| abstract |
PURPOSE: A water-containing poor solvent is added to a polyphenylene oxide (PPO) solution, thereby preventing the formation of fine particles and recovering PPO with high bulk density (over 0.28 g/cc). n CONSTITUTION: To a solution of PPO of the formula (R 1 is H, alkyl, alkoxy, haloalkyl, haloalkoxy; R 2 , R 3 , R 4 are halogens, R 1 ; n is 50 or more) in a good solvent (the concentration is about 25 wt.% or lower, preferably 5W18 wt.%) is added a mixture consisting of a poor solvent for PPO as lower alkyl alcohol, alkyl ketone, and water to deposit PPO. When an aromatic solvent as toluene is used as a good solvent and methanol is used as a poor solvent, the weight ratio of the good solvent to the poor solvent is 1/1.1W2, the weight ratio of the poor solvent to water is 1/1W0.01, wherein the mixture forms one phase, and the precipitation temperature is 20W50°C. n COPYRIGHT: (C)1979,JPO&Japio |