Mr Harding Flashcards
what is toughness
ability to absorb energy
what is flexibility
ability to bend without deformation
what is elasticity
a materials resistance to distorted without plastic deformation
what is mouldability
the ability of a material to be shaped
what is a thermoplastic
a plastic that can be melted at a consistent melting point and reformed multiple times
what is a thermosetting plastic
a plastic that after setting cannot be re-melted and reformed
what are physical properties of polymers
-insulation
-self finishing
-uv resistance
-melting points
-transparency/translucency
-resistance to chemicals
-ability to be combined with additives
what is thermally insulating polymers
low heat transfer plastics, used in kitchen products, low cost
what are electrically insulating polymers
all plastics are non-conductive (no free electrons) and are used to insulate plug switches and such
typical melting conditions of thermoplastics
go soft and pliable under relatively low temperatures and pressures due to weak bonds, release noxious gasses
typical melting conditions of thermosetting plastics
char and burn, remain rigid, get more brittle, very high melting points and pressures
what is UV resistance
the ability to resist bleaching and brittleness under UV light
what is chemical resistance
ability to remain unaffected when exposed to different chemicals (defined by the inertness of the oils used) e.g bleach bottles
what is transparency
how permeable to light radiation it is, often comes as a film or sheet, used in windscreens
what is translucency
when the amount of light going through an object is limited making it harder for light to permeate through it
what is self finishing
when no additional surface finishing is required such as polishing or adding high gloss chemicals
what are plasticizers
an additive used to loosen the chemical bonds for easy mouldability (flow into moulds better)
what are thermoxidisers
an additive used to remove oxygen and prevent discolouration during moulding
what are stabilizers
an additive for the prevention of UV deterioration or temp increase
what are antistatic agents
additives to prevent a static charge building up on a plastics surface
what are colourants
an additive to make a plastic more aesthetically pleasing
what are fire retardants
additives to increase melting points and reduce flammability
what are bio batch materials
additives to make thermoplastics degrade into microplastics more quickly
what are the additives for performance
thermoxidants (anti-oxidants) , stabilizers