Copolymer synthesis
Attributed industrial references identify crotonic acid as a comonomer with vinyl acetate for coating and paper-sizing polymers. [3]
01
THE ESSENTIALS
Crotonic Acid in 30 Seconds
The carbon–carbon double bond lies between carbons 2 and 3. E geometry places the higher-priority carboxyl and methyl groups on opposite sides; the condensed drawing alone does not encode that geometry.
This profile covers E/trans crotonic acid, CAS 107-93-7. Unspecified crotonic acid and Z/cis isocrotonic acid require separate identity checks. [1] [3]
Safety at a glance — TCI C0416 identifies toxic skin contact, harmful ingestion and severe skin burns and eye damage. Sigma 113018 emphasizes serious eye damage; Cayman’s US SDS identifies corrosivity and harmful ingestion or inhalation. ICSC also warns of polymerization under UV light or moisture and violent reaction with strong bases or peroxides. Use the exact product’s instructions, rather than the least severe catalog classification. [4] [5] [6] [14]
Condensed connectivity schematic; see the specified stereochemical identity below. [1]
02
GO A LITTLE DEEPER
Understanding Crotonic Acid
THE SIMPLE EXPLANATION
The functional groups
The carbon–carbon double bond lies between carbons 2 and 3. E geometry places the higher-priority carboxyl and methyl groups on opposite sides; the condensed drawing alone does not encode that geometry. [1]
A LITTLE DEEPER
What the structure changes
Its alkene and carboxyl group support distinct chemical transformations. A trans molecular identity does not establish a quantitative geometric-purity specification, and titration cannot independently distinguish E from Z acid. [1] [12]
Technical detail Identity, dissociation & specification
The neutral free-acid formula, connectivity and specified geometric identity are distinct from a salt, ester, polymer or anhydride. Numeric pKa is not promoted where retrieved conditions or conflicting measurements remain insufficiently resolved. [1] [2] [4] [5] [6]
Acid–base reference values describe equilibria under specified conditions. They are not a substitute for a validated formulation or an assay on the purchased lot.
03
MAKE THE CONNECTION
How Crotonic Acid Compares
Similar names and functional groups do not mean interchangeable chemicals.
SIDE-BY-SIDE COMPARISON
Crotonic Acid vs Methacrylic Acid
Unsaturated aliphatic monocarboxylic acid
versusUnsaturated aliphatic monocarboxylic acid
Fixed comparison for this prototype. Acid selectors are disabled; additional comparisons are coming later.
| Property | Crotonic Acid | Methacrylic Acid |
|---|---|---|
| Molecular formula | C₄H₆O₂ [1] | C₄H₆O₂ [7] |
| Molecular weight | 86.09 g/mol [1] | 86.09 g/mol [7] |
| Carbon atoms | 4 [1] | 4 [7] |
| Carboxyl groups | 1 [1] | 1 [7] |
| Structure | CH₃–CH=CH–COOH|E / trans identity [1] | CH₂=C(CH₃)–COOH [7] |
| Chemical family | Unsaturated aliphatic monocarboxylic acid [1] | Unsaturated aliphatic monocarboxylic acid [7] |
| Identity focus | E / trans free acid [1] | Free acid [7] |
Chemical identities are compared here; supplier grades, concentrations, and stereochemical specifications are separate purchasing attributes. pKa values retain their stated conditions; no quantitative solubility ranking is implied. The structure schematic does not encode stereochemistry.
When Might You Choose One Instead of the Other?
Choose E-crotonic acid when the validated synthesis requires its connectivity and geometry. Choose methacrylic acid for the terminal-alkene alpha-methyl framework. Request an isomer test where the product’s chemical assay does not resolve geometric composition. [1] [3] [7]
Specified starting material
Crotonic Acid
Match CH₃–CH=CH–COOH|E / trans identity and the method’s required chemical form.
Methacrylic Acid
Match CH₂=C(CH₃)–COOH; verify the identity before substituting a related acid.
Before choosing: match the reaction or formulation, then verify the exact form, grade, assay basis, and impurities. These contexts do not establish suitability for an industrial or regulated application.
04
FROM STRUCTURE TO APPLICATION
What Is Crotonic Acid Used For?
Copolymer synthesis
Attributed industrial references identify crotonic acid as a comonomer with vinyl acetate for coating and paper-sizing polymers. These are downstream-polymer applications. [3]
Synthetic building block
Cayman identifies E-crotonic acid as a building block for small molecules and polymers. Research synthesis is an intermediate use, not proof of therapeutic activity or finished-product suitability. [6]
06
SOURCE WITH CONTEXT
Crotonic Acid Suppliers
Compare specific products and package options. Listings are not ranked recommendations.
