The production of polymer nanocomposites using intensified modules

The advent of a new generation of polymer nanocomposites in recent years has resulted in the emergence of substantially improved engineering and structural materials with enhanced mechanical properties. Such materials comprise a wide range of conventional homopolymers and filler materials such as treated clays, inorganic particulates, carbon nanotubes and glass fibres. To date, the focus of much of the literature has been on the conception and testing of new nanocomposites and their properties, particularly clay-based systems, and to a lesser extent particulates. However an efficient, continuous method of generating such materials has yet to be developed.

Process Intensification, (PI), is a strategy which entails the reduction of process volume without a decrease in product throughput. Its aim is to enhance mixing and improve mass and heat transfer rates and so optimise the conditions for effective chemical reactions. This should result in improved conversion and product quality, as well as reducing waste through improved selectivity.

Fig. 1 - Spinning Disc Reactor

Fig. 2 - Barium Sulphate Crystals (0.2 - 0.7 mm)

PI offers the potential to produce particulate-based nanocomposites in a continuous mode which optimises the necessary conditions for the three key processes of polymerisation, nanoparticle production and the effective mixing of the two composite elements of particle and polymer.

The Spinning Disc Reactor, SDR (Figure 1), has been employed for the synthesis of poly(methyl-methacrylate) by means of photo-initiation under ultra-violet light at 25°C. It can be operated as a one-pass reactor or used to recycle a polymerising mixture until the desired mass yield and molecular weight properties have been achieved. The aqueous production of particles to sizes of the order 0.1- 0.7 mm, (Figure 2), has also been indicated on SDR and spinning cone devices suggesting the possibility of an integrated reaction and mixing process where polymer and particle can be generated and inter-dispersed simultaneously. The development of such a process is the primary objective of this project.

The project has been in progress since November 2002 and is due for completion in February 2006. The principal sponsors are Protensive Ltd. and the Engineering Physical Sciences Research Council, (EPSRC). Additional collaborators include Drs. K.V.K. Boodhoo, (supervisor) and W.A. Dunk, (Protensive Ltd., Newcastle).

For more information please contact Dr Kamelia Boodhoo.