diethenyl-Benzene polymer with ethenylbenzene
[CAS# 9003-70-7]

Identification

• Classification: Catalysts and additives >> Polymer
• Name: diethenyl-Benzene polymer with ethenylbenzene
• Synonyms: Polystyrene Resin; 1,2-Divinylbenzene - styrene (1:1)
• Molecular Formula: (C₁₀H₁₀)_x^.(C₈H₈)_x
• CAS Registry Number: 9003-70-7
• EC Number: 618-373-9
• SMILES: C=Cc1ccccc1.C=Cc1ccccc1C=C

Safety Data

• Hazard Symbols: GHS07 Warning
• Hazard Statements: H302-H315-H319-H335
• Precautionary Statements: P261-P301+P312-P302+P352-P304+P340-P305+P351+P338

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Eye irritation	Eye Irrit.	2	H319

Discovory and Applicatios

Diethenyl-benzene polymer with ethenylbenzene is a crosslinked polymeric material composed primarily of styrene (ethenylbenzene) and divinylbenzene (diethenylbenzene). This copolymer is commonly known in industrial and scientific contexts as polystyrene crosslinked with divinylbenzene, and it is widely used in the manufacture of ion exchange resins, solid-phase supports, and various porous materials due to its robust chemical and mechanical properties.

The origin of this copolymer traces back to the mid-20th century, when the utility of styrene-based polymers was being extensively explored for commercial and laboratory applications. Styrene, a monomer with a vinyl group attached to a benzene ring, can be polymerized through free-radical mechanisms to yield polystyrene, a thermoplastic resin known for its rigidity and clarity. However, linear polystyrene is often too soft and soluble for many demanding applications. To overcome this limitation, divinylbenzene, which contains two vinyl groups on a benzene ring, was introduced as a crosslinking agent.

The crosslinking of polystyrene chains by divinylbenzene creates a three-dimensional polymer network. This structure enhances the thermal and chemical stability of the material, while also imparting porosity and resistance to swelling in various solvents. The extent of crosslinking can be controlled during synthesis by adjusting the proportion of divinylbenzene to styrene. Typically, commercially available crosslinked polystyrene resins contain between 2% and 12% divinylbenzene by weight.

A key application of diethenyl-benzene polymer with ethenylbenzene is in ion exchange chromatography. The copolymer is sulfonated to produce cation exchange resins or aminated to form anion exchange resins. These resins are widely used in water softening, purification of drinking water, and the demineralization of industrial process water. In biotechnology and analytical chemistry, these materials serve in the separation and purification of proteins, peptides, and nucleic acids.

In solid-phase synthesis, especially in peptide synthesis, crosslinked polystyrene beads are used as a support matrix. The mechanical strength of the crosslinked network allows the beads to maintain their integrity during repeated washing and reaction cycles. Functional groups are introduced onto the bead surface or through spacer arms, providing anchoring points for growing molecular chains. After synthesis, the final product is cleaved from the solid support, which remains unchanged and can sometimes be reused.

Another important use is in solid-phase extraction (SPE) and chromatography as stationary phases. The hydrophobic and mechanically durable nature of crosslinked polystyrene makes it an excellent base for reversed-phase and normal-phase chromatographic separations. These stationary phases are also often modified with functional groups to tailor their selectivity for particular classes of analytes.

Crosslinked polystyrene-divinylbenzene matrices are also utilized in catalysis. Acidic or basic functional groups can be grafted onto the polymer to yield heterogeneous catalysts suitable for use in organic synthesis. Their solid nature allows for easy separation of the catalyst from the reaction mixture, reducing purification costs and improving operational convenience.

In environmental engineering, these polymers are used in sorption applications for removing organic pollutants from air and water. Due to their porosity and high surface area, they can adsorb volatile organic compounds (VOCs), pesticides, and other contaminants efficiently.

The synthesis of the copolymer is typically carried out through suspension polymerization. Styrene and divinylbenzene are dispersed in water in the presence of a stabilizer and an initiator, forming spherical beads. The polymerization is conducted at elevated temperatures, and the resulting beads can be washed, dried, and further functionalized as needed. Control over the bead size and porosity is critical for specific applications, especially in chromatography and ion exchange.

The material is generally chemically inert and exhibits excellent resistance to acids, bases, and organic solvents. However, it is sensitive to strong oxidizing agents and extreme thermal conditions. Handling of the monomers requires caution, as both styrene and divinylbenzene are volatile and may pose health risks upon inhalation or skin contact.

In summary, the copolymer of diethenyl-benzene with ethenylbenzene is a foundational material in many scientific and industrial processes. Its versatility, durability, and ease of modification make it indispensable in chromatography, ion exchange, catalysis, and solid-phase synthesis. Its continued utility reflects both its structural adaptability and the efficiency it brings to a wide range of chemical operations.