복합 금속염 및 이들의 조성이 Poly(1-oxotrimethylene)의 용해특성에 미치는 영향

Abstract

본 연구에서는calcium chloride (CaCl2), zinc chloride (ZnCl2), 그리고 lithium chloride (LiCl) 수용액 및 이들의 조성이 poly(1-oxotrimethylene) (ECO) 의 용해특성에 미치는 영향을 고찰하였다. 이들 중 오직 ZnCl2만이염 농도 65 wt% 이상에서 ECO를 용해 시킬 수 있었다. ECO의 고유점도를 측정한 결과, ZnCl2가 ZnCl2에 CaCl2와 LiCl를 첨가한 혼합계 보다 더 높게 나타났다. 분자간 상호작용이 크게 작용하는 6 wt%에서부터는 ZnCl2가 단독으로 사용된 ECO용액의 점도가 급격하게 상승하였으며, 7 wt% 이상에서는 불균일한 용액을 형성하였다. 반면 ZnCl2에 CaCl2 와 LiCl을 첨가하여 만든 7wt%의 ECO 용액의 경우 균일성이 향상되었다. ECO의 용해공정에 대한 각 금속염의 역할을 규명하기 위하여 ZnCl2 단독으로 사용된 ECO수용액 과 CaCl2 및LiCl이 각각 첨가된 ECO수용액의 유변학적 거동을 확인하였다. ZnCl2를 단독으로 사용한 ECO수용액의 경우 ZnCl2에 CaCl2 및 LiCl를 각각 첨가한 ECO용액들보다 더 큰 동적 점도를 보였다. ECO의 농도가 증가함에 따라 ZnCl2수용액에서 ZnCl2에 CaCl2와 LiCl를 각기 첨가한 수용액계에서 보다 shear thinning이 더 낮은 전단속도에서 나타났다. 이 현상은 50oC에서 70oC로 온도가 증가함에 따라 더욱 뚜렷하게 나타났다. Cole-Cole plot의 기울기로 ECO 용액의 불균일성을 확인한 결과 ZnCl2에 LiCl만 사용한 용액의 경우에는 온도가 증가함에 따라 균일성이 증가하였으나 나머지 염의 조합에서는 뚜렷한 균일성의 변화가 관찰되지 않았다.|The effect of respective metal salts of calcium chloride (CaCl2), zinc chloride (ZnCl2), and lithium chloride (LiCl) and their composition on the dissolution process of poly (1-oxotrimethylene) (ECO) were investigated. Only ZnCl2 aqueous solution was able to dissolve ECO when the salt concentration was above 65 wt%. In the dilute concentration range, only ZnCl¬2 containing ECO aqueous solution exhibited higher intrinsic viscosity than the ECO solutions in the mixture of ZnCl2 with CaCl2 and LiCl aqueous solution. From 6 wt% of ECO solutions in which the intermolecular interaction is dominant, drastic increase of viscosity was observed in the ZnCl2 containing ECO solution and heterogeneous ECO solutions were formed over the concentration of 7 wt%. Meanwhile, in the 7 wt% ECO solutions containing CaCl2 and LiCl in addition to ZnCl2, the solutions became more homogeneous. In order to verify the role of the respective metal salts in the dissolution of ECO, the rheological behavior of aqueous ECO solution containing only ZnCl2 were compared with those of ECO solutions containing ZnCl2 with CaCl2 and LiCl, respectively. The ZnCl2 containing aqueous ECO solution showed higher dynamic viscosity than the ECO solutions containing ZnCl2with CaCl2 and LiCl. With increasing the ECO concentration, the ECO solution containing only ZnCl2 showed onset of shear thining behavior at lower frequency than did ECO solutions in ZnCl2 aqueous solutions containing either CaCl2or LiCl. This phenomenon became more prominent when the temperature increased from 50oC to 70oC. In the slope of Cole-Cole plot which verifies the heterogeneity of solutions, the aqueous ECO solution with only LiCl added to ZnCl2 exhibited an increase in homogeneity with increasing temperature and no distinctive changes were observed in the other salt mixtures; The effect of respective metal salts of calcium chloride (CaCl2), zinc chloride (ZnCl2), and lithium chloride (LiCl) and their composition on the dissolution process of poly (1-oxotrimethylene) (ECO) were investigated. Only ZnCl2 aqueous solution was able to dissolve ECO when the salt concentration was above 65 wt%. In the dilute concentration range, only ZnCl¬2 containing ECO aqueous solution exhibited higher intrinsic viscosity than the ECO solutions in the mixture of ZnCl2 with CaCl2 and LiCl aqueous solution. From 6 wt% of ECO solutions in which the intermolecular interaction is dominant, drastic increase of viscosity was observed in the ZnCl2 containing ECO solution and heterogeneous ECO solutions were formed over the concentration of 7 wt%. Meanwhile, in the 7 wt% ECO solutions containing CaCl2 and LiCl in addition to ZnCl2, the solutions became more homogeneous. In order to verify the role of the respective metal salts in the dissolution of ECO, the rheological behavior of aqueous ECO solution containing only ZnCl2 were compared with those of ECO solutions containing ZnCl2 with CaCl2 and LiCl, respectively. The ZnCl2 containing aqueous ECO solution showed higher dynamic viscosity than the ECO solutions containing ZnCl2with CaCl2 and LiCl. With increasing the ECO concentration, the ECO solution containing only ZnCl2 showed onset of shear thining behavior at lower frequency than did ECO solutions in ZnCl2 aqueous solutions containing either CaCl2or LiCl. This phenomenon became more prominent when the temperature increased from 50oC to 70oC. In the slope of Cole-Cole plot which verifies the heterogeneity of solutions, the aqueous ECO solution with only LiCl added to ZnCl2 exhibited an increase in homogeneity with increasing temperature and no distinctive changes were observed in the other salt mixtures