Ceramics
All of us have dropped drinking glasses and mugs before and seen them break into many pieces on the floor. This begs the question: how can such brittle materials be…
Compression Blow Moulding
Compression Moulding Compression moulding is principally used for thermosetting plastics. Preheated resin is placed into a hot mould cavity. The upper section of the mould is subsequently forced down onto…
Injection Extrusion
There are a number of different methods that are commonly used for forming of polymers. These methods rely to a large extent on whether the polymer is a thermoplastic or…
VulcanisationReinforcement
Vulcanisation Vulcanisation is the process by which a chemical is added to induce the formation of cross-links between molecular chains. The process provides a stronger and more durable rubber that…
Blending Stabilisation
Blending and Alloying In blending, two immiscible (mutually insoluble) polymers are blended together to create a two-phase polymer. Generally, this will involve mixing an elastomer with a thermoplastic to create…
Molecular Mass Plasticisers
Average Molecular Mass Increasing the average molecular mass of a polymer simply means increasing the average length of the molecular chains that make up its structure. The strength of the…
Polymer Property Design
There are a number of methods commonly employed in industry to alter the key properties of polymers. These include copolymerisation, varying the degree of crystallinity, varying the average molecular mass,…
Crazing Shear Banding
Crazing Often, when an amorphous brittle polymer is loaded in tension, a phenomenon known as crazing can occur. Crazing involves the formation of small crack-shaped regions that are drawn down…
Mechanical Behaviour
Three typically different stress-strain behaviours can be observed in polymeric materials. A brittle polymer deforms elastically before fracture, a plastic polymer deforms elastically at first and then yields into a…
Properties
Viscoelasticity Viscoelasticity of a thermoplastic refers to the time-dependent nature of deformation under an applied stress. The stress required to deform the polymer is related to both the level of…
