ポリプロピレンとポリエチレンとの浮選分離について
1978 年 94 巻 1085 号 p. 475-478
詳細
1978 年 94 巻 1085 号 p. 475-478
Separation of Polypropylene (PP) from Polyethylene (PE) was studied by making use of an air lift type flotator in which the former was recovered as a float and the latter as a sink, respectively. Separation between PP and PE was achieved satisfactorily by employing polyvinylalcohol (PVA) of relatively low degree of polymerization, i.e. n=500, as a depressant for PE.
Flotation results were well correlated with contact angle measurements and adsorption study. Greater decrease in contact angle, i.e. from 62° to 28°, was found for PE in contact with PVA aqueous solutions in a concentration range from zero to 100mg/l as compared with PP-PVA system where contact angle changed from 84° to 65° under corresponding conditions. Adsorption amount of PVA on PE was always greater than that on PP over the concentration range studied. The latter tended to increase with increasing the degree of polymerization of PVA, making the PP surface hydrophilic. Thus, it is essential to use PVA of appropriate degree of polymerization in order to separate PP from PE.
