Assessment of nanoparticle emission of polypropylene, polyester and epoxy nanocomposites during automated drilling process.

Polymer nanocomposites are becoming established widely across the industry due to (among other reasons) their lightweight performance advantages, and ability to meticulously target material properties with great control and precision. Despite the beneficial properties, certain nanofillers have shown potential health risks and toxicity, to both humans and the environment. The use and introduction of these materials into the workplace may therefore be hazardous if it involves human exposure. Research has yet to evaluate or quantify either the risk, the process of potential exposure, or the impact of embedded nanoparticles in commercial composites when they are released during machining processes. In this thesis, four groups of nanocomposites are identified as being used within industry and having potentially-harmful nanoparticles - the nanocomposites incorporate seven different nanoparticles of relevance, at different weight concentrations. This study involved the manufacture of the materials and an investigation into their effect on mechanical properties, through various methods: tensile tests, three-point bend flexural tests, SEM, EDX and FT-IR. The study employed a process approach for the assessment of nanoparticle emissions, using an automated drilling methodology in which the background noise was eliminated from the measurements. The investigation used real-time measurements with a combination of a condensation particle counter (CPC), a scanning mobility particle sizer spectrometer (SMPS), a real-time fast-mobility particle spectrometer (DMSSO) and post-test analytical methods. The research investigated the influence of a variety of nanofillers on nanoparticle release during drilling, from three different polymers: polyester (PE), polypropylene (PP) and epoxy (EP). Suitable fillers were tested for each polymer and demonstrated modifications to the material properties. The four sets of nanocomposites included PP-based, PE-based, EP-based and a hybrid EP/carbon fi