Abstract: A molecular weight of a polymer is measured by a process including steps of: heating a polymer portion with a heating device, measuring, with a temperature measuring device, the difference between temperatures of at least two points of the polymer portion at each of which the polymer portion is subjected to a thermally different influence from each other by the heating device, and estimating the molecular weight of the polymer which corresponds to the difference between the temperatures obtained by the measuring step according to a relationship between the temperature difference and the molecular weight of the polymer which relationship has been beforehand obtained.

Abstract: A method for purifying a crude high-molecular weight substance containing an alkali metal compound by extracting the alkali metal compound with water is disclosed, which comprises stirring a mixture comprising said crude high-molecular weight substance and water in a high-speed stirring tank to extract the alkali metal compound into an aqueous phase and separating the high-molecular weight substance phase and the aqueous phase from each other by continuous centrifugation. An alkali metal compound as an impurity can be efficiently removed with small-sized equipment in a short time.

Abstract: A stirring reactor for a viscous material. The reactor comprises a stirring vessel; a revolvable shaft provided in the vessel; a surface layer stirring vane provided on the revolvable shaft in the vicinity of interface of the gas and the liquid to be stirred; a stirring vane having at least a pair of radially directed multiple portion blades which extend radially towards the inner wall, a first of which blade portions is fastened on the revolving shaft below the upper layer stirring vane and the other of which blade portions extends outwardly radially from said first portion to terminate close to the inner wall of the vessel; and baffle plates provided on the inner side wall at positions substantially parallel to the surface layer stirring vane, and at a height between the heights of any stirring vanes having multiple blades.

Abstract: A method for coagulating a latex of a synthetic polymer having a coagulated latex particle formation temperature to form substantially spherical particles, the method comprising: forming substantially spherical latex particles by dispersing substantially spherical drops of the latex into a vessel or chamber containing a coagulating atmosphere which can be (i) a gaseous coagulant or (ii) a liquid coagulant in the form of a mist of drops having diameters such that the terminal settling velocity of the drops under free-falling conditions is in accordance with Stokes' Law, while maintaining the coagulant at the coagulated latex particle formation temperature and while causing water at the coagulated latex particle formation temperature to flow downward over the inner surface of the coagulation vessel to cause pluralities of polymer particles in a drop of the latex to coagulate to form substantially spherical coagulated latex particles.