Tetramethylene terephthalate fibers

Poly(butylene terephthalate) is usually called PBT by analogy with PET, the well known fiber forming thermoplastic polyester. Like PET, PBT Is a linear condensation polymer based on tere-phthallc acid,, but Instead pf the ethylene glycol used in PET, PBT employs 1,4-butanedlol. ] The more definitive name, poly (tetramethylene terephthalate) or PTMT, never did catch on, perhaps an Indication of the power of three letter strings In the English alphabet. 

This polymer, with a very high melting point (265°C) and a good resistance to hydrolysis, has since been widely studied because of its commercial applications as a fiber (10). Recently, another polymer of the series, poly(tetramethylene terephthalate) = poly (butylene terephthalate) = 4GT, has been used as a thermoplastic resin (11)... 

Linear aliphatic chols are widely used as raw materials for polymers. Polymers synthesized from even-carbon diols tend to show excellent polymer properties. 1,4-Butanediol is very important as raw material for various polymers such as urethanes and polybutylene terephthalate (PBT), which is an engineering plastic. Since Celanese Corporation described a PBT resin in 1970, the demand for PBT resin, which is mainly used for automotive, electrical, and electronic equipment parts, has been expanding rapidly [1]. THF is also a major 1,4-butanediol derivative as a raw material for poly(tetramethylene ether) glycol used for artificial leather and elastic fibers in addition to being a high-performance solvent. Significant growth in demand for these 1,4-butanediol derivatives is expected in Asia, primarily in China. 

Five different kinds of fibers were used for the study. Cotton fiber is the base fiber, and four types of binder fibers, ordinary cellulose acetate (OCA), plasticized cellulose acetate (PCA), Eastar Bio copolyester unicomponent (Eastar), and Eastar Bio copolyester bicomponent (Eastar/PP) fibers. The chemical name of Eastar Bio copolyester is poly(tetramethylene adipate-co-terephthalate) (PTAT). The cotton fiber used in this research as the carrier fiber was supplied by Cotton Incorporated, Cary, NC. The scoured and bleached commodity cotton fiber had a moisture content of 5.2%, a micronaire value of 5.4 and an upper-half-mean fiber length of 24.4 mm. Both the OCA and PCA binder fibers were provided by Celanese Corporation, Charlotte, NC while the Eastar and Eastar/PP bicomponent binder fibers selected for this study were produced by Eastman Chemical Company, Kingsport, TN. The plasticizer used in PCA binder fiber is triethyl citrate ester (C12H20O7) with a weight concentration around 2%. The bicomponent Eastar/PP has a sheath core structure with Eastar as the sheath and PP as the core. The properties of these selected fibers are listed in Table 10.3. 

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