Composites for Life

The usage of bio-fibres and recycled materials is a growing approach to address the ecological problems being faced today. Inspired by the guidelines defining the Waste for Life initiative, the present study reports new composite materials, based on the recycling of high-impact polystyrene, found, for instance in yogurt cups, and paper plastic laminates, deriving from disposable paper cups. Given their recycling incompatibility, paper plastic laminates are either dumped in landfills or incinerated after their first usage, threatening the environmental condition. Therefore, through the development of a new composite solution, the goal was to reduce this damaging environmental impact by providing a second life to both paper plastic laminates and high-impact polystyrene. Samples presented overall good mechanical properties, from which it is highlighted a Young’s Modulus of 1.75 GPa and a Tensile Strength of 21.2 MPa, encouraging the application of the present material to identified global obstacles.

Experimental and analytical model for the penetration and indentation prediction on BFRP laminates under low velocity impacts

Low velocity impact tests at different impact energies were performed on basalt fibre reinforced plastic laminates, varying laminate thickness, stacking sequence, support dimensions and indenter diameter. A previous modified analytical model for the prediction of the indentation as a function of the impact energy, valid for carbon and glass fibre reinforced plastic laminates, was applied: a different behaviour was observed denoting an other damage mechanisms of the basalt fibre laminates. About the prediction of the penetration energy, the previous model largely applied in the literature showing the importance of the total fibre content was adopted, and a good agreement between the theoretical predictions and the experimental results was found. In analysing previous experimental data, in comparison to those of carbon fibre reinforced plastics, higher impact energy was found to be necessary to penetrate the basalt laminates whereas the indentation depth at the same impact energy was lower. A larger number of tests were carried out to validate a preliminary work done by the authors.

Solvent Absorption and Dissolution Kinetics Modelling for the Chemical Recycling of Waste Plastic Laminates

The Philippines is expected to have an increase in consumption of waste plastic laminates known as sachets, composed of polyethylene (PE) and polyethylene terephthalate (PET) and used in various food and non-food consumer goods. The increase in demand of these sachets has led the country to become one of the top ocean polluters worldwide. Chemical recycling- specifically selective dissolution and reprecipitation- is seen as one viable option for the recovery of these polymers. In this study, the absorption and dissolution kinetics of D-limonene, a potential candidate solvent, in the two-layer (2LL) and three-layer (3LL) laminates were modelled and analyzed for the design of separation equipment to recovery PE. The absorption of limonene for both laminates was observed to initially follow Fickian diffusion, but plateaus when the dissolution rate becomes comparable with the solvent diffusion rate. The dissolution of the 3LL almost closely follows Fickian behavior, while 2LL initially follows Fickian behavior. Deviations from Fickian dissolution may be attributed to the difference in swelling behavior between the non-uniform solvent-polymer diffusion layer and the glassy polymer layer.