3 suppliers · 3 products · 7 package listingsLatest supplier check: October 3, 2026
Package sizes stay grouped under the supplier product. Assay methods, product forms, and regional markets remain visible. All displayed products specify E/trans identity and CAS 107-93-7. A Wako product with unspecified CAS 3724-65-0 was excluded from this comparison. Cayman’s milligram packages and storage instructions are not equivalent to industrial-scale TCI or Sigma packages.
Scroll horizontally if needed. Supplier and package identity stay visible.
| Supplier | Product / Grade | Purity / Assay | Package Size | Public Price | Normalized Price | Documentation | Last Checked | Action |
|---|---|---|---|---|---|---|---|---|
| TCI AmericaCrotonic Acid | Named grade not statedC0416 · 25 gExplicit (2E) identity. NMR confirms structure; no quantitative E-isomer specification inferred. | GC: minimum 98.0% Neutralization titration: minimum 98.0% | 25 g | $44.00USD · US public price | Not comparedGrades, assay bases, or forms differ | Document notes: TCI America
| View Product: TCI America, C0416 · 25 g (opens new tab) | |
| Named grade not statedC0416 · 100 gExplicit (2E) identity. NMR confirms structure; no quantitative E-isomer specification inferred. | GC: minimum 98.0% Neutralization titration: minimum 98.0% | 100 g | $99.00USD · US public price | Not comparedGrades, assay bases, or forms differ | View Product: TCI America, C0416 · 100 g (opens new tab) | |||
| Sigma-Aldrich / MerckCrotonic Acid | Named grade not stated113018-500GExplicit trans identity; no quantitative geometric-purity specification stated. | 98%; assay method not stated | 500 g | $64.80USD · US public price | Not comparedGrades, assay bases, or forms differ | Document notes: Sigma-Aldrich / Merck
| View Product: Sigma-Aldrich / Merck, 113018-500G (opens new tab) | |
| Named grade not stated113018-3KGExplicit trans identity; no quantitative geometric-purity specification stated. | 98%; assay method not stated | 3 kg | $340.00USD · US public price | Not comparedGrades, assay bases, or forms differ | View Product: Sigma-Aldrich / Merck, 113018-3KG (opens new tab) | |||
| Cayman ChemicalCrotonic Acid | Research use; named grade not stated43903 · 10 mgExplicit 2E identity and stereochemical InChI. Research only; not human or veterinary use. Supplier storage −20 °C is distinct from room-temperature shipping. | ≥95%; assay method not stated | 10 mg | $39.00USD · US public dollar listing | Not comparedGrades, assay bases, or forms differ | Document notes: Cayman Chemical
| View Product: Cayman Chemical, 43903 · 10 mg (opens new tab) | |
| Research use; named grade not stated43903 · 25 mgExplicit 2E identity and stereochemical InChI. Research only; not human or veterinary use. Supplier storage −20 °C is distinct from room-temperature shipping. | ≥95%; assay method not stated | 25 mg | $53.00USD · US public dollar listing | Not comparedGrades, assay bases, or forms differ | View Product: Cayman Chemical, 43903 · 25 mg (opens new tab) | |||
| Research use; named grade not stated43903 · 50 mgExplicit 2E identity and stereochemical InChI. Research only; not human or veterinary use. Supplier storage −20 °C is distinct from room-temperature shipping. | ≥95%; assay method not stated | 50 mg | $87.00USD · US public dollar listing | Not comparedGrades, assay bases, or forms differ | View Product: Cayman Chemical, 43903 · 50 mg (opens new tab) |
TCI America
Crotonic Acid
Neutralization titration: minimum 98.0%
Named grade not stated
Explicit (2E) identity. NMR confirms structure; no quantitative E-isomer specification inferred.
25 g
C0416 · 25 g- Public price
- $44.00USD · US public price
- Normalized price
- Not comparedGrades, assay bases, or forms differ
100 g
C0416 · 100 g- Public price
- $99.00USD · US public price
- Normalized price
- Not comparedGrades, assay bases, or forms differ
Documentation
Document notes: TCI America
- A product-specific certificate retrieval option was visible; no lot certificate was reviewed. Open the product page and use its certificate section.
- A current regional SDS was not verified in this pass.
- Origin-document availability was not verified. Country of origin is unverified and is not inferred.
