Isophthalic acid (CAS 121-91-5) — formula C8H6O4, molecular weight 166.13; category organic chemicals.
Isophthalic acid (CAS 121-91-5) is a chemical raw material in the organic chemicals category. Its molecular formula C8H6O4 comprises 8 C, 6 H, 4 O atoms. Its molecular weight is about 166.13. Reported physicochemical data: melting point around 653 °F (USCG, 1999), LogP about log Kow = 1.66. As a sourcing and distribution partner we help locate and compare this item across domestic and cross-border channels, arranging samples and batch orders with full COA and compliance files.
| CAS Number | 121-91-5 |
|---|---|
| Molecular Formula | C8H6O4 |
| Molecular Weight | 166.13 |
| Melting Point | 653 °F (USCG, 1999) |
| LogP | log Kow = 1.66 |
| Applications | Used to make plastics, unsaturated polyester resins, alkyd resins, polyamides, and thermoplastic polyesters, co-monomer with terephthalic acid to make plastic bottles and specialty resins |
| Category | Organic Chemicals |
Documented applications: Used to make plastics, unsaturated polyester resins, alkyd resins, polyamides, and thermoplastic polyesters, co-monomer with terephthalic acid to make plastic bottles and specialty resins.
Isophthalic acid is a carbon-based organic compound with CAS registry number 121-91-5 and molecular formula C8H6O4 (molecular weight 166.13), belonging to the organic chemicals segment of chemical raw materials.
CAS number: 121-91-5
Its molecular formula C8H6O4 comprises 8 C, 6 H, 4 O atoms.
Also known as: Isophthalic acid · 间苯二甲酸
Category: organic chemicals
The CAS registry number of Isophthalic acid is 121-91-5.
Molecular formula C8H6O4, molecular weight 166.13.
It is also registered under: Isophthalic acid, 间苯二甲酸.
Recorded applications: Used to make plastics, unsaturated polyester resins, alkyd resins, polyamides, and thermoplastic polyesters, co-monomer with terephthalic acid to make plastic bottles and specialty resins.
Category: Organic Chemicals.
Packaging is agreed per order, from lab-scale packs to bulk, and confirmed with each order rather than fixed on the page. A Certificate of Analysis (COA) ships with every batch and MSDS is available; where the end use carries a regulatory limit (food contact, pharmaceutical or cosmetic), state the standard at enquiry and the grade is set against it.
Independent reference data for Isophthalic acid (CAS 121-91-5), compiled from public chemistry databases.
| CAS Registry Number | 121-91-5 |
|---|---|
| PubChem CID | 8496 |
| Molecular formula | C8H6O4 |
| IUPAC name | benzene-1,3-dicarboxylic acid |
| UNII (FDA) | X35216H9FJ |
| Molecular Weight | 166.13 |
|---|---|
| XLogP3 | 1.7 |
| Hydrogen Bond Donor Count | 2 |
| Hydrogen Bond Acceptor Count | 4 |
| Rotatable Bond Count | 2 |
| Exact Mass | 166.02660867 |
| Monoisotopic Mass | 166.02660867 |
| Topological Polar Surface Area | 74.6 |
| Heavy Atom Count | 12 |
| Melting Point | 653 °F (USCG, 1999) |
|---|---|
| Melting Point | 347 °C |
| Melting Point | 345-348 °C |
| Density | 1.53 at 4 °C |
| Density | 1.507 @ 20°C |
| Vapor Pressure | 0.00000002 [mmHg] |
| Vapor Pressure | VP: 0.009 Pa (0.0675 mm Hg) at 100 °C |
| Vapor Pressure | 0.068 [mm Hg] @100 °C |
| LogP | log Kow = 1.66 |
| LogP | 1.66 |
ISOPHTHALIC ACID; 121-91-5; Benzene-1,3-dicarboxylic acid; 1,3-Benzenedicarboxylic acid; m-Phthalic acid; m-Benzenedicarboxylic acid; Acide isophtalique; Kyselina isoftalova; DTXSID3021485; X35216H9FJ; NSC-15310; DTXCID301485; CHEBI:30802; benzene-1,3-dicarboxylate;hydron; RefChem:7642; 204-506-4
| Regulatory & Food Contact | FDA Cumulative Estimated Daily Intake (CEDI): FCS FDA Inventory of Food Contact Substances Listed in 21 CFR: FCS FDA Inventory of Effective Food Contact Substance (FCS) Noti: FCS Isophthalic acid (CAS Reg. No. 121-91-5) As a monomer in the manufacture of ethylene terephthalate-isophthalate copolymers. As a monomer in the manufacture of ethylene terephthalate-isophthalate copolymers, except for use in contact w |
|---|---|
| GHS notification summary | 91% (614 / 675) |
| GHS notification summary | 91% (614 / 675) |
|---|
This chemical does not meet GHS hazard criteria for 91% (614 of 675) of all reports.
Reported as not meeting GHS hazard criteria by 614 of 675 companies (only 9% companies provided GHS information). For more detailed information, please visit ECHA C&L website.
Isophthalic acid · CAS 121-91-5 · C8H6O4. UNII X35216H9FJ. Melting Point: 653 °F (USCG, 1999); Melting Point: 347 °C; Melting Point: 345-348 °C.
Source: PubChem / Wikidata; the batch COA governs where values differ.
Supplier: Jinan Shenghe Chemical Co., Ltd.
中文页面: 间苯二甲酸