Finite and Renewable Resources

polymer resin

The ________ which binds the fibres together is not strong but it is stiff.

Chipboard

________ contains randomly arranged wood chips bonded together by a glue, so it is strong in all directions.

covalent bonds

Thermosoftening plastics do not have ________ between neighbouring polymer molecules, so the molecules can move over each other when heated and the plastic melts.

Plastics

________ can be put into one of two categories, depending on how they respond when heated.

Wood itself

________ is a natural composite material.

High density poly

________ (ethene) has less branching of the polymer chains, so the molecules line up much more closely.

pure metals

________dont always have the properties needed

one material embedded

composites are made of_____in another

Fibres or fragments

______of a material are surrounded by a matrix acting as a binder

Carbon fibre composites also

_____have a polymer like matrix

wood

natural composite of cellulose fibres

Composites are generally

_made of two different materials

clay

is a soft material when its dug up so can be moulded

Polymers properties

insulators of heat and electricity, flexible and easily moulded

Metals properties

malleable, good conductors of heat and electricity, ductile, shiny and stiff