PA12: Polyamide 12

General Properties

Short Name:

Name: 

PA12

Polyamide 12


Of all polyamides, polyamide 12 absorbs the least amount of water. The higher the ration of -CH2 groups to -CONH- groups, the lower the water absorption and the better the dimensional accuracy. PA12 features a lower stability and hardness than PA6 und PA6.6.

Structural Formula


Properties

Glass Transition TemperatureThe glass transition is one of the most important properties of amorphous and semi-crystalline materials, e.g., inorganic glasses, amorphous metals, polymers, pharmaceuticals and food ingredients, etc., and describes the temperature region where the mechanical properties of the materials change from hard and brittle to more soft, deformable or rubbery.Glass Transition Temperature40 to 50°C
Melting Temperatures and EnthalpiesThe enthalpy of fusion of a substance, also known as latent heat, is a measure of the energy input, typically heat, which is necessary to convert a substance from solid to liquid state. The melting point of a substance is the temperature at which it changes state from solid (crystalline) to liquid (isotropic melt).Melting Temperature170 to 180°C
Melting Temperatures and EnthalpiesThe enthalpy of fusion of a substance, also known as latent heat, is a measure of the energy input, typically heat, which is necessary to convert a substance from solid to liquid state. The melting point of a substance is the temperature at which it changes state from solid (crystalline) to liquid (isotropic melt).Melting Enthalpy95 J/g
Decomposition reactionA decomposition reaction is a thermally induced reaction of a chemical compound forming solid and/or gaseous products. Decomposition Temperature465 to 475°C
Young's Modulus1400 MPa
Coefficient of Linear Thermal Expansion (CLTE/CTE)The coefficient of linear thermal expansion (CLTE) describes the length change of a material as a function of the temperature.Coefficient of Linear Thermal Expansion120 to 140 *10-6/K
Specific Heat Capacity1.17 to 1.26 J/(g*K)
Thermal ConductivityThermal conductivity (λ with the unit W/(m•K)) describes the transport of energy – in the form of heat – through a body of mass as the result of a temperature gradient (see fig. 1). According to the second law of thermodynamics, heat always flows in the direction of the lower temperature.Thermal Conductivity0.22 to 0.24 W/(m*K)
DensityThe mass density is defined as the ratio between mass and volume. Density1.01 to 1.04 g/cm³
MorphologySemi-crystalline thermoplastic
General propertiesHigh impact strength. Good chemical resistance. Very good StressStress is defined as a level of force applied on a sample with a well-defined cross section. (Stress = force/area). Samples having a circular or rectangular cross section can be compressed or stretched. Elastic materials like rubber can be stretched up to 5 to 10 times their original length.stress cracking resistance. Good sliding-friction behavior
ProcessingExtrusion
ApplicationsMechanical and apparatus engineering (e.g., bearing and drive elements in humid environments requiring high stability). Automotive engineering. Electrical engineering. Packaging. Medical engineering

NETZSCH Measurement

InstrumentDSC 204 F1 Phoenix®
Sample Mass11.55 mg
IsothermalTests at controlled and constant temperature are called isothermal.Isothermal Phase3 min
Heating/Colling Rates10 K/min
CrucibleAl, pierced lid
AtmosphereN2 (50 ml/min)

Evaluation

In this measurement, evaporation of water occurred at 94°C (peak temperature 1st heating, blue). The shift in the position of the Glass Transition TemperatureThe glass transition is one of the most important properties of amorphous and semi-crystalline materials, e.g., inorganic glasses, amorphous metals, polymers, pharmaceuticals and food ingredients, etc., and describes the temperature region where the mechanical properties of the materials change from hard and brittle to more soft, deformable or rubbery.glass transition in the 2nd heating (red, Tg of 43°C – midpoint with a Δcp value of 0.11 J/(g·K)) after water evaporation was smaller than that on page 95. The cooling rate selected in the experiment (in this case 10 K/min) was lower than the cooling rates polymer granulates generally experience during production. Therefore, the amorphous content of the sample was lower in the 2nd heating. This thesis is confirmed by the relatively high step height (Δcp) of the Glass Transition TemperatureThe glass transition is one of the most important properties of amorphous and semi-crystalline materials, e.g., inorganic glasses, amorphous metals, polymers, pharmaceuticals and food ingredients, etc., and describes the temperature region where the mechanical properties of the materials change from hard and brittle to more soft, deformable or rubbery.glass transition in the 1st heating (blue) as well as the ExothermicA sample transition or a reaction is exothermic if heat is generated.exothermal post-CrystallizationCrystallization is the physical process of hardening during the formation and growth of crystals. During this process, heat of crystallization is released.crystallization (peak temperature: 159°C, CrystallizationCrystallization is the physical process of hardening during the formation and growth of crystals. During this process, heat of crystallization is released.crystallization enthalpy: 2.2 J/g) that occurred immediately prior to melting. 

The endothermal melting effect at 178°C (peak temperature, 2nd heating) exhibited a melting enthalpy of approx. 34 J/g.