Last checked:
Sigma-Aldrich / Merck
Crotonic Acid
Named grade not stated
Explicit trans identity; no quantitative geometric-purity specification stated.
500 g
113018-500G- Public price
- $64.80USD · US public price
- Normalized price
- Not comparedGrades, assay bases, or forms differ
3 kg
113018-3KG- Public price
- $340.00USD · US public price
- Normalized price
- Not comparedGrades, assay bases, or forms differ
Documentation
Document notes: Sigma-Aldrich / Merck
- A product-specific certificate retrieval option was visible; no lot certificate was reviewed. Open the product page and use its certificate section.
- A current regional SDS was not verified in this pass.
- Origin-document availability was not verified. Country of origin is unverified and is not inferred.
Last checked:
Cayman Chemical
Crotonic Acid
Research use; named grade not stated
Explicit 2E identity and stereochemical InChI. Research only; not human or veterinary use. Supplier storage −20 °C is distinct from room-temperature shipping.
10 mg
43903 · 10 mg- Public price
- $39.00USD · US public dollar listing
- Normalized price
- Not comparedGrades, assay bases, or forms differ
25 mg
43903 · 25 mg- Public price
- $53.00USD · US public dollar listing
- Normalized price
- Not comparedGrades, assay bases, or forms differ
50 mg
43903 · 50 mg- Public price
- $87.00USD · US public dollar listing
- Normalized price
- Not comparedGrades, assay bases, or forms differ
Documentation
Document notes: Cayman Chemical
- A product-specific certificate retrieval option was visible; no lot certificate was reviewed. Open the product page and use its certificate section.
- The linked SDS was retrieved for this product. Read its stated jurisdiction and obtain the applicable current local version.
- Origin-document availability was not verified. Country of origin is unverified and is not inferred.
Last checked:
Documentation evidence
COA = Certificate of Analysis · SDS = Safety Data Sheet · COO = Certificate of Origin.
Lookup means a retrieval option was visible, not that a lot certificate was reviewed. Check supplier means availability or the applicable document was not verified.
Prices may vary by quantity, account, contract, geography, and availability. These products have different grades, assay bases, or forms; no normalized comparison is shown. Foreign-market prices are reference listings only. No currency conversion, mass-to-volume conversion, or ranking is applied. Confirm equivalent specifications and a current quote before comparison. [4] [5] [6]
Verification limits & placement policy
pKa: CONFLICT UNRESOLVED. Compiled values include 4.17 at 18 °C, 4.69 without conditions, Ka 2.0×10⁻⁵ at 25 °C and pKa 4.817 at 25 °C. Isomer and measurement differences were not resolved; numeric pKa omitted. Water solubility: CONFLICT UNRESOLVED. TCI lists 76 g/L at 20 °C; HSDB cites 86 g/L at 25 °C and 555 g/L at 20 °C. Temperature does not explain the same-temperature discrepancy. Numeric main field omitted. Boiling point: CONFLICT UNRESOLVED. HSDB trans reference 185 °C at 760 mmHg; Sigma 180–181 °C without pressure; ICSC 189 °C without pressure. No matched method explains the spread. Numeric main field omitted. Density: OMITTED. Compiled records include molten-trans density at 77 °C and cis-isomer liquid density at 20 °C. Neither is a density for the E solid at 20 °C. CAS / geometry: VERIFIED. ICSC distinguishes E acid 107-93-7, unspecified 3724-65-0 and Z acid 503-64-0. No equivalence is inferred from a familiar name.
Only the displayed identity, specification, packages, public prices and stated documentation evidence were reviewed. Current stock, lead times, shipping eligibility, contract pricing, lot certificates, and regulatory suitability are unverified.
There are no paid placements. Future paid listings will show “Sponsored” in both views; payment will not determine chemistry interpretation or imply a ranking.
07
PLAN A LARGER ORDER
Need Crotonic Acid in Bulk?
Turn your requirements into a clear supplier brief.
Bulk RFQ feature — coming soon. Prototype form: submissions are not currently sent to suppliers. Use sample details to prepare an on-screen brief.
Prepare a bulk request Prototype form
08
A BUYER’S CHECKLIST
Before You Buy Crotonic Acid
Selections remain only while this page is open.
09
FOR YOUR REFERENCE
Crotonic Acid Technical Reference
Identity, product reference properties, and handling context.
