Fracture toughening behavior of elastomer modified polyphenylene ether/polyamide blends

Processing and Characterization of Polyphenylene Ether/Polystyrene/Nylon-6 Ternary Blends

Polyphenylene ether (PPE) is a polymer with very high glass transition temperature, superior thermal stability but poor melt processability. Mainly to improve its processability and chemical resistance, it is blended with Polystyrene (PS) and Nylon-6, respectively. In this research, ternary blends of PPE/PS/Nylon-6 were prepared using co-rotating twin screw extrusion and test specimens were injection molded. The influence of Maleic anhydride and screw speed on the mechanical and thermal properties of the ternary blends was investigated. The 40/40/20 blends, without Maleic anhydride, processed at screw speed of 600 min–1 showed highest tensile, flexural and impact strengths of 65.74 MPa, 82.22 MPa and 8.88 kJ/m2, respectively. Complete miscibility of the three polymers in the ternary blend was evidenced by scanning electron micrographs. Glass transition temperature of the ternary blend was 127 °C. High thermal and dimensional stability of the blend was evidenced by lowest volatile mass and highest residual mass at 800 °C along with decomposition temperature of 458.6 °C. Maleic anhydride was not effective as compatibilizer in improving the mechanical properties of the ternary blend.

Optimization of Accelerator Mixing Ratio for EPDM Rubber Grommet to Improve Mountability Using Mixture Design

A grommet, made of ethylene propylene diene methylene (EPDM) rubber, is an integral part used for fixing and protecting the wire inserted from the outside to the inside of vehicles. Rubber compounds exhibit various mechanical properties and vulcanization characteristics depending on the accelerator mixing ratio. These mechanical properties affect the insertion and detachment forces when the grommet is manufactured and fixed to the vehicle body. In this study, we experimentally analyzed the changes in the properties of EPDM rubber depending on the vulcanization accelerator to improve the mounting performance of the grommet, and subsequently derived the optimum accelerator mixing ratio. We implemented a mixture design strategy to derive the optimum mixing ratio for obtaining the desired mechanical properties and vulcanization characteristics. The insertion and separation forces of the existing grommet were compared with those of the grommet fabricated using the derived mixing ratio and we found that the mounting performance was improved compared to the existing grommet.

Largely enhanced fracture toughness of an immiscible polyamide 6/acrylonitrile–butadiene–styrene blend achieved by adding chemically modified graphene oxide

Schematic showing of dual effect of PS–GO with PA6 and ABS components.

Compatibilization of immiscible polymer blends using graphene oxide sheets

By taking the advantage of the unique amphiphilic structure of graphene oxide sheets (GOSs), we develop here a new and effective strategy for compatibilizing immiscible polymer blends. With the incorporation of only 0.5 wt % GOSs into immiscible polyamide/polyphenylene oxide (PA/PPO, 90/10) blends, the droplet diameter of the dispersed minor phase (PPO) is dramatically reduced by more than 1 order of magnitude, indicating a largely improved compatibility in the GOS-filled polymer blends. As a result, the ductility of GOS-compatibilized polymer blends is notably elevated. The compatibilizing effect of GOSs should be due to the fact that GOSs can exhibit strong interactions with both PA and PPO phases, thus minimizing their interfacial tension. Moreover, unlike traditional copolymer compatibilizers, GOSs can also act as reinforcing fillers in polymer blends, thus remarkably enhancing their mechanical strength and thermal stability. Considering the inexpensive sources (graphite powders) and extraordinary properties of GOSs, this work may open up opportunities to produce new compatibilizers that are of great interest in the industrial field.