Product Overview
Vinylbenzyl Chloride (VBC, CAS 30030-25-2) is an important bifunctional aromatic monomer with the molecular formula C₉H₉Cl and a molecular weight of 152.62 g/mol. This compound uniquely contains both a polymerizable vinyl group and a highly reactive benzyl chloride moiety, a dual-functional structure that establishes it as an indispensable building block in polymer chemistry.
Commercially, Vinylbenzyl Chloride is typically supplied as a mixture of meta and para isomers, stabilized with 50–100 ppm of tert-butylcatechol (TBC) to prevent premature polymerization during storage. The product appears as a colorless to light yellow liquid, with purity specifications generally ≥95% to ≥97%. Key physical properties include: boiling point 229°C (lit.), density 1.074 g/mL (25°C), vapor pressure 1 mmHg (56.1°C), and flash point 101°C (closed cup).
The Bifunctional Structure: The Core Value of Vinylbenzyl Chloride
Vinylbenzyl Chloride's irreplaceable position in functional polymer applications stems from its unique molecular design.
The vinyl group provides a polymerizable active site, enabling Vinylbenzyl Chloride to participate in copolymerization reactions through various mechanisms—including free radical polymerization and RAFT polymerization—to form polymer backbones. The benzyl chloride moiety serves as a reactive "handle," allowing the introduction of diverse functional groups via nucleophilic substitution reactions after polymerization, including quaternization, phosphonation, thiolation, and pyridine functionalization.
This dual functionality fundamentally distinguishes Vinylbenzyl Chloride from ordinary styrene monomers: while styrene provides a polymerizable backbone, it lacks reactive sites for post-functionalization. It is precisely this "polymerization + post-functionalization" two-step design logic that makes Vinylbenzyl Chloride an ideal precursor for preparing ion exchange resins, functional coatings, and advanced functional materials.
Key Application Areas
1. Ion Exchange Resins — The Largest Application Market
Ion exchange membranes represent the largest application field for Vinylbenzyl Chloride. After copolymerization with styrene, Vinylbenzyl Chloride can introduce quaternary ammonium groups via the benzyl chloride moiety to produce strongly basic anion exchange resins. These resins play critical roles in water purification, sugar solution decolorization, uranium recovery, and electrodialysis processes.
Research has demonstrated that pyridine-functionalized hypercrosslinked resins, synthesized via Friedel-Crafts alkylation from divinylbenzene and Vinylbenzyl Chloride copolymer (DVB-co-VBC) precursors, exhibit excellent adsorption performance toward hexavalent chromium Cr(VI)—achieving a maximum adsorption capacity of 207 mg/g at pH=2 with an equilibrium time of only 4 minutes. This data fully illustrates the significant potential of Vinylbenzyl Chloride-based functional resins in heavy metal wastewater treatment.
2. Anion Exchange Membranes — Frontier Applications in the Energy Sector
In alkaline water electrolyzers and fuel cells, quaternized polymer anion exchange membranes based on Vinylbenzyl Chloride are receiving extensive attention. Researchers have developed polybenzimidazole-crosslinked poly(vinylbenzyl chloride) membranes, whose 1,4-diazabicyclo[2.2.2]octane (DABCO) quaternary ammonium groups impart excellent ion conductivity and chemical stability to the membrane materials.
3. Polymer Functionalization and Advanced Materials
As a functional monomer, Vinylbenzyl Chloride can be polymerized through various reversible deactivation radical polymerization (RDRP) techniques. Its benzyl chloride side groups are highly sensitive to nucleophiles, enabling efficient substitution reactions under mild conditions. This characteristic gives it broad applications in the following areas:
Formulation components in acrylic latex pressure-sensitive adhesives
Preparation of porous monolithic columns for chromatographic stationary phases
Magnetic hypercrosslinked polymers for solid-phase extraction
Synthesis of sulfur-vinylbenzyl chloride copolymers via inverse vulcanization
Safety and Compliance
Vinylbenzyl Chloride is classified as a hazardous chemical, and strict safety protocols must be followed during use, storage, and transportation.
Hazard Classification: Harmful if swallowed (H302); Toxic in contact with skin (H311); Toxic if inhaled (H331); Causes skin irritation (H315); May cause an allergic skin reaction (H317); Causes serious eye irritation (H319); Very toxic to aquatic life with long-lasting effects (H410).
Storage and Transport Requirements: UN number 2810, Class 6.1 toxic liquid, packing group III. Recommended storage temperature is 2–8°C or –20°C (under argon protection), away from heat and light. Operators should wear face shields, gloves, goggles, and ABEK-type respiratory protection.
Environmental Impact: Vinylbenzyl Chloride is highly toxic to aquatic organisms; special care must be taken to prevent its release into water bodies.
Market Outlook
The global Vinylbenzyl Chloride (4-Vinylbenzyl Chloride) market exhibits steady growth. The global market size was approximately USD 88.3 million in 2024 and is projected to reach USD 113 million by 2031, representing a compound annual growth rate (CAGR) of approximately 3.7%.
From a regional perspective, the Asia-Pacific region is the largest Vinylbenzyl Chloride market globally, accounting for over 65%. Major manufacturers include AGC, DOW, and Linchuan Chemical, with the top three companies collectively holding more than 95% of the market share. In terms of product type, mixed isomer products dominate, accounting for over 75% of the market.
Looking at downstream applications, ion exchange membranes represent the largest application segment, followed by chemical additives and photographic materials. With continued growth in global demand for water treatment, new energy (hydrogen energy, fuel cells), and functional polymer materials, the market outlook for Vinylbenzyl Chloride remains optimistic.
Conclusion
Vinylbenzyl Chloride (CAS 30030-25-2), with its unique vinyl + benzyl chloride dual-functional structure, demonstrates irreplaceable value in ion exchange resins, anion exchange membranes, functional polymers, and other fields. As a critical bridge connecting basic polymer backbones to advanced functionalization, Vinylbenzyl Chloride will continue to play an important role in strategic industries including water treatment, new energy, and functional materials. For professionals engaged in polymer synthesis, functional materials R&D, and related application fields, a thorough understanding of the properties and applications of Vinylbenzyl Chloride is an essential foundation for grasping the development direction of advanced functional materials.