DISTEARYL THIODIPROPIONATE

PRODUCT IDENTIFICATION
CAS NO. 693-36-7; 1323-85-9; 115863-90-6; 60649-48-1;

DISTEARYL THIODIPROPIONATE 

EINECS NO. 211-750-5
FORMULA S[CH2CH2CO2(CH2)17CH3]2
MOL WT. 683.18
H.S. CODE 2930.90.9999
TOXICITY Oral rat LD50:>2500 mg/kg
SYNONYMS Antioxidant STDP; Distearyl thiodipropionate;
Dioctadecyl 3,3'-thiodipropionate; Dioctadecyl thiodipropionate; Distearyl 3,3'-thiodipropionate; Distearyl beta,beta'-thiodipropionate; Distearyl beta-thiodipropionate; Propionic acid 3,3'-thiodi, dioctadecyl ester; Diodipropionic acid distearyl ester;

SMILES

 C(SCCC(OCCCCCCCCCCCCCCCCCC)=O)CC (OCCCCCCCCCC CCCCCCCC)=O

CLASSIFICATION

Thiodipropionate, Antioxidant, Stabilizer

PHYSICAL AND CHEMICAL PROPERTIES
PHYSICAL STATE White crystalline powder
MELTING POINT 63 - 68 C
BOILING POINT  
SPECIFIC GRAVITY 1.027
SOLUBILITY IN WATER Insoluble

SOLVENT SOLUBILITY

 Soluble in almost organic solvents but insoluble in alcohol
AUTOIGNITION  
pH  
VAPOR DENSITY  
NFPA RATINGS

 

REFRACTIVE INDEX

  
FLASH POINT  
STABILITY Stable under ordinary conditions

GENERAL DESCRIPTION & EXTERNAL LINKS
Antioxidant is a substance added in small quantities to hydrocarbons which are susceptible to oxidation, such as rubbers, plastics, foods, and oils to inhibit or slow oxidative processes, while being itself oxidized.  Antioxidants work in two different ways. In primary antioxidants (also called free-radical scavengers), antioxidative activity is implemented by the donation of an electron or hydrogen atom to a radical derivative. These antioxidants are usually hindered amines (p-Phenylene diamine, trimethyl dihydroquinolines, alkylated diphenyl amines) or substituted phenolic compounds with one or more bulky functional groups such as a tertiary butyl at 2,6 position commonly. Butylated hydroxytoluene (BHT) is a common example of hindered phenolic antioxidant. The reaction rate, or carbocation stability, in SN1 mechanism is 3° > 2° > 1° > CH3 (no SN1) so, tertiary alkyl moiety exists in lots of phenolic antioxidant compounds. Primary antioxidants are free radical scavengers which combine with peroxy radicals and break autocatalytic cycle. In secondary antioxidants ( also called peroxide decomposers), activity is implemented by the removal of an oxidative catalyst and the consequent prevention of the initiation of oxidation. Examples of peroxide decomposer type of antioxidant are trivalent phosphorous and divalent sulfurcontaining compound such as sulfides, thiodipropionates and organophosphites. Synergistic effect is expected when primary antioxidants are used together with secondary antioxidants as primary antioxidants are not very effective against the degradation by UV oxidation. Sometimes, chelating agents are added to scavenge metal impurities which can initiate decomposition.

Distearyl thiodipropionate is used as a secondary stabilizer and antioxidant in combination with phenolic antioxidant for polymers (ABS, polypropylene, polyethylene and polyesters). It is approved to use in food packaging. It is also used stabilizer in oils, lubricants, sealants, and adhesives.

http://www.sciencedirect.com/
Mechanisms of antioxidant action: the nature of the redox behaviour of thiodipropionate esters in polypropylene

http://www.epa.gov/
....DLTDP, DTTDP and DSTDP are all produced by reacting the same intermediate, thiodipropionitrile (TDPN), with different fatty alcohols. DLTDP uses lauryl alcohol, DTTDP uses iso-tridecyl alcohol and DSTDP uses stearyl alcohol. The reaction of TDPN with the alcohols is an esterification using acid catalysts (hydrochloric acid and sulfuric acid). Water is removed under vacuum to drive the esterification to completion. Then the catalyst is neutralized and salts and impurities removed in a series of filtrations and washes. The molten DLTDP and DSTDP are converted to solid products by flaking and packaged. The liquid DTTDP product is drummed. The TDPN intermediate is made by reacting acrylonitrile and sodium sulfhydrate in aqueous solution. The resulting aqueous phase is split off, the product phase washed with water and the remaining TDPN used to make the thioesters. The reactions all take place in enclosed reactors, thus limiting potential worker exposure. The DLTDP, DTTDP and DSTDP all have very low vapor pressures at ambient temperatures so the risk of vapor contact during manufacture and drumming is relatively low. These chemicals are used by our customers who add them to variety of plastics such as polyethylene, polyolefins (mostly polypropylene), and polystyrene. Common use levels of DLTDP and DSTDP are 0.1 to 0.2 %. The polymers are then further processed into items such as washing machine agitators, battery cases, food packaging materials, and household appliances. .....
SALES SPECIFICATION

APPEARANCE

 White crystalline powder

ASSAY

97.0% min

SET POINT

 63 C min

COLOR, APHA

100 max

VOLATILE MATTER

0.5% max (at 100 C for 2 hrs)

ACID VALUE

0.1 max ( mg KOH/kg)

OH VALUE 10.0 max (( mg KOH/kg)

ASH CONTENT

0.01% max

TRANSPORTATION
PACKING  
HAZARD CLASS

Not regulated

UN NO.

 

OTHER INFORMATION