Identification Names, formula & identifiers
- Principal CAS
- 107-93-7
- Identity focus
- E / trans free acid
- Formula
- C₄H₆O₂
- Molecular weight
- 86.09 g/mol
- IUPAC name
- (E)-but-2-enoic acid
- Connectivity SMILES
- CC=CC(=O)O
- Identity SMILES
- C/C=C/C(=O)O
- InChI
- InChI=1S/C4H6O2/c1-2-3-4(5)6/h2-3H,1H3,(H,5,6)/b3-2+
- PubChem CID
- 637090
Connectivity SMILES describes connectivity; it is not an independent stereochemical assignment. CAS and product-form distinctions are supported by the supplier listings. [1] [4] [5] [6]
Physical Properties Product references & conditions
Solid at 20 °C. Cis-isomer liquid-density and boiling records in compiled databases are excluded from this E-acid reference. [13] [4] [5]
- Melting specification
- TCI C0416: 71–73 °C; product specification [4]
Hydrate, concentration, stereoisomer, and temperature can change the relevant specification. Product reference data are not a reviewed lot certificate.
Acid/Base Properties Verified values & missing data
A numeric pKa was not verified for the selected identity in this review; no value is inferred. [2]
pKa: CONFLICT UNRESOLVED. Compiled values include 4.17 at 18 °C, 4.69 without conditions, Ka 2.0×10⁻⁵ at 25 °C and pKa 4.817 at 25 °C. Isomer and measurement differences were not resolved; numeric pKa omitted. Water solubility: CONFLICT UNRESOLVED. TCI lists 76 g/L at 20 °C; HSDB cites 86 g/L at 25 °C and 555 g/L at 20 °C. Temperature does not explain the same-temperature discrepancy. Numeric main field omitted. Boiling point: CONFLICT UNRESOLVED. HSDB trans reference 185 °C at 760 mmHg; Sigma 180–181 °C without pressure; ICSC 189 °C without pressure. No matched method explains the spread. Numeric main field omitted. Density: OMITTED. Compiled records include molten-trans density at 77 °C and cis-isomer liquid density at 20 °C. Neither is a density for the E solid at 20 °C. CAS / geometry: VERIFIED. ICSC distinguishes E acid 107-93-7, unspecified 3724-65-0 and Z acid 503-64-0. No equivalence is inferred from a familiar name.
Temperature, ionic strength, and the use of activities versus concentrations matter in quantitative work. These reference values are not buffer recipes.
Safety at a Glance Product-specific hazards
TCI C0416 identifies toxic skin contact, harmful ingestion and severe skin burns and eye damage. Sigma 113018 emphasizes serious eye damage; Cayman’s US SDS identifies corrosivity and harmful ingestion or inhalation. ICSC also warns of polymerization under UV light or moisture and violent reaction with strong bases or peroxides. Use the exact product’s instructions, rather than the least severe catalog classification. [4] [5] [6] [14]
Hazard classifications can vary by concentration, product, supplier and jurisdiction. Review the SDS for the exact product before handling. This summary does not replace the SDS.
Supplier safety information and SDS retrieval (opens new tab) · Cayman Chemical SDS PDF · exact product (opens new tab)
A product-page safety classification is not verification of every regional SDS. Confirm product code, chemical form and current local document.
Review supplier documentation10
COMMON QUESTIONS
Crotonic Acid FAQ
What distinguishes Crotonic Acid?
The carbon–carbon double bond lies between carbons 2 and 3. E geometry places the higher-priority carboxyl and methyl groups on opposite sides; the condensed drawing alone does not encode that geometry. [1]
How does it differ from Methacrylic Acid?
Crotonic and methacrylic acids both have formula C₄H₆O₂. Crotonic acid has an internal E alkene; methacrylic acid has an alpha-methyl terminal alkene. Formula or molecular weight alone cannot select the correct raw material. [7]
What must a buyer specify?
All displayed products specify E/trans identity and CAS 107-93-7. A Wako product with unspecified CAS 3724-65-0 was excluded from this comparison. Cayman’s milligram packages and storage instructions are not equivalent to industrial-scale TCI or Sigma packages. [4]
Are the listed products directly price-comparable?
