Chemical name: Vinylbenzyl chloride (mixed isomers)
Synonyms: VBC, CMS, CMS-P, Chloromethylstyrene, 4-Chloromethylstyrene (para-isomer)
CAS: 30030-25-2
Molecular formula: C9H9Cl
Specification / COA:
| Item | Standard | COA |
| Appearance | Light yellow to colorless liquid | Complies |
| Vinylbenzyl chloride (GC) | ≥97% | 98.10% |
| Ortho isomer | — | 16.94% |
| Meta isomer | — | 3.97% |
| Para isomer | — | ~77.19% |
| Single bromine compound | ≤1% GC | Complies |
| Other single impurity | ≤2% GC | Complies |
| Inhibitor (TBC) | 500 PPM | Complies |
Usage:
- PPO/PPE oligomer end-capping for high-frequency CCL: The benzylic chloride group of VBC reacts selectively with the terminal phenolic hydroxyl groups of poly(2,6-dimethyl-1,4-phenylene ether) (PPO/PPE) oligomers, introducing vinyl benzyl ether (VBE) end groups. These vinyl-terminated PPO oligomers crosslink via radical or thermal curing to yield thermoset resins with dielectric constant (Dk) below 3.0 and loss tangent (Df) below 0.005 at 10 GHz — enabling high-frequency copper-clad laminates (CCL) for 5G infrastructure, millimetre-wave antenna substrates, and AI accelerator boards
- Strong-base anion exchange resins: VBC copolymerised with divinylbenzene (DVB) produces a chloromethylated polymer scaffold. Quaternisation with trimethylamine introduces type-I quaternary ammonium groups, yielding strong-base anion exchange resins for water demineralisation, pharmaceutical-grade purification, and continuous-flow chemical processing
- Photoresist and advanced lithography polymers: The reactive chloromethyl group serves as an attachment point for chromophores, photoactive compounds, and spacer arms on polystyrene-type backbones, enabling fine-pitch patterning in semiconductor wafer fabrication and flat-panel display manufacturing
- Ion-conducting membranes: Quaternary ammonium or phosphonium groups introduced via VBC functionalisation produce anion exchange membranes (AEM) used in alkaline fuel cells, electrodialysis units, and CO2 electroreduction systems, where hydroxide conductivity and chemical stability are critical
- Cross-linkable functional polymers and coatings: VBC’s dual functionality — polymerisable vinyl and reactive benzylic chloride — allows simultaneous chain growth and side-chain derivatisation. Applications include anti-static coatings, bioconjugation scaffolds, and specialty polymers incorporating azide, thiol, or sulfonate groups
- Coupling agents and adhesion promoters: The chloromethyl group undergoes nucleophilic substitution with silanol-terminated surfaces, forming covalent linkages between polymer matrices and glass or inorganic fillers in composite laminate systems
Packing: 200 kg per HDPE drum or IBC tote; 25 kg jerrycans available on request. Shipped with inhibitor (TBC 500 PPM) to prevent polymerisation during storage and transit.
Storage: Store in a cool (below 25 degrees C), dry, well-ventilated area away from heat sources, direct sunlight, and oxidising agents. Keep containers tightly sealed; inhibitor level should be confirmed before use. Recommended shelf life: 6 months from manufacturing date when stored under recommended conditions.
Related Products
Further Reading: Vinylbenzyl Chloride (VBC/CMS): Applications in 5G CCL, Ion Exchange Resins, and Green Hydrogen
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Vinylbenzyl chloride (VBC), commercially known as CMS or CMS-P, is a bifunctional reactive monomer featuring a polymerisable styrenic vinyl group and a highly reactive benzylic chloride substituent on the same benzene ring. The mixed-isomer grade (CAS 30030-25-2) typically comprises over 75% para isomer with ortho and meta fractions, providing optimal reactivity for end-capping reactions while remaining a stable liquid at ambient temperature. Its defining industrial application is the end-capping of low-molecular-weight PPO/PPE oligomers: the chloromethyl group undergoes etherification with terminal phenolic hydroxyls under mild base catalysis, converting the oligomer chain ends to vinyl benzyl ether (VBE) groups. These VBE-capped PPO resins cure into tightly crosslinked thermoset networks that deliver dielectric constants (Dk) below 3.0 and dissipation factors (Df) below 0.005 at 10 GHz — benchmark values demanded by next-generation CCL materials for 5G millimetre-wave base stations, automotive ADAS radar, and high-speed AI server boards. In the ion exchange field, VBC/DVB copolymers provide the reactive scaffold for type-I strong-base anion exchangers, prized for chemical stability and high exchange capacity. Unifarm Chemical supplies VBC at ≥97% purity (98.10% typical by GC) with full isomer composition data, TBC inhibitor level confirmation, and batch COA issued by the manufacturer.