT, is another commercially important polyester, which is used for computer housings and many other molded products. Poly(trimethylene terephthalate) (PTT), made from TPA and 1,3 propanediol, is a relatively new commercial polyester, that shows promise for 

The two main commercial polyamides are nylon 6,6, produced by condensation polymerization of HMD and adipic acid (see Table 7.1), and nylon 6, an AB-type polymer, which is produced from caprolactam. Other commercial polyamides include nylons 4,6, nylon 6,12 (which are AA- and BB-type polymers) and nylon 11 and nylon 12 (which are AB polymers made from linear aliphatic amino acids containing 11 and 12 carbons, respectively) [1]. Polyamides are also produced using monomers with aromatic, rather than aliphatic segments. Polyamides that contain 85% or more of the amide bonds attached to aromatic rings are called aramids. Commercial examples include poly(p-phenyleneterephthalamide) or Kevlar and poly(m-phenyleneisoterephthalamide) or Nomex [23]. 

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