Caprolactam

• Hexahydro -2H- azepin- 2-one
• ε -caprolactam

White scales

Fixed

1.02 g · cm -3 ( 75 ° C)

70 ° C.

270 ° C

Readily soluble in water: 820 g · l-1 (20 ° C)

Attention

5 mg · m -3 ( inhalable aerosol fraction)

Template: Infobox chemical / molecular formula search available

Caprolactam, accurate ε -caprolactam, the raw material for the ring-opening polymerization of polyamide 6 ( Perlon). A second possibility for the polymerization is in the hydrolytic cleavage of the amide bond and subsequent polycondensation. Polyamide 6 is produced annually in the megaton scale.

Preparation of caprolactam

Of cyclohexanone is first prepared by reaction with the hydrogen sulfate or hydrochloride of hydroxylamine cyclohexanone. This is converted by a Beckmann rearrangement to ε -caprolactam. This often concentrated sulfuric acid is used as catalyst.

Properties of caprolactam

At room temperature, ε -caprolactam forms white crystals which are readily soluble and hygroscopic water. Caprolactam is therefore usually stored until use at temperatures above 80 ° C. When stronger heating of caprolactam it decomposes with the formation of, inter alia, ammonia and nitrogen oxides.

Preparation of Polyamide 6

Also known under the trade name Perlon polyamide 6 produced by ring-opening polymerization of ε -caprolactam. The time required to start the chain ω -aminocaproic acid (6- aminohexanoic acid ) is recovered from the hydrolytic ring-opening of ε -caprolactam.

This reacts with caprolactam to polycaprolactame or polyamide 6