Distearyl thiodipropionate; Antioxidant DSTDP, ADCHEM DSTDP
DSTDP Powder
DSTDP Pastille
Chemical name: Distearyl thiodipropionate
Chemical formula: S(CH2CH2COOC18H37)2
Molecular weight: 683.18
CAS No.: 693-36-7
Description of properties: This product is white crystalline powder or granules. Insoluble in water, soluble in benzene and toluene.
Synonym
Antioxidant DSTDP,
Irganox PS 802, Cyanox Stdp
3,3-Thiodipropionic acid di-n-octadecyl ester
Distearyl 3,3-thiodipropionate
Antioxidant DSTDP
Distearyl thiodipropionate
Antioxidant-STDP
3,3′-Thiodipropionic acid dioctadecyl ester
Specification
Appearance：White crystalline powder/ Pastilles
Ash：Max.0.10%
Melting point：63.5-68.5℃
Application
Antioxidant DSTDP is a good auxiliary antioxidant and is widely used in polypropylene, polyethylene, polyvinyl chloride, ABS and lubricating oil. It has high-melting and low- volatility.
DSTDP can also be used in combination with phenolic antioxidants and ultraviolet absorbers to produce synergistic effect.
From the perspective of industrial use, you can basically refer to the following five principles to choose:
1. Stability
During the production process, the antioxidant should remain stable, not easily volatilized, not discolored (or not colored), not decomposed, not reacted with other chemical additives, and not reacted with other chemical additives during the use environment and high-temperature processing. Other substances on the surface are exchanged and will not corrode production equipment, etc.
2. Compatibility
The macromolecules of plastic polymers are generally non-polar, while the molecules of antioxidants have different degrees of polarity, and the two have poor compatibility. Antioxidant molecules are accommodated between polymer molecules during curing.
3. Migration
The oxidation reaction of most products mainly occurs in the shallow layer, which requires the continuous transfer of antioxidants from the interior of the product to the surface to work. However, if the transfer rate is too fast, it is easy to volatilize into the environment and be lost. This loss is unavoidable, but we can start with formula design to minimize the loss.
4. Processability
If the difference between the melting point of the antioxidant and the melting range of the processing material is too large, the phenomenon of the anti-oxidant drift or the anti-oxidant screw will occur, resulting in uneven distribution of the antioxidant in the product. Therefore, when the melting point of the antioxidant is lower than the material processing temperature by more than 100 °C, the antioxidant should be made into a masterbatch of a certain concentration, and then mixed with the resin before use.
5. Security
There must be artificial labor in the production process, so the antioxidant should be non-toxic or low-toxic, dust-free or low-dust, and will not have any harmful effects on the human body during processing or use, and no pollution to the surrounding environment. No harm to animals and plants.
Antioxidants are an important branch of polymer stabilizers. In the process of material processing, more attention must be paid to the timing, type and amount of antioxidants added to avoid failure due to environmental factors.