Properties

From Green Plastics

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The properties of a material are characteristics or behaviors that it exhibits in response to the environment. There are several classes of material properties that scientists use to describe and compare different types of materials. Each of these classes (outlined below) has very specific scientific tests and units of measurement, to allow rigorous and concrete comparisons and evaluations of materials.

Physical properties

Physical properties are properties that have to do with the physical make-up of a material or the way it responds to forces or elements in the environment that do not change its chemical composition. (When the property involves a change in the actual chemical make-up of the material, it is considered a chemical property.)

Examples include:

• color
• odor
• density
• melting point
• freezing point
• boiling point
• glass transition temperature
• water absorption
• crystalline structure

Thermal properties

Thermal properties are properties that specifically have to do with the way a material responds to heat. Sometimes thermal properties are considered to be a subset of physical properties.

Examples include:

• thermal conductivity
• specific heat
• thermal shock resistance
• dilation coefficient

Electrical properties

Electrical properties are properties that specifically have to do with the way a material responds to electricity. Sometimes electrical properties are considered to be a subset of physical properties.

Examples include:

• electrical resistance
• dielectric constant

Mechanical properties

Mechanical properties are properties that specifically have to do with the way a material responds when mechanical forces are applied to it. Mechanical properties are sometimes mistakenly considered a subset of physical properties, although in most scientific language these are regarded as distinct and separate categories.

Examples include:

• tensile strength
• bending strength
• hardness
• compressive strength
• fracture toughness.

Chemical properties

Chemical properties are properties that describe the way a material reacts with its environment. Chemical properties are specifically those that involve a change in the chemical structure of the material.

Examples include:

• flamability
• biodegradability