| 摘要 |
PURPOSE:To enhance selective permeability without damaging strength of membrane and membrane productivity by cooling down rapidly the macromole, in glassy state under room temperature, from the temperature more than the glass transition point down to 50 deg.C below the glass transition point. CONSTITUTION:The macromole, in glassy state under room temperature, such as polystyrene, polymethyl methacrylate, and cellulose acetate, is used. The higher glass transition point the macromole is carrying, the more remarkably the performance of membrane is enhanced. First, the macromole is turned into rubber-like in the temperature more than the glass transit point. The said temperature is preferably higher as far as the temperature is below the decomposition temperature for the macromole. After leaving the macromole in the said temperature for several hours, the same is stretched over in the form of membrane and then cooled down rapidly to low temperature. Since the bigger the temperature difference is, the better the results are, cooling down to as low as 50 deg.C below the glass transition point is preferable. With the cooling speed more than 50 deg.C/min., the macromole is dipped in the low temperature bath or sprayed with the cooling gas. |
