Utilizing Upcycled Graphene Nanoplatelet-Coated Glass Fibers as a Performance Booster and Compatibilizer for Enhanced Mechanical Performance of Polypropylene/Glass Fiber/Graphene Nanoplatelet Composites.

The high usage ratio and elevated density of glass fibers (GFs), often surpassing twice that of polymers, can contribute to undesired increases in the overall density of polymeric materials. One potential solution is the incorporation of graphene as a secondary additive, offering a lower specific gravity and exceptional mechanical properties. In light of this, waste tire-derived graphene nanoplates (GNPs) were optimized for coating onto GFs by considering factors such as surface treatment of the fiber, the dispersion quality of GNP, and the coating technique. The resulting GNP-coated GF (GNP-c-GF) was initially incorporated into pure polypropylene (PP) at low weight percentages (0.1-1 wt %), and 31% increase in the tensile modulus was achieved compared to neat PP. Subsequently, 1 wt % GNP-c-GF was utilized as a compatibilizer in PP/GF/GNP composites to enhance the compatibility between GNP and GF. By strategically incorporating GNP and GNP-c-GF at a lower GF ratio, the detrimental impact on the tensile modulus of 30% GF-filled PP was effectively mitigated, leading to a remarkable enhancement to an impressive value of 5658 MPa. The successful integration of GNP and GNP-c-GF exemplifies their promising potential as additives for achieving superior mechanical properties in composite materials, while concurrently promoting the utilization of recycled content.

Sustainable Engineered Design and Scalable Manufacturing of Upcycled Graphene Reinforced Polylactic Acid/Polyurethane Blend Composites Having Shape Memory Behavior.

Material design in shape memory polymers (SMPs) carries significant importance in attaining high performance and adjusting the interface between additive and host polymer matrix to increase the degree of recovery. Herein, the main challenge is to enhance the interfacial interactions to provide reversibility during deformation. The present work describes a newly designed composite structure by manufacturing a high-degree biobased and thermally induced shape memory polylactic acid (PLA)/thermoplastic polyurethane (TPU) blend incorporated with graphene nanoplatelets obtained from waste tires. In this design, blending with TPU enhances flexibility, and adding GNP provides functionality in terms of mechanical and thermal properties by enhancing circularity and sustainability approaches. The present work provides a scalable compounding approach for industrial applications of GNP at high shear rates during the melt mixing of single/blend polymer matrices. By evaluating the mechanical performance of the PLA and TPU blend composite composition at a 9:1 weight percentage, the optimum GNP amount was defined as 0.5 wt%. The flexural strength of the developed composite structure was enhanced by 24% and the thermal conductivity by 15%. In addition, a 99.8% shape fixity ratio and a 99.58% recovery ratio were attained within 4 min, resulting in the spectacular enhancement of GNP attainment. This study provides an opportunity to understand the acting mechanism of upcycled GNP in improving composite formulations and to develop a new perspective on the sustainability of PLA/TPU blend composites with an increased biobased degree and shape memory behavior.