Tolidine diisocyanate TODI / 3,3′-Dimethyl-4,4′-biphenylene diisocyanate CAS NO. 91-97-4

Short Description:

Chemical Name: 3,3′-Dimethyl-4,4′-biphenylene diisocyanate

Synonyms: 3,3′-Dimethyl-4,4′-biphenylene diisocyanate; Bitolylene Diisocyanate; benzoxadiazole; 4,4′-Diisocyanato-3,3′-dimethylbiphenyl;Tolidine diisocyanate (TODI)

Code: TODI

CAS No.: 91-97-4

Product Detail

Product Tags

Product Description

TODI / 3,3'-Dimethyl-4,4'-biphenylene diisocyanate, CAS number 91-97-4, is an universal additive for improving mechanical and chemical properties on urethane elastomers. The two benzene rings in the TODI molecule have a symmetrical structure. Due to the steric hindrance of the o-methyl group, the reaction activity is lower than that of TDI and MDI.

Comparing to NDI-based polyurethane elastomers, elastomers based on TODI, oligomer polyols and MOCA have similar physical properties, such as excellent heat resistance, hydrolysis resistance and mechanical properties. Comparing with rubbers, plastics and metals, TODI-based elastomers have much more advantages, they are durable, heat resistance and hydrolysis resistance. TODI-based elastomers offer superior mechanical properties to be applied on working under harsh conditions and/or environment. Furthermore, resulting from its longer pot life, TODI-based prepolymer is easier to handle in comparison to NDI-based products.


With its outstanding mechanical and chemical properties, TODI-based elastomers are widely applied on various fields. First of all, sealing components, such as oil sealing, piston ring, water seals and so on. Then, automobile parts are another major application of TODI, including bumper extensions, shock absorbers, grills and etc. Besides, high-ended industrial usage, i.e. belts, rolls, casters. Furthermore, TODI is an important coating agent in electric field and as artificial organs in medical equipment.

Packing & Storage

Packing: 50kgs/iron drum.

Storage and transportation: TODI is sensitive to moisture. Water reacts with all diisocyanates to form insoluble urea derivatives. TODI should be stored in tightly sealed containers in cool and dry conditions.

Do NOT put TODI along with food and avoid exposing in an environment above 30℃. After using, the lid must be sealed immediately in case of dysfunction. Under suitable storage conditions, TODI is valid for six months at least with effect from the date on which it’s delivered.



3,3'-Dimethyl-4,4'-biphenylene diisocyanate 



Batch No

2300405 Packing 20kg/drum Quantity 500kgs
Date of manufacturing 2023-04-05 Date of Expire 2024-04-04





Light yellow to white Granular solid


Total chlorine,% 



Hydrolyzed chlorine,%



Melting point, ℃

69 - 71

69.1 - 70.2

-NCO Content, %

31.5 - 32.5







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