Ethylenediamine - adipic acid polymer

Add 40 ml. of ethyl alcohol to 21-5 g. of 70 per cent, ethylenediamine solution (0 25 mol) dissolve 36 5 g. of adipic acid (0 25 mol) in 60 ml. of a 6 1 mixture of ethyl alcohol and water. Mix the two solutions, stir and cool. Filter off the resulting salt and recrystaUise it from 60 ml. of a 6 1 ethyl alcohol - water mixture, and dry the salt in the air. Heat the salt in an atmosphere of oxygen-free nitrogen or of carbon dioxide in an oil bath until it melts (ca. 160°) the product wiU solidify after a short time. Reduce the pressure to 16 mm. of mercury or less and raise the temperature of the oil bath until the product remelts (about 290°) and continue the heating for 4-5 hours. Upon cooling, a nylon type polymer is obtained. 

DEPOLYMERISATION OF A HEXAMETHYLENE-DIAMINE-ADIPIC ACID POLYMER (NYLON 66 ) 

Add 10 ml. of concentrated sulphuric acid cautiously to 45 ml. of water contained in a 200 ml. round-bottomed flask, introduce 3 g. of Nylon 66 polymer into the hot solution, and heat under reflux for 6 hours. Allow to stand for 1 hour and cool in ice for a further hour. Filter off the solid and keep the filtrate. RecrystaUise the solid (adipic acid) from water m.p. 162°. 

Neutralise about one third of the filtrate witii 5N sodium hydroxide and add a further 2 ml. of the alkali solution. Add 1 ml. of benzoyl chloride and stir until the odour of the acid chloride disappears. Collet the solid by suction filtration, wash it with water until free from alkali, and then recrystaUise it from dilute alcohol. The product is the diben-zoyl derivative of hexamethylenediamine and melts at 159°. 

---

Ethyl n-propylmalonate, 486 Ethyl n-propyl ketone, 340 4-Ethylpyridine, 844 Ethyl 2-pyridylacetate, 931, 932 Ethyl salicylate, 783 Ethyl sulphite, 304 Ethyl -valerate, 382, 389 Ethyl vinylacetate, 382, 389 Ethylenediamine-adipic acid polymer, 1019,1025 Ethylene glycol, 285 Ethylene glycol, monoalkyl ethers of, 170, 444... 

Which of the following will give a polymer when condensed with adipic acid (a) ethanol (b) ethylene glycol (c) glycerol (d) aniline or (e) ethylenediamine ... 

Reaction of a dicarboxylic acid, or one of its derivatives, with a diamine leads to a linear polyamide through a condensation reaction. Commercially, nylon 6-6 (so called because each monomer has six carbons) is made from adipic acid and hexam-ethylenediamine. In this experiment, you will use the add chloride instead of adipic acid. The acid chloride is dissolved in cyclohexane, and this is added carefully to hexamethylenediamine dissolved in water. These liquids do not mix, so two layers will form. The polymer can then be drawn out continuously to form a long strand... 

---