Thermal Characterization of Non-Functionalized Low Content Graphene Nanoplatelets (GNP) Added Nylon 66 Polymer

Thermal behaviour of graphene nanoplatelets (GNP) reinforced nylon 66 nanocomposites were investigated using differential calorimetric scanning (DSC), thermogravimetric analyzer (TGA) and dynamic mechanical analysis (DMA). The influence of low content GNP on thermal properties of GNP/nylon 66 nanocomposites was studied for low GNP content (0.3, 0.5 and 1.0 wt%). DSC results indicate that addition of GNP increases crystallization temperature and degree of crystallinity of the nanocomposites. Thermal stability and mass loss were studied through TGA analysis. The results show that thermal stability and weight loss of GNP/nylon 66 nanocomposites slightly improve with the GNP addition with an increase in the onset of degradation temperature as much as 10 °C. DMA analysis shows that GNP in the nylon 66 matrix act similar to plasticizer; it decreases the storage modulus and glass transition temperatures of the nanocomposites. GNP addition also reduces tan δ indicating an improvement in the damping property of the nanocomposites. Overall, this study concludes that a minimal amount of 0.3 wt% of GNP is effective in improving the thermal properties of nylon 66 composites.

Application of Solution Blow Spinning for Rapid Fabrication of Gelatin/Nylon 66 Nanofibrous Film

Gelatin (GA) is a natural protein widely used in food packaging, but its fabricated fibrous film has the defects of a high tendency to swell and inferior mechanical properties. In this work, a novel spinning technique, solution blow spinning (SBS), was used for the rapid fabrication of nanofiber materials; meanwhile, nylon 66 (PA66) was used to improve the mechanical properties and the ability to resist dissolution of gelatin films. Morphology observations show that GA/PA66 composite films had nano-diameter from 172.3 to 322.1 nm. Fourier transform infrared spectroscopy and X-ray indicate that GA and PA66 had strong interaction by hydrogen bonding. Mechanical tests show the elongation at break of the composite film increased substantially from 7.98% to 30.36%, and the tensile strength of the composite film increased from 0.03 MPa up to 1.42 MPa, which indicate that the composite films had the highest mechanical strength. Water vapor permeability analysis shows lower water vapor permeability of 9.93 g mm/m2 h kPa, indicates that GA/PA66 film’s water vapor barrier performance was improved. Solvent resistance analysis indicates that PA66 could effectively improve the ability of GA to resist dissolution. This work indicates that SBS has great promise for rapid preparation of nanofibrous film for food packaging, and PA66 can be applied to the modification of gelatin film.

Effect of Powder on Tribological and Electrochemical Properties of Nylon 66 and Ultra-High Molecular Weight Polyethylene in Water and Seawater Environments

Polymer materials are used increasingly in marine machinery and equipment; their tribological properties and effect on the water environment have garnered significant attention. We investigate the effect of water or seawater environment containing powder on tribology and electrochemistry of polymer materials. A friction test involving nylon 66 (PA66) and an ultrahigh molecular weight polyethylene (UHMWPE) pin–disc (aluminum alloy) is performed in seawater or water with/without polymer powder, and the solution is analyzed electrochemically. The results show that the tribological properties of the UHMWPE improved by adding the powder to the solution, whereas the PA66 powder demonstrates abrasive wear in a pure water environment, which elucidates that the synergistic effect of powder and seawater on UHMWPE reduces the wear, and the synergistic effect of pure water and powder aggravates the wear. The results of electrochemical experiments show that after adding powder in the friction and wear tests, the powder can protect the pin by forming a physical barrier on the surface and reducing corrosion, and the changes are more obvious in seawater with powder in it. Through electrochemical and tribological experiments, the synergistic effect of solution environment and powder was proved.

Fabrication and Characterization of Nylon 66/PAN Nanofibrous Film Used as Separator of Lithium-Ion Battery

In recent years, portable electronic devices have flourished, and the safety of lithium batteries has received increasing attention. In this study, nanofibers were prepared by electrospinning using different ratios of nylon 66/polyacrylonitrile (PAN), and their properties were studied and compared with commercial PP separators. The experimental results show that the addition of PAN in nylon 66/PAN nanofibrous film used as separator of lithium-ion battery can enhance the porosity up to 85%. There is also no significant shrinkage in the shrinkage test, and the thermal dimensional stability is good. When the Li/LiFePO4 lithium battery is prepared by nylon 66/PAN nanofibrous film used as separator, the capacitor can be maintained at 140 mAhg−1 after 20 cycles at 0.1 C, and the coulombic efficiency is still maintained at 99%, which has excellent electrochemical performance.

Enhancing the properties of nylon 66 fabric coated with a combination of PVA and SiO2 nanoparticles composite for vehicle airbag application

Due to increase in fabric thickness and decrease compactness in packing, film bonding is unfavorable for airbag fabrics, furthermore, the uncoated fabric fabricated with a high density but it still has hot gas leakage problems. This study focuses on enhancement of vehicle airbag nylon 66 fabric properties by using a combination of different concentration of silica nanoparticles (SiO2 NPs) and low-density adhesion polyvinyl alcohol (PVA). The results illustrated that the nylon 66 fabric, which coated with PVA and SiO2 NPs presents an excellent property such as a thin layer reached at (0.009 mm), also thermal and mechanical properties have been enhanced to include better mechanical properties according to commercial guidelines airbag of Federal Motor Vehicle Safety Standards (FMVSS). Additionally, the weight per square meter of nylon 66 fabric coated with the PVA and high concentration of SiO2 NPs is 9.9 grams. Besides, the final dry weight of the coating (PVA/SiO2) material taken by the nylon 66 fabric is just 0.4 grams per square meter. The coated fabric demonstrated a hydrophobicity property in addition to the air-permeability has decreased by increasing the amount of SiO2 NPs in the composite material. The PVA and SiO2 NPs dispersed on the surface of the fabrics without any aggregation, as well, the coated fabric is gradually changed from flexible to hard which resulted in the better final performance in the proper and regular thickness along the whole fabric.

Development of Polymeric Membranes for Oil/Water Separation

In this work, the treatment of oily wastewater was investigated using developed cellulose acetate (CA) membranes blended with Nylon 66. Membrane characterization and permeation results in terms of oil rejection and flux were compared with a commercial CA membrane. The solution casting method was used to fabricate membranes composed of CA and Nylon 66. Scanning Electron Microscopy (SEM) analysis was done to examine the surface morphology of the membrane as well as the influence of solvent on the overall structure of the developed membranes. Mechanical and thermal properties of developed blended membranes and a commercial membrane were examined by thermogravimetric analysis (TGA) and universal (tensile) testing machine (UTM). Membrane characterizations revealed that the thermal and mechanical properties of the fabricated blended membranes better than those of the commercial membrane. Membrane fluxes and rejection of oil as a function of Nylon 66 compositions and transmembrane pressure were measured. Experimental results revealed that the synthetic membrane (composed of 2% Nylon 66 and Dimethyl Sulfoxide (DMSO) as a solvent) gave a permeate flux of 33 L/m2h and an oil rejection of around 90%, whereas the commercial membrane showed a permeate flux of 22 L/m2h and an oil rejection of 70%.

Tunable Selectivity of Phenol Hydrogenation to Cyclohexane or Cyclohexanol by Solvent-Driven effect over Bifunctional Pd/NaY Catalyst

Hydrogenation of phenol is an important strategy to produce cyclohexane or cyclohexanol as both of them are raw materials for the synthesis of nylon-6 and nylon-66. Herein, we report a...