Project Description: Sustainability is an ongoing challenge within the composites sector, with natural fibres presenting a potential avenues for nations to utilise locally sourced material for structural applications, rather than having to source materials from abroad, which can be expensive both in terms of cost and emissions. The challenge with natural fibres when it comes to composite materials is that they have historically struggled to provide the same reinforcement performance as consistently as can be found when using either carbon or glass fibre. One of the reasons behind this is that the surface of said fibres traditionally does not like to bond or adhere to the polymer resin chemistries we use in most high-performance composite applications.

One property that natural fibres typically possess, which is better than that found in carbon and glass fibres, is their ability to absorb loads when placed under high impact loads. Carbon and glass fibre composites typically explosively delaminate when significantly impacted, which can produce dangerous sharp shrapnel that can cause further damage. Natural fibre reinforced composites have meanwhile been shown to fail slightly differently, producing larger chunks which pose less of a risk to passer bys. The fibre-matrix interface is known to play a critical role in defining the material performance of the resulting composite. A poor interface likely will mean a poor final composite.

As such this project, in partnership with an industry partner, will look to explore how applying different surface treatments to wool fibres will impact their performance at the fibre-matrix interface level, and how that in terms will effect their impact performance. The project will be heavily experimental, and will be supported by multiple PhD students based within the Advanced Composites Group (ACG).

Project objectives: The key aims/objectives for the project will be as follows:

(i) Conduct a literature review into what surface treatments have traditionally be used in the past to improve the adhesion of wool fibres.

(ii) Apply different surface treatments to the wool fibres, and evaluate the effect of the stress transfer capability of the interface through use of the microbond test.

(iii) Utilise microscopy to analyse the effect (and quality) of the surface treatment(s) applied to the fibres, as well as evaluate the failure mechanics of the tested microbond samples.