Bis[3-(triethoxysilyl)propyl] tetrasulfide | CAS No. 40372-72-3

Conquer Corrosion and Boost Bonding: Bis[3-(triethoxysilyl)propyl] Tetrasulfide (CAS No. 40372-72-3) from Pengrun Ltd.

Bis[3-(triethoxysilyl)propyl] tetrasulfide, also known as TESPTS or 3,3′-Tetrathiobis(propyl-triethoxysilane), is a bifunctional organosilane with the molecular formula C18H42O6S4Si2 and the CAS number 40372-72-3. It has a technical grade purity of ≥90% (NMR) and a molecular weight of 538.95. It is a liquid at room temperature with a density of 1.08 g/mL and a refractive index of 1.49.

TESPTS is widely used as a crosslinking agent and reinforcing filler in the manufacturing of rubber. It can form covalent bonds with both organic and inorganic substrates, such as rubber polymers and silica fillers, through its triethoxysilyl and tetrasulfide groups. This results in improved mechanical properties, such as tensile strength, elongation, abrasion resistance, and heat resistance, of the rubber products. TESPTS also enhances the dispersion and adhesion of silica fillers in rubber matrices, reducing the rolling resistance and improving the fuel efficiency of tires.

TESPTS can also provide corrosion protection to metallic substrates by forming a thin film on their surface. The film acts as a barrier against moisture, oxygen, and chloride ions, which are the main causes of corrosion. The film also has self-healing properties, as it can re-form covalent bonds with the metal after being damaged by mechanical or chemical stress.

TESPTS is also used as a precursor in the synthesis of mesoporous organosilicas, which are hybrid materials with tunable pore size, shape, and functionality. TESPTS can be co-condensed with other organosilanes or tetraethyl orthosilicate (TEOS) under acidic or basic conditions to form mesoporous organosilicas with various structures, such as hexagonal, cubic, lamellar, or wormlike. The tetrasulfide groups in TESPTS can act as functional sites for further modification or catalysis.

TESPTS is a versatile organosilane that can be used for various applications in rubber, metal, and mesoporous materials.

Technical parameters:

This product is a light yellow transparent liquid with a slight ethanol odor, soluble in ethanol, ketones, benzene, acetonitrile, dimethylformamide, dimethyl sulfoxide, chlorinated hydrocarbons, insoluble in water.

Light yellow to yellow transparent liquid in appearance.



  1. It is often used to treat carbon black, SiO2 and other inorganic fillers, not only has the role of activator and coupling agent,
  2. It also has the role of cross-linking agent, softener and reinforcing agent
  3. It is used as a reinforcing agent and vulcanizing agent in the rubberindustry.
  4. It can be used for natural rubber, isoprene rubber, styrene-butadiene rubber, butadiene rubber, butyl ester rubber, neoprene rubber, butyl rubber, halogenated butyl rubber, EPDM rubber and oil-filled rubber of these rubbers, which can also be used in the combined rubber of these rubbers.
  5. Applied to sulfurized rubber, it can improve crosslinking stability, tear resistance, shear resistance, water resistance, etc., and reduce compression deformation.
  6. Applicable inorganic fillers: carbon black, silica, glass fiber, talc, mica, fly ash, clay, etc.
  7. Suitable for rubber products, tires (tread, carcass, tire outer wall), solid rubber tire rubber roller surface. Conveyor belt surfaces, steel brush wire adhesives, cables (absolute and cladding), shoes (pullback shoes, marathon shoes, tennis shoes).

The functions are:

  1. Unvulcanized rubber material

(1) Reduce Mooney viscosity; (2) Reduce scorching; (3) Increase the degree of vulcanization; (4) The mixing, calendering and extrusion characteristics are greatly improved.

  1. Vulcanized rubber

(1) Increased tensile strength; (2) Increase the fixed extension strength; (3) Permanent deformation reduction; (4) Heat generation and dynamic characteristics are improved; (5) Silicon wear performance is improved: (6) tear strength is improved; (7) The swelling property in water and other substances is improved.

