Recycling of thermoplastic composites

The use of continuous fibre reinforced thermoplastic composites (CFT) is growing in recent years. The major driver is the growing demand for thermoplastic composites in different industries due to its recycling potential. In spite of having many advantages, high melt viscosity of thermoplastic polymers poses a major limitation to the production of continuous fibre reinforced thermoplastic composites (TPCs). High processing temperatures and pressures are required to lower down the melt viscosity of the thermoplastic matrices to wet and impregnate the reinforcement fibres. The problem of high viscosity can be overcome by using low viscosity, monomeric liquid thermoplastic resin which polymerises in-situ during composite manufacturing via liquid resin infusion route. The manufacturing of continuous fibre reinforced thermoplastic composites via in-situ polymerisation route is thus becoming popular for structural applications as they offer both recyclability and easy manufacturability. However, the recycling routes of such thermoplastic composites need extensive research to understand how the properties can be retained to its maximum extent.

The project will investigate the recyclability of PA6/glass fibre composites produced by liquid resin transfer moulding of caprolactam monomer. The project work will be carried out in collaboration with an industrial partner who produces in-situ polymerised glass/PA6 composites for industrial applications.

Objectives: The overarching objectives of the project are:

  • Investigate the properties of PA6 matrix polymerised in-situ during composite manufacturing using caprolactam monomer. This will include determination of average molecular weight, molecular weight distribution and % crystallinity.
  • Compare in-situ polymerised PA6 matrix with commercially available PA6 polymers that are commonly used as matrix in composites.
  • Study the role of different fibre sizing agents on the properties of in-situ polymerised PA6 matrix and their effects on thermal degradation behaviour and thermal reprocessability of the composites.
  • Investigate the effect of thermal reprocessing on the matrix as well as on the composite properties, mechanical properties in particular.

The project will involve composite manufacturing by resin transfer moulding, composite testing and polymer characterisation. Various characterisation techniques will be used such as Gel permeation chromatography (GPC), NMR spectroscopy, Raman and FTIR spectroscopy, Dynamic mechanical analysis (DMA), Differential scanning calorimetry (DSC), Thermogravimetric analysis (TGA), mechanical testing and scanning electron microscopy.

Further Information: 

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Closing Date: 

Saturday, February 25, 2023

Principal Supervisor: 

Assistant Supervisor: 

Eligibility: 

Minimum entry qualification - an Honours degree at 2:1 or above (or International equivalent) in a relevant science or engineering discipline, possibly supported by an MSc Degree. Further information on English language requirements for EU/Overseas applicants.

Funding: 

Tuition fees and stipend are available for Home and potentially International students

Further information and other funding options.

Informal Enquiries: