The effect of mechanical recycling on the microstructure and properties of PA66 composites reinforced with carbon fibers

Core-shell structured bamboo-plastic composites (BPCs) were directly prepared with a single-screw/single-screw coextruder system. The effects of different shell layers, such as high-density polyethylene (HDPE), bamboo pulp fiber (BPF)/HDPE, and white mud (WM)/HDPE, were studied in the context of the mechanical properties and the characteristics of the interfacial transition zone (ITZ) of BPC. The mechanical properties of the core-shell structured BPC were characterized by flexure, short-beam shear, and impact tests. The surface morphologies of BPC were analyzed with field emission scanning electron microscopy. The ITZ properties were studied with dynamic mechanical analysis and nano-indentation testing. The results show that the flexural properties, shortbeam strength, and impact strength decreased profoundly in the presence of BPF or WM. The dynamic mechanical analysis results suggest that the ITZ properties decreased, as indicated by the reductions in the storage modulus, loss modulus, and loss factor; the nano-indentation results show that on the addition of BPF or WM, a gradient in the hardness and modulus of elasticity appeared across ITZ.

Section: Resultssupporting

confidence: 94%

Understanding the mechanical and interfacial properties of core–shell structured bamboo–plastic composites

Yu¹,

Wang

Wang³

et al. 2015

“…Different polymers and nanofillers (metal, metal oxide, glasses, semiconductor) nanocomposites have been developed. A novel class of micro and nanofillers are represented by the carbon‐based nanoparticles, such as carbon nanotubes, carbon fibers, and most recently graphene and graphene‐like nanoplatelets (GNPs) …”

Section: Introductionmentioning

confidence: 99%

“…These three thermoplastic matrices were selected because of their wide range of application fields, due to their relatively low cost, high processability, good final mechanical and lower environmental impact with respect to all the other composites based on thermosets …”

Section: Introductionmentioning

confidence: 99%

Thermal behavior of thermoplastic polymer nanocomposites containing graphene nanoplatelets

Caradonna

Colucci

Giorcelli

et al. 2017

Self Cite

Polypropylene (PP), acrylonitrile butadiene styrene (ABS), and thermoplastic polyurethane (TPU) nanocomposites filled with 5 wt % of two different kinds of commercially available graphene nanoplatelets (GNPs) were prepared. Composites materials were characterized in terms of thermal properties (thermal conductivity and thermal stability) in order to study the effect of different fillers within different thermoplastic matrices. The exfoliation process and the mechanical properties were also investigated. We chose three different thermoplastic polymers (polyolefin, copolymer and elastomer) to cover a wide range of thermoplastic materials and identify a guideline in the use of GNPs for nanocomposite materials. No drastic differences were observed in terms of mechanical properties when the same matrices were filled with different GNPs. Concerning thermal conductivity, it was observed that the GNPs plane dimensions play a crucial role in the increase of conductive properties. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44814.

“…However, the crystallinities for LGF‐PA66 annealed at different temperatures are similar in this work, which indicates that the annealing treatment within studied temperatures has no significant effect on the crystallinity and characteristic temperature. According to previous studies, the crystallinity of PA66 generally ranges from 25% to 45%, hence the DSC results can be explained that the degrees of crystallinity for the specimens investigated were already at a relative high level before annealing. Furthermore, high‐content long glass fibers would restrict the movement of chain segments, and limit the arrangement of chain segments from amorphous region into crystalline region during annealing treatment.…”

Section: Resultsmentioning

confidence: 99%

Annealing effect on crystalline structure and mechanical properties in long glass fiber reinforced polyamide 66

Meng

Luo

et al. 2017

Generally, annealing is one of the important post-processing methods used to obtain injection molding products coupled with excellent comprehensive performance. Based on a series of experimental studies in this work, a systematic investigation was performed to research the annealing effect on crystalline structure and mechanical properties in long glass fiber reinforced polyamide 66 (LGF-PA66) composite. The composite was prepared by injection molding, using LGF-PA66 pellet with 50 wt % fiber content and 12 mm length. Composite samples were annealed in 120 8C to 200 8C range and then subjected to various tests at room temperature. Besides, the releasing strain during a specific temperature cycle was also investigated. Our results suggest that annealing treatment had a neglected impact on the crystallinity and crystal morphology of LGF-PA66 composite. However, with the increasing of processing temperature, annealing could strikingly promote the phase transition from g to a and the further growth of a 2 crystal in (010)/(110). In addition, annealing of LGF-PA66 composite resulted in a drastic increase in tensile and flexural properties and a reduction in impact strength, along with the transition of failure mode. The changes in mechanical properties were attributed to the crystal transition, strengthening of matrix performance, and the release of residual stress.