General Properties
Short Name:
Name:
CR
Chloroprene rubber
Chloroprene rubber (CR) is sometimes also called chlorobutadiene rubber since it is produced from 2-chlorine-1,3-butadiene (chloroprene). The ratio between the trans and cis position of the double bonds is approx. 9:1. Depending on the production process, different CR types are available.
Structural Formula
Properties
| Glass Transition Temperature | -45 to -30°C |
|---|---|
| Melting Temperature | 40 to 75°C |
| Melting Enthalpy | 1 to 10 J/g |
| Decomposition Temperature | 365 to 380 / 445 to 460°C |
| Young's Modulus | - |
| Coefficient of Linear Thermal Expansion | 185 to 250 *10-6/K |
| Specific Heat Capacity | - |
| Thermal Conductivity | 0.18 to 0.20 W/(m*K) |
| Density | 1.25 g/cm³ |
| Morphology | Rubber |
| General properties | Good mechanical properties and elasticity. Good ozone, weather, chemical and aging resistance. High non-inflammability |
| Processing | Thermally with diamine, with hydroxyphenyl or a mixture of zinc and magnesium oxides or by reaction with ethylenethiourea |
| Applications | Technical rubber goods (e.g., seals, profiles). Automobile industry. Electrical industry. Textile industry. Adhesives, hoses, coatings |
NETZSCH Measurement
| Instrument | DSC 204 F1 Phoenix® |
| Sample Mass | 21.18 mg |
| Isothermal Phase | 8 min |
| Heating/Colling Rates | 10 K/min |
| Crucible | Al, pierced lid |
| Atmosphere | N2 (40 ml/min) |
Evaluation
As an amorphous polymer, CR shows a glass transition at approx. -35°C (midpoint) in both heatings with a step height (Δcp) of 0.38 J/(g*K) in the 2nd heating (red). The small endothermal effect at 45°C (peak temperature) in the 1st heating (blue) is probably due to the melting of an additive, which, in the molten state, dissolves in the elastomer matrix and is therefore no longer visible in the 2nd heating (red).