Kurrol’s salts

Kuhni contacters, 10 778 Kujimycins, 15 280 Kunster marrow needle, 3 743 Kurnakov test, 19 656 Kurrol s salts, 13 848 Kuruma shrimp, common and scientific names, 3 188t K X rays, 21 311 KX zeolite. See Zeolite KX Kyanite, 2 345t in clays, 6 685 in coal, 6 718 Kynarflex, 7 641 Kynar SL, 7 641 Kynol fibers, 13 797 Kyoto Protocol, 11 721 KY zeolite. See Zeolite KY... 

A range of high-molecular alkali polyphosphates occur in several crystalline forms. In the case of the sodium and potassium compounds the trivial names Maddrell s and Kurrol s salts have been adopted and these... 

Fio. 9. Various chain types in crystalline high-molecular phosphates (a) (LiPCh) low temperature form (b) Rb(P03)x (c) (NaPCb) Maddrell s salt (high temperature form) (d) (NaP().i)x Kurrol s salt. 

In the system (KII2P04—H3P04) high-molecular potassium polyphosphates are formed on heating, together with acid mono- and di-phosphate but only a little oligophosphate (363). But tertiary P04 tetrahedra occur not only in phosphates with Na P < 1. They can also be detected in Graham s and Kurrol s salt with Mr P = 1 (224, 284, 85, 86) and are also formed in melts of anhydrous trimetaphosphates, especially in a dry atmosphere (364). Their equilibrium concentration in the melt is about 2%. 

Potassium Metaphosphate Potassium Polyphosphates Potassium Kurrol s Salt... 

Addition of active nuclei to a monomer solution or melt can shorten the induction period, enable quicker crystallization and avoid amorphous products. These nuclei may be of the same polymer as in polyformaldehyde or Kurrol s salt nucleation or they may be different. The effect of nucleation by monomer crystals was shown in the -aminocaproic acid pol5unerization (18) where an overwhelming amount of the gaseous monomer pol5mierized on the monomer crystals rather than on the enormously larger wall area. 

Kurroll s salt. NaP03(IV). A high-tempera-ture crystalline form of sodium metaphosphate. 

Alkali metal and alkaline earth polyphosphates crystallize as short chains, two to six phosphate groups per chain or very long chains with hundreds to thousands of PO3 per chain. All polyphosphates in the alkali metal and alkaline earth systems are amorphous in the intermediate chain lengths. Control of the short chain length polyphosphates, both crystalline or amorphous, is a function of R, the M2O-P2O5 ratio. The control of the chain lengths of very long crystalline polyphosphates as Maddrell s salt, Kurrol s salt, and calcium phosphate fibers is not well understood. 

Determine whether or not cross-1 inked potassium Kurrol s salt contains cross-links in the crystalline phase and is indeed a crystalline ultraphosphate or does the salt obey the phase diagram for the two component K2O-P2O5 system. 

X-ray powder patterns were very carefully determined of the compositions 1.02, 1.00, 0.94, 0.75, and 0.65. The x-ray patterns were identical for ratios 1.02 through 0.94 except for minor variations in intensities that were probably a result of orientation of the very fibrous crystals. An amorphous phase was found mixed with normal Kurrol s salt pattern in the 0.75 and 0.65 samples while a sample with a K2O-P2O5 ratio of 0.50 could not be crystallized. 

The following experiment was performed to determine if it is possible to mimic the properties obtained when potassium Kurrol s salt with a 0.98 K2O-P2O5 ratio is prepared from a melt in a furnace. The approach is to mix the potassium ultraphosphate with a ratio of 0.65 with potassium Kurrol s salt made with a ratio K2O-P2O5 = 1.0. 

Attempts were made to grow short chain length Kurrol s salt from melts with M2O-P2O5 ratios between 1.04 (n = 50)... 

Cross-linked potassium Kurrol s is prepared in exactly the same manner as the calcium polyphosphate fibers. The only difference is potassium is substituted for calcium in the preparation of potassium Kurrol s salt. There is strong reason to question whether or not the strange solution behavior of cross-linked potassium Kurrol s salt is a result of cross-linking in the crystalline phase or is a result of ultra long polyphosphate chains mixed with an independent ultraphosphate phase that contains the required cross-linking. All of the observations which led to the belief that the molecule-ions in the crystalline phase were cross-linked can be explained based upon the two phase model where the ultraphosphate phase is rather quickly degraded in aqueous solutions to form acidic groups. 

In the discussion to follow, the great differences between sodium and potassium condensed phosphate phase systems is highlighted. Where the sodium Kurrol s salt is metastable with respect to the cyclic sodium trimetaphosphate there is no cyclic metaphosphate in the potassium phosphate two component phase system and the Kurrol s salt is the only stable compound in the phase system with K2O-P2O5 ratios near unity. 

It has been claimed that long chain ammonium polyphosphates can be treated with potassium hydroxide to form long chain polyphosphates that crystallize from solution as the dihydrate. It was suggested that the phosphate was a Kurrol s salt, but only after the salt... 

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