Preparation of Specialty Elastomers by Continuous Reaction in a Cavity Transfer Mixer

The application of post-polymerisation modification provides op portunities to change the performance profile of established polymers and thus generate new types of specialty product. Such operations are typically carried out in a batch; however, there is increasing interest in the possibilities and flex ibility of an operation that may be offered by reactive processing. Such flexibil ity includes continuous production and just-in-time technologies; this paper reports on trials with the cavity transfer mixer (CTM) as a polymer modifica tion reactor.

The paper considers the basic design of the CTM and its potential advantages as a reactor; it describes an experimental arrangement for practical trials. This arrangement employs an extruder and a plunger pump both feeding an inde pendently driven 25 mm diameter CTM. The operation of this equipment is il lustrated with respect to the manufacture of established polymers and also to the opportunities for producing new types of material. The former case is covered by the maleation of EPR whilst the latter is illustrated by the produc tion of an organometallic rubber, in this example by the derivation of XNBR.

For both these products, brief characterisation details are supplied and aspects of their potential utility are considered.