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| Peptizer 66 |
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Akrochem Peptizer 66 is an activated 2,2'-dibenzamido diphenyldisulfide (DBDD) absorbed on clay.
It can be used as a processing aid/viscosity reducer for natural and synthetic rubbers.
Peptizer 66 is an effective chemical peptizer primarily used for natural rubber.
Recommended dosage levels in natural rubber are 0.05 to 0.50 phr(as final mixing temperature increases, the lower levels should be used).
Synthetic rubbers require approximately 2.0 phr.
More specific dosage recommendations are included in this data sheet.
Benefits of using Peptizer 66 :
-lower viscosity/improved processing
-lower dump temperatures with subsequent mixing
-improved mold flow
-improved uniformity of extrusions and calendared sheets
-little effect on vulcanizate properties vs. mechanically masticated rubber
-acceptable under FDA regulation 21 CFR 177.2600
Peptizer 66 disperses readily in rubber and should be added at the beginning of the mixing cycle, using either internal mixers or open mills.
Viscosity reduction is most effective when the rubber and peptizer are premasticated before adding other ingredients.
It is possible to eliminate the premastication step in internal mixers, where temperatures exceed 212'F/100'C, by adding carbon black, zinc oxide, stearic acid, and oils after the Peptizer 66 addition.
It is important, however, that sulfur, antioxidants, retarders, and accelerators be added at the end of the mix cycle since they will interfere with peptization.
Recommended levels of addition for natural rubber are as follows:
* 0.05-0.20 phr in mixes without carbon black that dump between 266°F (130'C) and 338'F (170'C).
* 0.20-0.50 phr on rubber mills without carbon black at temperatures of 158'F (70'C) to 194'F (90'C).
* When carbon black is added during peptization, use approximately twice the level of Peptizer 66 with the processing conditions above.
Recommended level of addition in synthetic rubbers is about 2.0 phr with processing temperatures between 266'F and 302'F.
However for styrene butadiene (SBR) it is recommended not to exceed 266'F processing temperatures to prevent possible cyclization reactions.
If higher than recommended levels of Peptizer 66 are used, be sure antioxidant is present in the compound to prevent unfavorable aging of vulcanizates.
Peptizer 66 has a greenish cast and can discolor light-colored stocks (white, tans, yellows). |
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Appearance : grayish powder
Specific Gravity: 1.83
Active DBDD: 40% approx.
Ash content: 47%
Solubility: partially soluble in organic solvents, practically insoluble in water |
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