Packing: The finished product is packed in 5KG, 10KG, 25KG, 200KG plastic drum, other specifications need to be booked.

Product Code Si69
English Name: Bis[3-(triethoxysilyl)propyl]tetrasulfide
Alias: 3,3′-Bis(triethoxysilylpropyl)tetrasulfide;
A 1289;
B 2494;
Bis[3-(triethoxysilyl)propyl] tetrasulfide;
Bis[g-(triethoxysilyl)propyl] tetrasulfide;
Cabrus 4;
Degussa Si 69;
EF 60;
EF 60 (coupling agent);
KBE 846;
KBE 849;
KH 845-4;
MB 69;
SCA 98;
SIB 1825.0;
Si 29;
Si 69;
Silane 69;
Silquest A 1289;
TM 69;
Unisilan 41;
WD 40;
WD 40 (coupling agent);
Z 6940
Molecular formula: C18H42O6S4Si2
Molecular weight: 538.94
CAS Number: 40372-72-3
EINECS Registration Number: 254-896-5
Physicochemical properties
Refractive index: 1.49
Density: 1.08
Content(%) ≥22.5


In the arena of material science, conquering weaknesses and maximizing performance are constant pursuits. Bis[3-(triethoxysilyl)propyl] Tetrasulfide (CAS No. 40372-72-3), a multifaceted champion from Pengrun Ltd., emerges as a game-changer. This unique silane coupling agent harnesses the power of both silicon and sulfur to deliver exceptional benefits across diverse applications.

Dual Defense: Corrosion Shield and Bonding Booster:

Imagine a molecule with a split personality, offering both defensive and offensive capabilities. That’s the essence of Bis[3-(triethoxysilyl)propyl] Tetrasulfide. Its silane moiety forms strong covalent bonds with organic polymers like rubber and resins, while the sulfur groups create robust chemical bonds with various metals. This synergy unlocks two key superpowers:

Unmatched Corrosion Protection: The sulfur groups act as a formidable barrier, shielding metals from harsh environments like saltwater, acidic conditions, and oxidative stress. This translates to longer material lifespans, reduced maintenance costs, and enhanced product reliability.
Superior Adhesion Enhancement: The silane bonds bridge the gap between organic and inorganic materials, creating incredibly strong interfaces. This translates to improved adhesion in rubber blends, strengthened composites, and durable coatings, leading to better performance and longer-lasting functionality.
Beyond the Battlefield: A Universe of Applications:

The versatility of Bis[3-(triethoxysilyl)propyl] Tetrasulfide extends far beyond corrosion protection and adhesion promotion. Its prowess shines in numerous industries, including:

Rubber: It strengthens rubber compounds, enhances tear resistance, and improves abrasion performance, leading to longer-lasting tires, hoses, and seals.
Composites: As a crosslinker, it strengthens the bond between fiber reinforcements and resin matrices, resulting in high-performance composites with superior mechanical properties.
Coatings: It improves adhesion between coatings and substrates, leading to chip-resistant finishes, extended coating life, and enhanced weatherability.
Adhesives: It significantly improves the adhesion of adhesives to both organic and inorganic substrates, ensuring reliable and durable bonds for critical applications.

Pengrun Ltd.: Your Trusted Partner for Silane Solutions:

When it comes to quality and reliability, Pengrun Ltd. stands tall. Their commitment to stringent quality control and continuous innovation ensures you receive a consistently high-performing Bis[3-(triethoxysilyl)propyl] Tetrasulfide, backed by expert technical support.

Embrace the Power of Versatility:

With its dual-action power and diverse applications, Bis[3-(triethoxysilyl)propyl] Tetrasulfide from Pengrun Ltd. empowers you to:

Extend material lifespans and reduce maintenance costs.
Boost the performance and durability of your products.
Innovate and develop new material solutions with enhanced functionality.
Take the leap towards material mastery. Contact Pengrun Ltd. today and unlock the full potential of Bis[3-(triethoxysilyl)propyl] Tetrasulfide!

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