The effect of adding natural materials waste on the mechanical properties and water absorption of epoxy composite using grey relations analysis

Recently, there has been a tendency for scientific studies to deal with natural materials as fillers and reinforcement for polymer composites, which are used in many different applications due to their environmentally friendly properties when compared to synthetic materials. The current study aims to preserve the environment by dealing with natural materials and their influence on the mechanical properties and water absorption property of the polymer composites. In this study, epoxy composites were produced from local natural sourced non-hazardous raw natural materials using grey relational analysis (GRG). The materials used for fabrication include micro-filler of pollen palm 50 μm, seashell 75 μm and epoxy resin. Nine different composites were prepared using pollen palm and seashell as reinforcement material by varying the wt % of the micro-filler. Rule of the mixture was used for formulation and wt % of (0.5, 1 and 1.5) % reinforcement and 99.5, 99 and 98.5 % epoxy (binder) were used for composites. Grey relational analysis was conducted in order to scale the multi-response performance to a single response. The results indicate that optimum performance can be achieved with the addition of 1.5 wt % micro-filler of seashell, which achieved the first rank, while the second rank achieved by 0.5 wt % micro-filler of palm pollen and seashell when compared to other composites. The addition of micro-fillers has improved greatly the mechanical properties of epoxy composites. The loading of micro-fillers has influenced the water absorption property of composites based epoxy in ascending order

Injectable Soft Tissue Nano/Micro Fillers for Facial Reconstruction

Soft Tissue augmentation is a way to restore lost tissue and also a way to reshape confidence for patients who suffer from soft tissue loss. Materials that can realize such a function are called soft tissue fillers. Among the large number of fillers, injectable fillers have attracted widespread attention in facial cosmetic fields due to their convenience and competitive performance. Meanwhile, there is a huge demand for better injectable soft tissue fillers in medical cosmetology market. This review introduces several fillers which were once used in clinical or are now still in use. Furthermore, we update recent improvements and progress on injectable filling materials hoping to contribute to its further developments.

Combined effects of interface modification and micro-filler reinforcements on the thermal and tribological performances of fabric composites

The high specific-strength of glass fibers and exceptional self-lubrication of polytetrafluoroethylene (PTFE) fibers promote the potential application of hybrid PTFE/glass fabric composites in the tribological field, but their weak interfacial adhesion and inferior thermal properties significantly inhibit their tribological performance and reliability. Herein, a hybrid of polydopamine/silicon carbide/polyethyleneimine (PDA/SiC/PEI) functional coating was co-deposited onto the hybrid PTFE/glass fabric surface through a one-step impregnation method, leading to increased surface roughness and abundant amine groups. Tensile and peeling tests showed that this functional coating offered 47.8% enhancement in the fabric/matrix interfacial adhesion without compromising the strength of the pristine fabric. Moreover, the additional incorporation of WS2, and aluminum nitride (AlN) micro-fillers contributed to the development of a high-quality tribofilm and improved the thermal properties of fabric composites. The results of wear tests proved that the hybrid-fabric composites, after the introduction of functional coating and micro-fillers, exhibited outstanding tribological performance, which was attributed to the superior interfacial adhesion as well as the synergistic enhancement effects between WS2 and AlN micro-fillers.

Characteristics of Gel Time and Dielectric Strength of Epoxy Composite According to the Mixing Ratio of Micro-Fillers

The dielectric strength and gel time of epoxy composites vary with the mixing ratio of epoxy resin, hardener, additives, filler, etc., and especially the gel time affects the productivity and economics of ultra-high-voltage (UHV) equipment. However, previous studies focused only on the dielectric strength of epoxy composites for the reliability of UHV equipment. Therefore, a study considering both the dielectric strength and gel time of the epoxy composite is required. In this paper, the characteristics of the gel time and dielectric strength of the epoxy micro-composites according to the mixing ratio of silica (SiO2) and alumina (Al2O3) micro-fillers without changing the mixing ratio of epoxy resin and hardener are analyzed. Experimental results show that the gel time decreased and the dielectric strength increased as the mixing ratio of the SiO2 micro-filler increased. Therefore, it is concluded that the gel time can be controlled by changing the mixing ratio of micro-fillers without changing the mixing ratio of the epoxy resin and hardener. In addition, experimental data can be used as basic data for economical production considering both the reliability and productivity of UHV power equipment.