AH-salt

Demineralizers are often used to treat raw makeup water or condensate where high purity is required, such as in large central station boHers that operate at high steam pressures. Demineralizers employ a combination of cation and anion exchange to remove additional material, including sodium and ammonium cations. VirtuaHy aH salt anions, such as bicarbonate, sulfate, and chloride, are removed and replaced by hydroxide ions in the demineralizer. 

Preparation of Polyamide-6,6 from Hexamethylenediammonium Adipate (AH Salt) by Condensation in the Melt... 

The adipic acid solution is now placed in a 250-ml beaker and the diamine solution added dropwise with stirring over a period of 8 min, during which the solution warms up to 40-45 °C. After stirring for a further 30 min and allowing to cool, the crystallized AH salt is filtered off with suction, washed twice with 95% ethanol and dried in vacuum. Yield 90-95% mp 183 °C (with loss of water) pH value of 9.5% aqueous solution 7.62. Impure AH salt can be recrystallized from ethanol/water mixtures (volume ratio 3 1). 

A 50 ml pear-shaped flask, fitted with distillation head, air condenser, vacuum adapter, and receiver is three-quarters filled with AH salt and the air removed by evacuation and filling with nitrogen. It is then heated under nitrogen for 1 h on a silicone oil bath at 220 °C, and for further 3 h at 260-270 °C. After cooling, the flask is broken carefully with a hammer.The polyamide from adipic acid and hexamethylenediamine melts at 265 °C. It can be spun from the melt into threads which can be cold drawn.The viscosity number is determined in concentrated sulfuric acid or in 2 M KCI in 90% formic acid (see 5ect.2.3.3.3.1). 

AH Salt. [BASF AG] Hexamethylene-diamine adipate monomer for p of nylon 6/6. 

Diamine H extra. [BASF AG] 1,6-Hexanediamine intermediate for prod. of AH salt... 

AH Salt [BASF AG] Hexameth ene-diamine adipate mcmtnnerfariHOd. of nykm 6/6. 

AH Salt. See Hexamethylenediamine adipate AIBN. See 2,2 -Azobisisobutyronitrile Airbond ACP40, Airbond ACP65. See Ethylene/VA copolymer Airbond ACP67. See Acrylic resin Airbond ACP74. See Vinyl acetate/ethylene/vinyl chloride terpolymer Airbond SP102. See Acrylic resin Airedale blue D. See Direct blue 15 Airflex 100 HS Airflex 105 Airflex 108 Airflex 109 Airflex 110 Airflex 12Q, Airflex 124 Airflex 125 Airflex 129 Airflex 140 Airflex 141 Airflex 144. See EthyleneA/A copolymer Airflex 154. See Vinyl acetate/ethylene/vinyl chloride terpolymer... 

Hazardous Decomp. Prods. Heated to decomp., emits toxic vapors of NOx Uses Monomer for prod, of nylon 6/6 Trade Name Synonyms AH Salt t[BASF AG http //WWW. basf. de]... 

The necessary functional group equivalence required for the poly condensation is achieved by first producing the salt from molar equivalents of the diamine and dicarboxylic acid. For example, adipic acid and hexamethylene diamine form what is known as the AH salt. The purified salt is directly used in the melt polycondensation. The amidation equilibrium is so favorable that the polycondensation can take place in the presence of water, which is therefore used as a heat sink. A typical industrial synthesis is, for example, the polycondensation of the AH salt a 60%-80% sludge of the salt is precondensed with a little acetic acid as regulator (see also Section 28.2.3.2) at 275-280° C for 1-2 hr at 13-17 bar, that is, at the vapor pressure of the steam produced. After a yield of 80%-90% has been reached, further condensation takes place above the melting temperature of 264° C under vacuum. 

Caprolactam for use as fibers is hydrolytically polymerized in batches as 80%-90% aqueous solutions with 0.2%-0.5% acetic acid and ethylene diamine at 250-280° C. The acetic acid acts as chain stabilizer (see above). The ethylene diamine increases the amine equivalent of PA 6 so that mixed weaves of Perlon and wool can be evenly dyed. The water is removed as steam in the polymerization progresses. Caprolactam is also polymerized continuously by what is known as the VK process (vereinfacht-A ontinuierliche, or simplified continuous, process). This process is carried out without pressure with, for example, 6-amino caproic acid or AH salt as initiator. In contrast to the production of nylon 6,6, this process can proceed continuously the melt can be directly spun from the reactor. Polyamide 6 fibers have good properties but they yellow slowly since pyrrole structures are formed at the chain ends. 

The main raw material for the production of polyamide 66 is an aqueous solution of the organic salt obtained by the reaction of 1.6 hexamethylenediamine and 1.6 hexanedicarboxylic acid (adipic acid), also called AH salt, 66 salt or nylon salt. 

AH salt organic salt obtained by the reaction of 1.6 hexamethylenediamine and 1.6 hexanedicarboxylic acid... 

Statistically configured polyester amides are always compostable if they have at least 30 wt.% ester content, regardless of whether their amide contents were introduced to the synthesis via e-caprolactam or AH-salt (adipic acid/hexamethylene diamine) [953]. 

The mechanical properties in AH-salt polyester amides differ considerably from those of e-caprolactam polyester amides. AH-salt polyester amides are stiff, hard, and crystalline. They are suitable for injection molding applications. Polyester amide in common environments behaves like polyethylene it is suitable for many applications and even waterproof. 

Information about SSP of aliphatic polyamides was for the first time disclosed in a patent of DuPont [27] concerning Nylon-6,6. In this patent, polycondensation of hexamethylene diammonium adipate (AH-salt) was initially conducted in the... 

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