There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

Biocomposites reinforced with natural fibers: 2000–2010

https://cyberleninka.org/article/n/768408.pdf

Mechanical properties of graphene and graphene-based nanocomposites

Natural fibers are getting attention from researchers and academician to utilize in polymer composites due to their ecofriendly nature and sustainability. The aim of this review article is to provide a comprehensive review of the foremost appropriate as well as widely used natural fiber reinforced polymer composites (NFPCs) and their applications. In addition, it presents summary of various surface treatments applied to natural fibers and their effect on NFPCs properties. The properties of NFPCs vary with fiber type and fiber source as well as fiber structure. The effects of various chemical treatments on the mechanical and thermal properties of natural fibers reinforcements thermosetting and thermoplastics composites were studied. A number of drawbacks of NFPCs like higher water absorption, inferior fire resistance, and lower mechanical properties limited its applications. Impacts of chemical treatment on the water absorption, tribology, viscoelastic behavior, relaxation behavior, energy absorption flames retardancy, and biodegradability properties of NFPCs were also highlighted. The applications of NFPCs in automobile and construction industry and other applications are demonstrated. It concluded that chemical treatment of the natural fiber improved adhesion between the fiber surface and the polymer matrix which ultimately enhanced physicomechanical and thermochemical properties of the NFPCs.

/pdf/a-review-on-natural-fiber-reinforced-polymer-composite-and-24eoqfvi7o.pdf

A Review on Natural Fiber Reinforced Polymer Composite and Its Applications

CRT-400.05 Serological and Molecular Detection of Cardiotropic Viruses in Adults With Myocarditis in Egypt

Nanotubes are one of the most important classes of 1D nanomaterial which can be used as reinforcing filler for the polymers and biopolymers. Out of several organic/inorganic nanotubes, carbon nanotubes (CNTs) and halloysite nanotubes (HNTs) were most studied due to their high aspect ratio, outstanding mechanical and thermal properties. Nanotubes have potential to increase the physical properties of the biopolymer even at very low loading. The properties of nanotube-filled nanocomposite depend on various parameters like the aspect ratio, dispersion, and interaction between filler and polymer. To improve the utilization and maximum potential of these fillers, it is important to understand the mechanisms of reinforcement. It will help the future researchers to find out the limitations and issues with existent processing method of nanotube-based nanocomposite which is required for further improvement. In this regard, this chapter will help the researchers to fully understand the current progress in processing method, issues, and possible methods to prepare an ideal nanotube and biopolymer-based nanocomposites. This chapter will discuss only biopolymer-based nanocomposites filled by the two most important 1D tubular nanofillers, which are CNT and HNT. This study has been divided into three subtopics, namely (i) thermoplastic nanocomposites, (ii) thermoset nanocomposites, and (iii) natural rubber (NR) nanocomposites. It focuses on the fabrication processes, properties, and potential applications of CNT and HNT biopolymer nanocomposites.

Nanotube/Biopolymer Nanocomposites

The incorporation of fermented chitin nanowhiskers (FCHW) into poly(lactic acid) (PLA) increased the tensile modulus and strength of PLA at the expense of ductility. The brittleness of PLA can be overcome with the use of plasticizer such as polyethylene glycols (PEG). The objective of this study is to investigate the effect of FCHW on the tensile and thermal properties PLA incorporated with PEG as plasticizer (PLA/PEG). PLA/PEG and FCHW reinforced PLA/PEG nanocomposites were prepared using solution mixing technique. Thermogravimetric analysis (TGA) was used to determine the thermal properties while tensile properties were determined from the tensile test. The incorporation of PEG successfully increased the ductility and tensile strength of PLA at the expense of modulus. Based on the tensile properties, 5 phr PEG was chosen for further investigation on the effect of FCHW on PEG modified PLA. Incorporation of 1 phr FCHW PLA/PEG increased the tensile strength and Young’s modulus. However, the tensile strength decreased with further addition of FCHW. The elongation at break of PLA/PEG decreased drastically with the incorporation of 1 phr FCHW and decreased gradually with further increase of FCHW. The thermal stability from TGA of FCHW reinforced PLA/PEG nanocomposites at 5 phr FCHW content was observed to be significantly higher compared to PLA/PEG, as indicated by T20 and Tmax.

/pdf/exploring-the-effects-of-fermented-chitin-nanowhiskers-on-17eoti7v7o.pdf

Exploring the Effects of Fermented Chitin Nanowhiskers on Tensile and Thermal Properties of Poly(ethylene glycol) modified Polylactic Acid Nanocomposites

Halloysite nanotubes (HNT) has gained much attention for research due to its reinforcing effect in mechanical properties, thermal stability, and nucleating effect. In this study, poly(lactic acid)/core-shell rubber/halloysite nanotubes (PLA/CSR/HNT) nanocomposites were prepared through melt blending, followed by compression molding and cut into different test specimens according to ASTM standards. The incorporation of HNT was performed at different content (0.5, 1.0, 1.5 and 2.0 phr) to study the effect of HNT content on mechanical, physical and thermal properties of impact modified PLA (PLA/CSR). It was found that the flexural strength of impact modified PLA improved significantly by 26.3% when 1.0 phr of HNT was incorporated while the flexural modulus recorded the highest reading at 1955 MPa by the incorporation of 0.5 phr HNT. The results revealed that agglomeration caused by higher content of HNT decreased the flexural properties of PLA/CSR/HNT compared to PLA/CSR. The water absorption and biodegradability of PLA/CSR/HNT were improved, primarily due to the hydrophilic nature of HNT which promoted the interaction with water molecules. From TGA results, 2.0 phr HNT was reported to greatly improve the thermal stability of PLA/CSR/HNT by a higher shift of degradation temperature. Based on DSC thermograms, a decline in the degree of crystallinity of PLA/CSR/HNT was observed when HNT was incorporated which could be due to inhibition of crystallization by HNT in PLA/CSR/HNT nanocomposites. In conclusion, incorporation of HNT at low content into impact modified PLA showed appreciable improvement in the mechanical, physical, and thermal properties of impact modified PLA.

Azman Hassan

Papers

CRT-400.05 Serological and Molecular Detection of Cardiotropic Viruses in Adults With Myocarditis in Egypt

Nanotube/Biopolymer Nanocomposites

Exploring the Effects of Fermented Chitin Nanowhiskers on Tensile and Thermal Properties of Poly(ethylene glycol) modified Polylactic Acid Nanocomposites

Effect of halloysite nanotubes on the mechanical, physical and thermal properties of impact modified poly(lactic acid)

Pencirian dan perawatan gentian daun nenas termoplastik komposit bagi penggunaan pembinaan)