Studies On The Dyeable Blended PET/PET-Copolyester Fiber

A series of poly(ethyleneterephthalate)(PET)/PET-copolyester polymer blends and fibers from these blends are preparated . The polymer blends are : PET/CDP(CDP: cation dye dyeable polyester or high pressure type cation dye dyeable polyester) ; PET/ECDP(easy cation dye dyeable polyester or normal pressure type cation dye dyeable polyester); PET/ECDP/polyethyleneglycol(PEG)and PET/CGP[CGP: PET-polybutylene-terephthalate(PBT)-polybutyleneglycol(PEG)copolyester]. The transition temperature, crystalline structure, rheological behavior and thermal stability were studied .The rusults show,the glass transition temperrature (Tg) of PET/CDP, PET/ECDP and PET/ CGP is decreased and the crystallizition rate is increased with increasing of temperature, and it reach the maxium when temperature is a certain value ,then it decreases with increasing of temperature . The apparent viscocity of polymer melt of PET/CDP and PET/ECDP is increased with the increasing of amount of CDPand ECDP added , the apparent viscocity of polymer melt of PET/CGP is decreased with the increasing of amount of CGP added. The Tg and apparent viscocity of PET/ECDP/PEG are all lower thanthat of PET50/ECDP50. In comparison with PET the thermal stability of all polymer blends is decreased .The dyeabiliy of blended fibers is markedly improved ; absorptive , and anti -static property of fibers are also improved.The mechanism of dyeing of blended fiber was studied , the size of microvoids of fiber was examined through equatorial small angle X-ray scattering method. The results show that dyeabiliy of blended fiber depends mainly upon Tg , crystallinity , crystalline size, size and quantity of microvoids of fibers. High speed spinning is favourable for increasing dyeability due to increasing of microvoid sizes of fibers. Dyeabiliy of PET/ CGP and PET/ECDP/PEG fiber is improved greatly, and these blend fiber have a good prospect of application.