Apparatus for effecting the depolymerization of polymeric esters

摘要

Apparatus adapted to be used for the depolymerization of polymeric esters and the production of a monomeric ester from the corresponding polymeric ester comprises a vat adapted to contain a bath of heated liquid, a cage for accommodating in fragmented form the substance to be depolymerized, a bell adapted to fit over the cage, and a condenser, wherein the cage has its lower part adapted to be immersed in the liquid and formed with one or more openings for the entry into it of the liquid, wherein the cage is formed around its lower part with an outwardly-projecting ring forming a gutter in which the lower edge of the bell engages beneath the surface of the liquid, the bell having an outlet in its upper part which is connected with the condenser in which the vapour produced by the depolymerization is condensed. In the Figure the apparatus comprises a vat 1 containing the bath liquid 2 and a bell 3 communicating at its upper part 3a with a condenser 5. The lower part of the side wall 3b of the bell is immersed in the bath liquid. Under the bell there is enclosed a cylindrical cage 4, the top of which is preferably open, the base 4a and the side wall 4b of the cage being made of perforated sheet metal. The base 4a of the cage is extended outwardly and upwardly so as to form an annular gutter 4c in which the wall 3b of the bell 3 engages. The lower edge of the bell 3 and the circular gutter 4c provide, with the liquid bath, an hydraulic joint which prevents the escape of the vapour produced under the bell. A pyrometer 6 and a galvanometer 7 are provided for use in controlling the bath temperature. In the example a polymer of methyl methacrylate is depolymerized using the apparatus claimed.