Ethylstyrene (mixed isomers)
[CAS# 28106-30-1]

Identification

• Classification: Chemical reagent >> Organic reagent >> Olefins (cyclic and non-cyclic)
• Name: Ethylstyrene (mixed isomers)
• Synonyms: 1-ethenyl-2-ethylbenzene
• Molecular Formula: C₁₀H₁₂
• Molecular Weight: 132.20
• CAS Registry Number: 28106-30-1
• EC Number: 248-846-1
• SMILES: CCC1=CC=CC=C1C=C

Properties

• Density: 0.9±0.1 g/cm³, Calc.^*
• Index of Refraction: 1.543, Calc.^*
• Boiling Point: 192.3±10.0 ºC (760 mmHg), Calc.^*
• Flash Point: 62.1±7.6 ºC, Calc.^*

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

Safety Data

• Hazard Symbols: GHS05;GHS07;GHS09 Danger
• Hazard Statements: H302-H315-H318-H319-H335
• Precautionary Statements: P261-P264-P264+P265-P270-P271-P280-P301+P317-P302+P352-P304+P340-P305+P351+P338-P305+P354+P338-P317-P319-P321-P330-P332+P317-P337+P317-P362+P364-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin irritation	Skin Irrit.	2	H315
Eye irritation	Eye Irrit.	2	H319
Chronic hazardous to the aquatic environment	Aquatic Chronic	2	H411
Specific target organ toxicity - single exposure	STOT SE	3	H335
Acute toxicity	Acute Tox.	4	H302
Serious eye damage	Eye Dam.	1	H318

Discovory and Applicatios

Ethylstyrene (mixed isomers) refers to a mixture of positional isomers of ethyl-substituted styrene, primarily including 1-ethyl-2-vinylbenzene (ortho-ethylstyrene), 1-ethyl-3-vinylbenzene (meta-ethylstyrene), and 1-ethyl-4-vinylbenzene (para-ethylstyrene). These compounds share the molecular formula C10H12 and consist of a styrene backbone with an ethyl group substituted on the aromatic ring. The mixed isomer form is typically used in industrial applications where the precise isomeric composition is less critical.

Ethylstyrenes are generally produced by the alkylation of styrene or via dehydrogenation of the corresponding ethyl-substituted ethylbenzenes. The synthesis is commonly carried out using Friedel–Crafts alkylation or related electrophilic aromatic substitution methods, with subsequent separation depending on the desired isomeric distribution.

One of the main applications of ethylstyrene (mixed isomers) is as a comonomer in the production of styrenic polymers. When polymerized with styrene or other monomers, ethylstyrene imparts modified physical properties such as improved impact resistance, thermal stability, and mechanical performance. The ethyl substituent on the phenyl ring influences the polymer chain packing and flexibility, which can be advantageous in specific engineering plastic formulations.

Ethylstyrene is also used in the manufacture of specialty resins and coatings. Its incorporation into polymer matrices enhances chemical resistance and adhesion, which is beneficial in surface treatments, adhesives, and industrial protective coatings. The meta and para isomers are more frequently utilized in these settings due to their more favorable steric profiles during polymerization reactions.

In addition to polymer applications, ethylstyrene can serve as an intermediate in organic synthesis. It provides a functional vinyl group that participates in addition reactions, cross-coupling, and other transformations relevant to the construction of more complex molecular architectures.

Occupational and environmental safety measures are necessary during the handling of ethylstyrene due to its volatility and flammability. Exposure control and proper ventilation are recommended in industrial settings. While the compound is structurally related to styrene, toxicological assessments are typically conducted separately due to differences in substitution patterns that can affect metabolic behavior and environmental fate.

Ethylstyrene (mixed isomers) remains an established industrial chemical with recognized roles in polymer production and materials formulation, valued for its reactivity, compatibility with other monomers, and the tunability of its physical properties.

References

2023. Previous successes and untapped potential of pyrolysis-GC/MS for the analysis of plastic pollution. Analytical and Bioanalytical Chemistry, 415(12).
DOI: 10.1007/s00216-023-04671-1

2020. Polymeric Heterogeneous Catalysts in the Hydroformylation of Unsaturated Compounds. Petroleum Chemistry, 60(11).
DOI: 10.1134/s0965544121010011

2019. Synthesis of gem-dichlorocyclopropane and 1,3-dioxane derivatives from divinylbenzene. Russian Chemical Bulletin, 68(11).
DOI: 10.1007/s11172-019-2671-4