Caolan Jameson

Maleic anhydride (MAH) grafting is widely employed to compatibilise polylactic acid (PLA) in fibre-reinforced composites; however, the influence of reactant addition sequence during melt processing varies widely across the literature, with no clear consensus on an optimal approach. In this study, the effect of reactant addition sequence on the graft yield of MAH onto PLA was investigated using dicumyl peroxide (DCP) as an initiator. Four loading protocols were examined in which the order of addition of PLA, DCP, and MAH was varied using approaches commonly reported in the literature, while all other processing conditions were held constant. A strong dependence of grafting yield on addition sequence was observed, with values ranging from 0.12% to 0.51%, corresponding to more than a four-fold variation under otherwise identical processing conditions. Simultaneous addition of PLA, DCP, and MAH produced the highest grafting yield, attributed to a more effective utilisation of peroxide-derived radicals. These results demonstrate that the reactant addition sequence is a critical processing variable governing MAH grafting efficiency and that simultaneous addition represents the most effective processing strategy under the conditions examined.

Maleic anhydride (MAH) grafting is widely employed to compatibilise polylactic acid (PLA) in fibre-reinforced composites; however, the influence of reactant addition sequence during melt processing varies widely across the literature, with no clear consensus on an optimal approach. In this study, the effect of reactant addition sequence on the graft yield of MAH onto PLA was investigated using dicumyl peroxide (DCP) as an initiator. Four loading protocols were examined in which the order of addition of PLA, DCP, and MAH was varied using approaches commonly reported in the literature, while all other processing conditions were held constant. A strong dependence of grafting yield on addition sequence was observed, with values ranging from 0.12% to 0.51%, corresponding to more than a four-fold variation under otherwise identical processing conditions. Simultaneous addition of PLA, DCP, and MAH produced the highest grafting yield, attributed to a more effective utilisation of peroxide-derived radicals. These results demonstrate that reactant addition sequence is a critical processing variable governing MAH grafting efficiency.

Reusable packaging is a promising solution to reduce plastic waste and mitigate the negative environmental impact of single‐use plastics. Furthermore, incorporating recycled materials can further enhance sustainability by reintroducing end‐of‐life plastic waste into a circular system. Although repeated use conditions, such as microwave heating and dishwashing, have been shown to result in alterations in the material properties of packaging, limited research exists on how reuse may impact recycled grades. It remains unclear whether recycled materials are more susceptible to degradation due to the treatment conditions involved in their refurbishment. This study investigates the feasibility of using postindustrial recycled polypropylene (PIR PP) as an alternative to virgin PP in reusable food packaging, with a focus on functionality, material properties, and microbial safety. Virgin PP homopolymer, virgin PP copolymer, and PIR PP were subjected to a simulated reuse protocol involving oven heating and dishwashing for up to 20 cycles. Material characterization and microbiological testing revealed no loss of performance or compromise of microbial safety in any of the three materials. The findings suggest that PIR PP performs comparably to virgin PP under repeated use conditions, supporting its suitability for reusable packaging and contributing to the development of circular and sustainable packaging solutions.

This study explores the mechanical performance of polycarbonate (PC) and acrylonitrile butadiene styrene (ABS) filaments fabricated using fused filament fabrication (FFF), Arburg plastic freeforming (APF), and injection moulding (IM). A series of controlled experiments, including differential scanning calorimetry (DSC), scanning electron microscopy (SEM), dynamic mechanical thermal analysis (DMA), and mechanical tests, were conducted to evaluate the material’s mechanical, thermal, and chemical properties. The results highlight the influence of process parameters and material choice on the mechanical properties of PC/ABS components. The FFF samples exhibited the highest impact strength (up to 28.82 kJ/m²), attributed to porosity acting as a stress absorber under impact load. However, this same porosity led to a 9.14% and 19.27% reduction in flexural and tensile strength, respectively, compared to the APF samples, where stress concentration effects were more pronounced under flexural loads. APF’s mechanical properties were comparable to those of IM, with the process achieving the highest tensile strength, highlighting its potential for producing robust PC/ABS samples. This study aims to provide valuable insight into the selection of additive manufacturing (AM) processes for PC/ABS components.

This study investigates the effect of extrusion screw speed and carbon nanotube (CNT) concentration on the thermal, mechanical, and electromagnetic interference shielding effectiveness (EMI SE) properties of Polycarbonate (PC)/acrylonitrile-butadiene-styrene (ABS) and its polymer nanocomposites (PNCs) by means of design of experiments (DoE) approach. A masterbatch method was employed to obtain the best dispersion of the CNTs throughout the polymer matrix. This study evaluates the thermo-mechanical characterisation of the polymers and PNCs at varying screw speeds to assess filler matrix bonding. The results highlight that CNT concentration has a significant effect on all mechanical properties, while screw speed only affects the Charpy impact strength and flexural properties of the samples. Compounding at 200 rpm has the best flexural and tensile strength, which is attributed to the best filler matrix bonding (highest storage modulus) of the PNCs. The best EMI SE results were obtained at 10 wt.% CNTs. This research contributes valuable insights into the effect of CNT concentration and extrusion screw speed on the mechanical, thermal and EMI SE properties of PC/ABS and its PNCs.