Standard

NS-EN ISO 960:1997

Tilbaketrukket
Forhåndsvisning

Rettelser og tillegg kjøpes separat.

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Omfang

1.1 This International Standard specifies methods for the determination of the water content of polyamides and copolyamides as granules and finished articles. The methods are applicable for determination of water content down to 0,01 % (m/m). The water content is of importance in connection with the processing of PA, during which it should have a low value to prevent degradiation, and for checking the moisture content of test specimens and finished articles. 1.2 Four alternative methods are specified in this International Standard. Method A is an extraction method using anhydrous methanol and titration of the water by the Karl Fischer method. It is applicable to granules having a maximum size of 4 mm x 4 mm x 3 mm and can be used for all polyamides and copolyamides. Method B is a method of extraction by melting under vacuum and titration of the water by the Karl Fischer method. It may be applied to granules or pieces of mouldings but not to fine powders (particle size less than 400 um). For low water content (less than 0,01 % (m/m) and precise determination, it is necessary to make a correction for the water of polycondensation 1). This method is not recommended when, during the determination, due to a change in molecular mass, additional water is formed or existing water is bound, except when appropriate correction can be made. Method C is a method for extraction by dissolving in a mixture of 3-methylphenol and toluene and titration of the water by the Karl Fischer method. It yields results close to those obtained by method A. It has the advantage of being applicable to granules and powders of all sizes and to finished articles with little or no reduction in size. NOTE - The three methods A, B and C differ in the procedure for isolating the water, which is determined in all three cases by the Karl Fischer method. Method D is a manometric method. The water content is determined from the pressure increase after evaporation of the water under vacuum. This method cannot be used for polyamides polymerized with strong acids. 1.3 Method C is the reference method. 1) See KLINE, G.M., Analytical Chemistry of Polymers. Intersc. Pub., Part 1, p. 282 (1958).

Dokumentinformasjon

  • Standard fra SN
  • Publisert:
  • Tilbaketrukket:
  • Utgave: 1
  • Versjon: 1
  • Varetype: NAT
  • ICS 83.080.20
  • National Committee CEN/TC 249/SC 1/WG 10

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