PhD studentships
Porous Poly(Methyl Methacrylate) – Synthesis, Characterisation and Control of Porosity
Porous poly(methyl methacrylate) (PMMA) is becoming the material of choice for manufacture of moulds used for slip-casting of ceramics artefacts. An aqueous suspension of the ceramics powder is poured into the porous mould and the water removed through the pores in the mould via application of high pressure (5–40 bar; 0.5–4.0 MPa) so that the ceramics particles are forced to the mould walls to form a consolidated layer. At the end of the production cycle, water is expelled from the mould either by heating to 60 °C or by means of compressed air before being used again. The process enables ceramics artefacts of good homogeneity to be produced with a wide range of complex geometries. Introduction of porous PMMA (replacing plaster of Paris) as the mould material in the 1970s revolutionised the industry, greatly improving the lifetime of moulds, facilitating use of high pressure for de-watering and enabling more consistent and faster production of ceramics artefacts.
The method by which the porous PMMA moulds are produced has remained relatively unchanged since their commercial introduction and involves free-radical polymerisation of a pourable mixture of pre-formed PMMA beads, methacrylate monomer, water and surfactant at room temperature. This produces moulds with open pores that typically have an average pore size of 5–20 microns and a pore volume of 30%. Existing public knowledge of these polymerisations resides principally in the patent literature, which suggests that the water helps to reduce volume contraction during polymerisation and that the pore size in the mould produced is dependent on the size, shape and structure of the PMMA beads, which need to be predominantly of size < 100 microns. Key requirements are high strength, consistent permeability, low shrinkage and a degree of elasticity.
Despite their commercial importance, porous PMMA materials used in ceramics production have received extremely little academic attention. The objective of this project is to establish, through systematic fundamental studies, the effects of surfactant type/level, PMMA bead size, and polymer molar mass and composition on interfacial tensions, polymerisation rheology, and the morphology, pore size and mechanical properties of porous PMMA materials. The aim is to provide a scientifically-based rationale for design of porous PMMA materials with well-defined properties. The research student will become experienced in a range of important methods of free-radical polymerisation and polymer characterisation, as well as in developing methodologies for characterisation of pore structure.
The 3-year project will be carried out in close collaboration with Lucite International, one of the world's largest acrylic polymer producers, who will provide scientific and technical input, and financial support. It is expected that the research student will carry out some of the project work in their laboratories.
Degree Type
3 year PhD
Eligibility
Minimum requirement is a 2(i) (or equivalent) honours degree in Chemistry, Materials Science or a related discipline
Funding
The Project will be funded by the EPSRC and Lucite International.
Full funding is available only for UK nationals. Other EC nationals can receive tuition fees only unless they have been resident in the UK for the previous three years, in which case they qualify for full funding including subsistence.
The successful applicant will receive an EPSRC PhD scholarship which will be topped up by a £4,000 subsistence stipend as part of the financial support of the project by Lucite International.
Start Date
1 October 2009
Application Deadline
12 June 2009
Reference
PhD/09/PAL/01
Supervisor Contact Details
For further information about the project, please contact:
Email: pete.lovell@manchester.ac.uk
Tel: +44 (0)161 3063568
Admissions Contact
Postgraduate Team, School of Materials
Email: pg-materials@manchester.ac.uk
Tel: +44 (0)161 306 4824
How to Apply
You can apply for postgraduate opportunities online quoting the project reference number.