Advantages And Disadvantages Of Thermoplastics

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2.2 MATRIX
Although the strength of composites depends primarily on the nature and type of reinforcement used. However a minor portion of the properties of composites depends on the matrix used. Naturally, reinforcements (fibres, whiskers, particulate, etc.) have limited properties and usage unless they are bonded together by matrix to form a bulk structure. This fabricated structure can then be used for several applications [R Jones, 1999].
Generally a matrix material is a component or constituent of a composite that forms the continuous phase of a composite. Primarily, the matrix portion of a composite plays the role of holding the reinforcements in position and also deform and distribute stress to the reinforcement depending on the mode …show more content…

The attractive mechanical properties of thermoplastics makes it suitable to be used in various disciplines (marine, aircraft, etc.). Thermoplastics are not cross-linked in their molecular structure hence contributing to high strength [Adjaottor, 2015]. Thermoplastics can be repeatedly softened and remoulded into other forms by heating. The high rate of recycling thermoplastics makes it convenient to be used in composite materials. Thermoplastics have a lot of advantages for engineering design applications. These advantages are high ductility, toughness, etc. Typical examples of thermosets include polyethylene (high or low density), polypropylene, nylon and acrylics. [Adjaottor, …show more content…

melting temperature (oC) 125 110
.
2.2.2.2 Thermoset matrix
Thermosets are classes of polymers that are produced from a network molecular structure of primary covalent bonds. The structure of thermosets are crosslinked by application of heat and pressure and chemical reactions occurring at high temperature. Thermosets therefore cannot be reheated and reshaped into other forms as thermoplastics do. This limitation of thermoset makes them decline in usage due to the difficulty in recycling. The advantages of thermosets for engineering design are high thermal stability, high rigidity, resistance to creep and deformation load etc. [Alfred, 1999].
Table 2.2: Properties of some common thermoset matrix
Property polyester vinyl ester Epoxy
Density (g/cm3) 1.13 1.12 1.28
Tensile strength (MPa) 77 81 76
Flexural strength (MPa) 123 138 115
Flexural modulus (MPa) 2.96 3.72 3.24
Elongation at break (%) 4.5 5.0 6.3
Heat distortion temperature (oC) 71 104

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