Other Long-Chain Diols

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Besides the long-chain diols such as dodecanediol and diethylene glycol mentioned earlier, there are some less common straight-chain diols, described below.

1,7-Heptanediol (C7H16O2) has a molecular formula of C7H16O2 and a molecular weight of 132.2. Its CAS number is 629-30-1. It is produced in small batches by Tokyo Chemical Industry Co., Ltd., Japan, with a purity >98%.

1,8-Octanediol (C8H18O2) has a molecular formula of C8H18O2 and a molecular weight of 146.2. Its CAS number is 629-41-4. It is a white powder or flaky crystal with a melting point of 59–61°C and a boiling point of 172°C (2.67 kPa). It is soluble in ethanol but sparingly soluble in water, ether, and light gasoline. Used as an intermediate in cosmetics, plasticizers, specialty additives, and UV-cured coatings. Zibo Guangtong Chemical Co., Ltd. industrially produces 1,8-octanediol with a purity ≥98.0%.

1,9-Nonanediol (ND), with the molecular formula C9H20O2 and molecular weight 160, is a white solid with a freezing point of 46℃, a boiling point (1.33 kPa) of 166℃, a viscosity (60℃) of 33 mPa·s, a relative density (54℃) of 0.914, and a flash point (open cup) of 162℃. It is insoluble in water. Kuraray Co., Ltd. (Kuraray) and Zibo Guangtong Chemical Co., Ltd. industrially produce 1,9-nonanediol with a purity ≥98.0%. The LD50 for acute oral poisoning in rats is 3.4 g/kg.

Kuraray Co., Ltd. of Japan also supplies a mixed glycol under the brand name ND-15, which is a mixture of 80%–90% 2-methyl-1,8-octanediol [CAS No. 109359-36-6] and 10%–20% 1,9-nonanediol [CAS No. 3937-56-2]. Its molecular formula is C9H20O2, and its molecular weight is 160. It is a colorless, transparent liquid at room temperature. Its relative density (30°C) is 0.934, and its viscosity (20°C) is 267 mPa·s. The boiling point (1.33 kPa) of 2-methyl-1,8-octanediol is 159°C. Its freezing point is below -6°C, its flash point (open cup) is 155°C, and it is insoluble in water.

1,10-Decamethylene glycol (decane-1,10-diol) has the molecular formula C10H22O2 and a molecular weight of 174.28. Its CAS number is 112-47-0. It is a white crystalline or powdery substance with a melting point of 72–75°C, a boiling point of 297°C or 192°C (2.67 kPa), a relative density of approximately 1.08, and a flash point of 152°C. It is used in cosmetics, lubricants, plasticizers, and polyurethane chain extenders. Zibo Guangtong Chemical Co., Ltd. and Jarchem Industries, Inc. (USA) have industrial production facilities for it.

The above-mentioned long-chain glycols can be used as polyurethane chain extenders.