No. The table retains differing grades, assay bases, forms, and markets. No normalized ranking or currency conversion is applied. [5]
What reference data still need checking?
pKa: CONFLICT UNRESOLVED. Compiled values include 4.17 at 18 °C, 4.69 without conditions, Ka 2.0×10⁻⁵ at 25 °C and pKa 4.817 at 25 °C. Isomer and measurement differences were not resolved; numeric pKa omitted. Water solubility: CONFLICT UNRESOLVED. TCI lists 76 g/L at 20 °C; HSDB cites 86 g/L at 25 °C and 555 g/L at 20 °C. Temperature does not explain the same-temperature discrepancy. Numeric main field omitted. Boiling point: CONFLICT UNRESOLVED. HSDB trans reference 185 °C at 760 mmHg; Sigma 180–181 °C without pressure; ICSC 189 °C without pressure. No matched method explains the spread. Numeric main field omitted. Density: OMITTED. Compiled records include molten-trans density at 77 °C and cis-isomer liquid density at 20 °C. Neither is a density for the E solid at 20 °C. CAS / geometry: VERIFIED. ICSC distinguishes E acid 107-93-7, unspecified 3724-65-0 and Z acid 503-64-0. No equivalence is inferred from a familiar name.
Can I request a bulk quote here?
The RFQ is a prototype that prepares an on-screen brief. Nothing is sent to suppliers. Confirm actual bulk terms directly with the supplier.
11
TRACE THE INFORMATION
Sources & Editorial Notes
Identity and compiled reference values are separated from supplier-specific specifications. Structural comparisons and buyer guidance are editorial interpretation. Sources were checked October 3, 2026; supplier information can change.
- PubChem · chemical identity (opens new tab)
Neutral molecular identity verified independently through PUG REST; CAS also checked on all selected supplier products.
- PubChem / HSDB · dissociation references (opens new tab)
No numeric field promoted: insufficient conditions or unresolved conflicting records.
- PubChem / HSDB · application references (opens new tab)
Attributed application records reviewed claim by claim. Free acid, intermediate, derivative and biological context are distinguished.
- TCI America · commercial product (opens new tab)
Direct product checked October 3, 2026. Identity, listed assay methods, packages, market, prices and documentation interfaces inspected. Lot certificates and stock are not verified.
- Sigma-Aldrich / Merck · commercial product (opens new tab)
Direct product checked October 3, 2026. Identity, listed assay methods, packages, market, prices and documentation interfaces inspected. Lot certificates and stock are not verified.
- Cayman Chemical · commercial product (opens new tab)
Direct product checked October 3, 2026. Identity, listed assay methods, packages, market, prices and documentation interfaces inspected. Lot certificates and stock are not verified.
- Methacrylic Acid · identity (opens new tab)
Primary structural comparison. Practical interpretation does not establish suitability.
- Acrylic Acid · identity (opens new tab)
Related identity and structural relationship.
- Butyric Acid · identity (opens new tab)
Related identity and structural relationship.
- Sorbic Acid · identity (opens new tab)
Related identity and structural relationship.
- Methacrylic Acid · dissociation references (opens new tab)
Only independently reviewed values are promoted into the comparison; no condition-free acidity ranking.
- OpenStax · Carboxylic-acid structure and properties (opens new tab)
General carboxylate resonance, acidity and structural interpretation; not authority for this acid’s quantitative constants.
- PubChem / HSDB · attributed physical references (opens new tab)
Conditions, isomer assignments, decomposition qualifiers and unresolved conflicts reviewed; no aggregate number treated as universal.
- ILO/WHO · ICSC 0423 (opens new tab)
Chemical-specific safety and physical context; exact-product SDS remains necessary.
Review limits
pKa: CONFLICT UNRESOLVED. Compiled values include 4.17 at 18 °C, 4.69 without conditions, Ka 2.0×10⁻⁵ at 25 °C and pKa 4.817 at 25 °C. Isomer and measurement differences were not resolved; numeric pKa omitted. Water solubility: CONFLICT UNRESOLVED. TCI lists 76 g/L at 20 °C; HSDB cites 86 g/L at 25 °C and 555 g/L at 20 °C. Temperature does not explain the same-temperature discrepancy. Numeric main field omitted. Boiling point: CONFLICT UNRESOLVED. HSDB trans reference 185 °C at 760 mmHg; Sigma 180–181 °C without pressure; ICSC 189 °C without pressure. No matched method explains the spread. Numeric main field omitted. Density: OMITTED. Compiled records include molten-trans density at 77 °C and cis-isomer liquid density at 20 °C. Neither is a density for the E solid at 20 °C. CAS / geometry: VERIFIED. ICSC distinguishes E acid 107-93-7, unspecified 3724-65-0 and Z acid 503-64-0. No equivalence is inferred from a familiar name.
This informational prototype is not a supplier, quotation service, or endorsement of a product’s fitness for an application. Buyers should verify the applicable specification, certification, and regulatory requirements for their intended use.