Development of water soluble PBT and superfine fibers thereof

The water-soluble polybutylene terephthalate(WSPBT) was prepared through adding other modified monomers when synthesizing the polybutylene terephthalate(PBT).FTIR analysis was used to characterize the sample of WSPET and the existence of sodium ethylene glycol isophthalate-5-sulfate(SIPE) in the macro-chain of the sample was confirmed.The X-ray test showed that the WSPBT crystallizes easily and has good thermal stability,as shown by thermo-gravimetric analysis(TGA).The island-in-sea fiber which composed with WSPBT and common PET was prepared through composite spinning process.The weight loss rate of the island-in-sea fiber was tested after being dissolved in the boiling water for 45 minutes,and relationship between the added amount of SIPE and the water solubility of WSPET was discussed.The experimental results revealed that this easily crystallized WSPBT has good spinnability and the sea parts of the fiber can dissolve easily in the boiling water.