Viscoelastic and dry-sliding wear properties of basalt fiber-reinforced composites based on a surface-modified graphene oxide/epoxy matrix

The current study focuses on the development of silanized graphene oxide reinforced basalt fiber/epoxy composites for enhanced tribological and viscoelastic properties. The modified-graphene oxide nanoplatelets were characterized using energy-dispersive X-ray spectroscopy, and Raman analyses. Pin-on-disk wear test and dynamic mechanical thermal analysis were conducted to determine the tribological and viscoelastic properties of the fabricated specimens with different silanized-graphene oxide loadings in the matrix (0–0.5 wt.% at a step of 0.1). The multiscale specimens were fabricated using the hand lay-up technique. The best silanized-graphene oxide loading for effectively enhancing the tribological properties was found to be 0.4 wt.%, whose wear rate and friction coefficient were 62% and 44%, respectively lower than those of the neat basalt/epoxy composite. The examination of the worn surfaces showed the enhanced basalt fiber/epoxy bonding in graphene oxide-reinforced specimen. From the results of dynamic mechanical thermal analysis, the specimen filled with 0.4 wt.% silanized-graphene oxide demonstrated the highest increase of 130% and 13.6℃ in the storage modulus and glass transition temperature as compared to the neat composite. This study indicated that the addition of silanized-graphene oxide considerably enhanced the tribological and viscoelastic properties of the fibrous composites.

Poly(Vinyl Alcohol) Fiber Reinforced High Density Poly(Ethylene) Composites: Dynamic Mechanical Thermal Analysis

In the present work, high density polyethylene (HDPE)/poly (vinyl alcohol) (PVA) fiber composites with four different PVA fiber loadings (i.e. 0, 5, 10, 20 wt%) have been prepared via melt compounding method using a twin-screw extruder. The composites were characterized for their morphology by using a scanning electron microscopy (SEM). Whereas, the dynamic mechanical thermal analysis (DMTA) was carried out by using an oscillatory rheometer. The DMTA test was carried out under torsion mode using temperature sweep test on rectangular composites samples. The DMTA results showed that the storage modulus (G¢) of the composites were higher than that of the neat HDPE and increased with increasing PVA fiber loadings. This indicated that there was a considerable stiffness enhancement of the composites. For example, at temperature of 60°C, the increases of stiffness (i.e. storage modulus) of the composites were approximately 3, 31, and 54% for PVAC-5, 10, and 20, respectively. Whereas, at higher temperature (i.e. 120°C), the increases were about 4, 50, and 98% for PVAC-5, 10, and 20, respectively. These results indicated that even at higher temperatures, the enhancement of storage modulus of the composites was still high.