CM: Chlorinated polyethylene rubber

General Properties

Short Name:

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Chlorinated polyethylene rubber

Chlorinated polyethylene, abbreviated CM or CPE, is formed by the direct reaction of polyethylene with chlorine. The properties of the resulting rubber are dependent on the chlorine content and distribution. The typical chlorine content is between approx. 25% and 48%. Added stabilizers prevent elimination of the chlorine from the polymer.

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	-25 to -5°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	-
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	-
Decomposition reactionA decomposition reaction is a thermally induced reaction of a chemical compound forming solid and/or gaseous products. Decomposition Temperature	320 to 340 / 465 to 480°C
Young's Modulus	2 to 15 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	175 to 200 *10^-6/K
Specific Heat Capacity	-
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	0.11 to 0.13 W/(m*K)
DensityThe mass density is defined as the ratio between mass and volume. Density	1.08 to 1.27 g/cm³
Morphology	Amorphous rubber
General properties	Good ozone and UV light resistance
Processing	Cross linking by means of peroxides with activators, radiation or by means of thiazoles
Applications	Cable sheathings. Technical rubber products. Hoses for engines. Impact modifier for PVC

NETZSCH Measurement

Instrument	DSC 204 `F1` `Phoenix^®`
Sample Mass	14.21 mg
IsothermalTests at controlled and constant temperature are called isothermal.Isothermal Phase	5 min
Heating/Colling Rates	10 K/min
Crucible	Al, pierced lid
Atmosphere	N₂ (40 ml/min)

Evaluation

As an entirely amorphous polymer, CM shows a 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 step at -11°C (midpoint, both heatings). 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 temperature determines the minimal application temperature* for rubber materials. Below 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, the polymer loses elasticity and gets hard and brittle. The step height (Δc_p) is evaluated as 0.49 J/(g.K) in both heatings.

* DIN 3761-15 - Rotary shaft lip type seals for automobils; test; determination of cold resistant of elastomers; differential-thermoanalysis (withdrawn)