화학공학소재연구정보센터
Polymer Engineering and Science, Vol.44, No.2, 223-230, 2004
Characterization of polyethylene terephthalate films drawn in hot water
Sorbed water molecules in PET (around 1% in mass) lead to classic plasticizing effects, basically evidenced by a decrease of the glass transition (T-g) and of the cold crystallization (T-c) temperatures with increasing water content. During drawing of dry PET film and depending on the draw ratio, the initial amorphous phase is oriented at first, and then a strain-induced crystallization appears. This work deals with the conjugate effects of drawing and water sorption in PET films drawn in hot water. Differential scanning calorimetry and birefringence measurements show that drawing performed in hot water leads to modifications of T-g and T-c without modification of the degree of crystallinity. Moreover, the formation of water clusters is observed when strain-induced crystalline phase occurs.