Polymers as Natural Composites: An Engineering Insight

2015 ◽  
pp. 161-208
Author(s):  
G Kozlov ◽  
I Dolbin ◽  
Jozef Richert ◽  
O Stoyanov ◽  
G Zaikov
Keyword(s):  
Natural Composites

Role of Ti and Y in the nucleation of the primary α-Al of Al7075–Ti–Y natural composites and influence of ultrasonic vibration

2021 ◽  
Vol 112 (8) ◽  
pp. 652-664
Author(s):  
Xiao-Hui Chen ◽  
Lei Liu ◽  
Jinbo Li ◽  
Fayun Zhang
Keyword(s):  
Reaction Kinetics ◽  
Grain Refinement ◽  
Ultrasonic Vibration ◽  
Nano Particles ◽  
Influencing Mechanism ◽  
Ultrasonic Time ◽  
Natural Composites ◽  
Corrosion Pits ◽  
Main Factor

Abstract Al7075–Ti–Y natural composites were prepared by using a combination of ultrasonic vibration and casting. The effects of titanium (Ti) and yttrium (Y) on the nucleation of primary α-Al were studied and the influencing mechanism of Y on the TiAl3 formation was analysed. Furthermore, a reaction kinetics model of TiAl3 under ultrasonic vibration was established. The results showed that the uniformly distributed TiAl3 and Al3Y nano-particles resulted in grain refinement. Y changed the morphology of TiAl3 and the appearance of corrosion pits was related to the fact that Y was dissolved within the TiAl3 structure to form Ti(Al,Y)3. The established model revealed that ultrasonic vibration significantly promoted the formation of TiAl3, and that ultrasonic time was the main factor affecting its growth.

Fabrication and Mechanical Properties of Hybrid Natural Composite

2015 ◽  
Vol 813-814 ◽  
pp. 57-61 ◽  
Author(s):  
R. Venkatakrishnan ◽  
T. Senthilvelan ◽  
T. Vijayakumar
Keyword(s):  
Natural Fibers ◽  
Cashew Nut Shell Liquid ◽  
Strong Light ◽  
Natural Resin ◽  
Cashew Nut ◽  
Banana Fibers ◽  
Natural Composite Materials ◽  
Natural Composites ◽  
Cashew Nut Shell ◽  
Natural Composite

In recent years, natural composite materials have replaced many conventional ones, such as metals and synthetic resin composites in many applications. This is due to the advantage of hybrid natural composite over the conventional materials. The natural composites are made up of both reinforcement and matrix materials which are obtained by the natural resources. Natural fibers reinforcement are strong, light weight, renewable, cheap, completely or partially recyclable, and biodegradable. In this work sisal and banana fibers have been used as the main reinforcing materials to increase the effectiveness of natural fibers. Cashew nut shell liquid (CNSL) resin is a natural resin that can be obtained from cashew nut. CNSL is essentially a mixture of phenol extracted from the shell of the cashew nut and is a good natural alternative to chemically derived phenol.

Mechanical Properties of Jute/PLA Injection Molded Products-All Natural Composites

2011 ◽  
Author(s):  
Masuo Murakami ◽  
Yuqiu Yang ◽  
Hiroyuki Hamada
Keyword(s):  
Mechanical Properties ◽  
Injection Molding ◽  
Density Measurement ◽  
The Other ◽  
Jute Fiber ◽  
Poly Lactic Acid ◽  
Thermoplastic Polymer ◽  
Environmental Friendly ◽  
Molding Condition ◽  
Natural Composites

Natural composites have been important materials system due to preservation of earth environments. Natural fibers such as jute, hemp, bagasse and so on are very good candidate of natural composites as reinforcements. On the other hand regarding matrix parts thermosetting polymer and thermoplastic polymer deriver form petrochemical products are not environmental friendly material, even if thermoplastic polymer can be recycled. In order to create fully environmental friendly material (FEFM) biodegradable polymer which can be deriver from natural resources is needed. Therefore poly(lactic acid) (PLA) polymer is very good material for the FEFM. However, PLA is very brittle polymer, so that polymer chemists have been made the efforts to make tough PLA. In this paper Jute/PLA composites was fabricated by injection moldings and mechanical properties were measured. It is believable that industries will have much attention to FEFM, so that injection molding was adopted to fabricate the composites. Long fiber pellet pultrusion technique was adopted to prepare jute fiber-PLA pellet (Jute/PLA). Because it is a new method which is able to fabricate composite pellets with relative long length fibers for injection molding process, where, jute yarns were continuously pulled and coated with PLA resin. Here two kinds of PLA materials were used including the one with mold releasing agent and the other is without it. After pass through a heated die whereby PLA resin impregnates into the jute yarns and sufficient cooling, the impregnated jute yarns were cut into pellets. Then Jute/PLA pellets were fed into injection machine to make dumbbell shape specimens. In current study, the effects of temperature of heat die i.e. impregnation temperature and the kind of PLA were focused to get optimum molding condition. The volume fractions of jute fiber in pellet were measured by several measuring method including image analyzing, density measurement and dissolution methods. And the mechanical property were investigated by tensile and Izod testing. It is found that 250 degree is much suitable for Jute/PLA long fiber pultrusion process. Additionally the jute fibers seem much effective to increase the tensile modulus and the Izod strength. That is to say, the addition of Jute fiber in PLA, the brittle property can be improved.

scholarly journals Critical Review of the Parameters Affecting the Effectiveness of Moisture Absorption Treatments Used for Natural Composites

2019 ◽  
Vol 3 (1) ◽  
pp. 27 ◽  
Author(s):  
Ahmad Al-Maharma ◽  
Naser Al-Huniti
Keyword(s):  
Moisture Absorption ◽  
Natural Fiber ◽  
Natural Fibers ◽  
Complete Discussion ◽  
Natural Composites ◽  
Review Study ◽  
Fiber Matrix ◽  
Physical Treatments ◽  
The Cost ◽  
High Degree

Natural composites can be fabricated through reinforcing either synthetic or bio-based polymers with hydrophilic natural fibers. Ultimate moisture absorption resistance at the fiber–matrix interface can be achieved when hydrophilic natural fibers are used to reinforce biopolymers due to the high degree of compatibility between them. However, the cost of biopolymers is several times higher than that of their synthetic counterparts, which hinders their dissemination in various industries. In order to produce economically feasible natural composites, synthetic resins are frequently reinforced with hydrophilic fibers, which increases the incompatibility issues such as the creation of voids and delamination at fiber–matrix interfaces. Therefore, applying chemical and/or physical treatments to eliminate the aforementioned drawbacks is of primary importance. However, it is demonstrated through this review study that these treatments do not guarantee a sufficient improvement of the moisture absorption properties of natural composites, and the moisture treatments should be applied under the consideration of the following parameters: (i) type of hosting matrix; (ii) type of natural fiber; (iii) loading of natural fiber; (iv) the hybridization of natural fibers with mineral/synthetic counterparts; (v) implantation of nanofillers. Complete discussion about each of these parameters is developed through this study.

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