ISSN:
0021-8995
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
Eight esters of 7-aminoheptanoic acid were prepared as monomers for nylon 7 (polyheptanamide). They were made from ε-caprolactone via the route; 6-chlorohexanoic acid, alkyl-6-chlorohexanoate, alkyl-6-cyanohexanoate, alkyl-7-aminoheptanoate. The stability of these esters against polymer formation during distillation and at room temperature increased with the number of C atoms in the alcohol. When the esters were heated at 270°C. to form the polyamide, the same trend in stability was observed; the polyamides obtained were of too low molecular weight for melt spinning. Upon heating ethyl-7-aminoheptanoate with water (mole ratio 1 to 〉 3) at 100°C., a mixture of 7-aminoheptanoic acid with mainly dimeric acid and ester was obtained. This product (“precursor”) was a stable solid at room temperature which could readily be converted at atmospheric pressure within 2 hr. to high molecular weight, spinning grade nylon 7. The melting point, density, moisture regain, and sticking temperature of nylon 7 were compared with those of nylons 6, 8, 9, 10 and 11. Nylon 7 was melt spun into high tenacity yarn and its textile properties were discussed in comparison with those of nylons 6 and 66. The low oligomer content of nylon 7 (1.5%) made extraction of the resin before spinning unnecessary.
Additional Material:
1 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/app.1963.070070308
Permalink
