Chloroprene (CR) from DuPont Performance Elastomers

Technical Data:
  Chemical Resistance Guide
  Neoprene polychloroprene
  Neoprene Applications

Oil resistant rubbers. G Types have best tear strength and flex crack resistance. T Types contain gel for best processing. RT Types are resistant to crystallization at low temperature. Neoprene W is a general purpose polymer. Different viscosity versions are shown below the main types. Other grades are available for more specialized applications, including latex and adhesive polymers.

Adhesive Grades

          Neoprene AD-20
Chloroprene polymer designed for use in high strength solution adhesives requiring rapid rates of strength development. More color-stable than Neoprene AC during storage. Primary use is in contact adhesives that require high initial and ultimate bond strength and ability to form bonds with minimum pressure after long open assembly periods. Neoprene AD can be dissolved without milling, or can be milled before solution (for rheology control), to cover a broad range of solution viscosity. It is soluble in solvents with various evaporation rates. Compounded adhesives can be stored in iron containers without the discoloration experienced with compounds based on Neoprene AC.

          Neoprene NPR 2008
A high viscosity Neoprene polymer designed specifically to provide improved solution characteristics when compared to Neoprene WHV, and is primary used in combination with fast-crystallizing Neoprene grades to impart high solution viscosity. Solutions of Neoprene NPR 2008 have higher viscosities than solutions of Neoprene AD 20. Compounded solution adhesives based on Neoprene NPR 2008 provide more tack and a slower rate of bond strength development that adhesives based on Neoprene AD 20.

Neoprene NPR 2008 can be dissolved without milling or can be milled before dissolution (for rheology control). Breakdown of Neoprene NPR 2008 by milling is more difficult than breakdown of Neoprene AD 20 under similar milling conditions.

General Purpose Grades

          Neoprene GNA-M1
          Neoprene GNA-M2
Neoprene GNA is a sulfur-modified polychloroprene stabilized with a thiuram disulfide and a staining antioxidant. It should not be used in applications where resistance to staining or discoloration of finishes is necessary. Neoprene GNA breaks down, or softens, under the mechanical shear imposed during mixing to produce smooth-processing compounds. It does not break down quite as rapidly as Neoprene GRT, so its compounds are less tacky and have somewhat less building tack than compounds of other G types.

          Neoprene GW-M2
Neoprene GW is a sulfur-modified polychloroprene stabilized with a thiuram disulfide. The crystallization rate of Neoprene GW is slightly faster than that of Neoprene GRT. Compounds of Neoprene GW cured with metal oxides alone have excellent processing safety, yet cure rapidly. Although not required, cure accelerators can be used and are advantageous for some applications.

          Neoprene TW
          Neoprene TW-100
Neoprene TW and TW-100 are non-staining, general purpose polychloroprenes that contain gel for good processability. Neoprene TW and TW-100 do not decrease in molecular weight during mixing and processing and cannot be chemically peptized. However, some reduction in viscosity may occur under high shear conditions. The degree of softening is greater for a higher molecular weight polymer such as Neoprene TW-100. Compounds of Neoprene TW and TW-100 mix faster and cooler and have better mill release than compounds of Neoprene GNA or GRT. Neoprene TW is an excellent polymer base for extruded products, providing high extrusion speed, low die swell, excellent definition, and very good collapse resistance. In calendered goods, it produces smooth sheeting with low nerve and shrinkage. Neoprene TW-100 offers these same benefits in a higher viscosity range suitable for more heavily loaded compounds.

          Neoprene W
          Neoprene WHV
          Neoprene WHV-100
          Neoprene WM-1
Non-staining, general-purpose polychloroprenes. The four grades differ only in Mooney viscosity. Neoprene W synthetic rubber and its viscosity grades do not decrease in molecular weight, either under mechanical shear or with chemical peptization. However, some reduction in viscosity may occur under high shear condition. The degree of softening is greater for the higher molecular weight polymers, Neoprene WHV and WHV-100. Compounds of Neoprene W and its viscosity grades mix faster, develop less heat during mixing, have better mill release, and yield extrudates that are more resistant to distortion than do compounds of Neoprene GNA or GRT.