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 Temperature	40 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 Temperature	170 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 Enthalpy	95 J/g
Decomposition reactionA decomposition reaction is a thermally induced reaction of a chemical compound forming solid and/or gaseous products. Decomposition Temperature	465 to 475°C
Young's Modulus	1400 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 Expansion	120 to 140 *10^-6/K
Specific Heat Capacity	1.17 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 Conductivity	0.22 to 0.24 W/(m*K)
DensityThe mass density is defined as the ratio between mass and volume. Density	1.01 to 1.04 g/cm³
Morphology	Semi-crystalline thermoplastic
General properties	High 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
Processing	Extrusion
Applications	Mechanical and apparatus engineering (e.g., bearing and drive elements in humid environments requiring high stability). Automotive engineering. Electrical engineering. Packaging. Medical engineering

NETZSCH Measurement

Instrument	DSC 204 `F1` `Phoenix^®`
Sample Mass	11.55 mg
IsothermalTests at controlled and constant temperature are called isothermal.Isothermal Phase	3 min
Heating/Colling Rates	10 K/min
Crucible	Al, pierced lid
Atmosphere	N₂ (50 ml/min)

Evaluation

In this measurement, evaporation of water occurred at 94°C (peak temperature 1^st 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 2^nd heating (red, T_g of 43°C – midpoint with a Δc_p 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 2^nd heating. This thesis is confirmed by the relatively high step height (Δc_p) 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 1^st heating (blue) as well as the ExothermicA sample transition or a reaction is exothermic if heat is generated.exothermal Post Crystallization (Cold Crystallization)The post crystallization of semi-crystalline plastics occurs primarily at elevated temperatures and increased molecular mobility above the glass transition.post-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, 2^nd heating) exhibited a melting enthalpy of approx. 34 J/g.