Studies on Recycling Silane Controllable Recovered Carbon Fiber from Waste CFRP

During the production process of commercial carbon fiber reinforced polymers (CFRPs), a silane coupling agent is added to the carbon fiber at the sizing step as a binder to enhance the product’s physical properties. While improving strength, the silane coupling agent results in a silane residue on recovered carbon fibers (rCF) after recycling, which is a disadvantage when using recovered carbon fibers in the manufacture of new materials. In this study, the rCF is recovered from waste carbon fiber reinforced polymers (CFRPs) from the bicycle industry by a microwave pyrolysis method, applying a short reaction time and in an air atmosphere. Moreover, the rCF are investigated for their surface morphologies and the elements present on the surface. The silicon element content changes with pyrolysis temperature were 0.4, 0.9, and 0.2%, respectively, at 450, 550, and 650 °C. Additionally, at 950 °C, silicon content can be reduced to 0.1 ± 0.05%. The uniformity of microwave pyrolysis recycle treatment was compared with traditional furnace techniques used for bulk waste treatment by applying the same temperature regime. This work provides evidence that microwave pyrolysis can be used as an alternative method for the production of rCFs for reuse applications.

Synthesis of Substrate-bound Seaweed-like Au Nanowires with Amino Silane Coupling Agents

Seaweed-like Au nanowires were synthesized without any nanoparticle seeds. The amino silcane coupling agent 3-aminopropyltriethoxysilane was used to form the active surface on Au substrate to facilitate one dimensional growth....

Effect of Coupling Agent on Softwood Kraft Nanocellulose Fibril-Reinforced Polylactic Acid Biocomposite

The nanocellulose fibril produced by using natural sources can be used in developing sustainable and green products. The useful features of nanocellulose fibril can include valuable physical properties, appropriate surface chemistry, low toxicity, and biocompatibility. The study presented shows the use of polylactic acid with five different percentages of nanocellulose fibril and the use of 3% maleic anhydride as a coupling agent. The maleic anhydride acts as coupling agent which improves the thermochemical and thermomechanical characteristics of the end product. The addition of 3% maleic anhydride as coupling agent with 10% nanocellulose fibril improved the impact strength up to 14.3%, elastic modulus up to 40.6%, and tensile strength up to 30.1%. Furthermore, the dynamic mechanical analysis result indicates that the inclusion of maleic anhydride improved the toughness by reducing the tan δ peak and increases the storage modulus. Finally, the scanning electron micrograph shows that the interfacial compatibility between nanocellulose fibril and polylactic acid matrix is improved with the addition of maleic anhydride.

Effects of Coupling Agent and Thermoplastic on the Interfacial Bond Strength and the Mechanical Properties of Oriented Wood Strand–Thermoplastic Composites

Wood–plastic composites (WPC) with good mechanical and physical properties are desirable products for manufacturers and customers, and interfacial bond strength is one of the most critical factors affecting WPC performance. To verify that a higher interfacial bond strength between wood and thermoplastics improves WPC performance, wood veneer–thermoplastic composites (VPC) and oriented strand–thermoplastic composites (OSPC) were fabricated using hot pressing. The effects of the coupling agent (KH550 or MDI) and the thermoplastic (LDPE, HDPE, PP, or PVC) on the interfacial bond strength of VPC, and the mechanical and physical properties of OSPC, were investigated. The results showed that coupling agents KH550 and MDI improved the interfacial bond strength between wood and thermoplastics under dry conditions. MDI was better than KH550 at improving the interfacial bond strength and the mechanical properties of OSPC. Better interfacial bonding between plastic and wood improved the OSPC performance. The OSPC fabricated using PVC film as the thermoplastic and MDI as the coupling agent displayed the highest mechanical properties, with a modulus of rupture of 91.9 MPa, a modulus of elasticity of 10.9 GPa, and a thickness swelling of 2.4%. PVC and MDI are recommended to fabricate WPCs with desirable performance for general applications.

Membrane Distillation: Pre-Treatment Effects on Fouling Dynamics

In the research reported in this paper, membrane distillation was employed to recover water from a concentrated saline petrochemical effluent. According to the results, the use of membrane distillation is technically feasible when pre-treatments are employed to mitigate fouling. A mathematical model was used to evaluate the fouling mechanism, showing that the deposition of particulate and precipitated material occurred in all tests; however, the fouling dynamic depends on the pre-treatment employed (filtration, or filtration associated with a pH adjustment). The deposit layer formed by particles is not cohesive, allowing its entrainment to the bulk flow. The precipitate fouling showed a minimal tendency to entrainment. Also, precipitate fouling served as a coupling agent among adjacent particles, increasing the fouling layer cohesion.