Phosphorus-containing stabilizers

Esters of Phosphoric Acid and Other Phosphorus-Containing Stabilizers... 

We should mention that the overwhelming majority of phosphorus-containing stabilizers are produced on the basis of readily available starting materials m a high yield, and their synthesis is simply accomplished under the conditions of industrial production. 

Of the phosphorus-containing stabilizers, aromatic esters of phosphoric acid, such as tricresyl phosphate, have received the most widespread use. In many of them, stabilizing action is combined with plasticizing action. The properties of a number of esters of phosphoric acid used as stabilizers and plasticizers of polyvinyl chloride are discussed in the collection [287]. 

Phosphorus-containing stabilizers are used in practice in a mixture with other stabilizers - hydrogen chloride acceptors, phenols, organotin compounds, or epoxide compounds. 

Phosphorus containing poly(maleimide-amines) were synthesized from N,N -bisdichloromaleimido-3,3 -diphenyl alkylphosphine oxides and aromatic diamines or piperazine [144]. The polymers prepared from piperazine are soluble in DMF, DM AC, DMSO, etc., but have poor thermal stability and flame retardancy. 

It has been observed that all the phenoxaphosphine ring-containing polymers have excellent thermal stability and show better heat resistance than open-chain phosphorus containing polymers. The phenoxaphosphine polymers containing aromatic rings in the backbone show little degradation below 400°C in air. 

Some phosphorus-containing surfactants have bacteriostatic properties. In combination with their physiological acceptance they are used in cosmetics and pharmaceuticals. In mutanase oral anticarie compositions the combination of alkyl phosphates and nonionic surfactants stabilizes mutanase. A dentifrice useful for prevention of dental caries contains 0.5% sodium lauryl phosphate and 1.5% polyoxyethylene (20) sorbitan monooleate [222]. 

M. Fournier, C. Fuemi-Jantou, C. Rabia, G. Herve, and S. Launay, Polyoxometalates Catalyst Materials X-Ray Thermal Stability Study of Phosphorus-containing Heteropolyacids Hj xPMi2. xVx04o13-14H20 (M = Mo, W x = 0-1), J. Mater. Chem., 2, 971-978 (1992). 

The stabilizer may consist of carboxylic acids and phosphorus-containing organic acid salts such as hexametaphosphates, polyphosphates and phosphonates. The mechanism of action of the stabilizer admixture is thought to be related to the inhibition of CSH and CH nucleation. It is claimed that the nucleation process is controlled more comprehensively than that obtained with conventional retarders [10], Cement hydration is arrested by the admixture acting on all phases of cement hydration including the C3A fraction. The claim is... 

The compounds of phosphorus containing the quinquevalent element are generally the most stable but with antimony and bismuth those of the tervalent element are the most stable, in fact few compounds of quinquevalent bismuth are known. The difference in stability of the ter- and quinque-valent compounds of arsenic is not so marked. Evidence of arsenic existing as a quadrivalent element in certain organic compounds has been observed.1... 

For polyester, the reported work82 done in Sichuan University of China, involves adding MMT clay in a copolymer of poly(ethyleneterephthalate), which with a phosphorus-containing monomer could produce PET with higher thermal stability and char-forming tendency. However, fibers were not produced from this PET-nanocomposite polymers. 

With regard to reactive flame-retardants, two routes can be followed to improve thermal stability and fire behavior of PU foams use of brominated or phosphorus-containing polyol or, for rigid foams, the introduction inside polymer backbone of more thermally stable structure than urethane, mainly isocyanurate, but also uretidione rings or carbodiimide.19... 

The large group of inhibitors of free radical chain reactions are frequently used in combination with metal salts or organometallic stabilizers. They are amines, sulfur- or phosphorus-containing compounds, phenols, alcohols, or chelates. Aromatic phosphites at about 1 p.p.r. chelate have undesirable metal impurities and inhibit oxidative free radical reactions. Some of the more popular are pentaerythritol, sorbitol, melamine, dicyan-diamide, and benzoguanamine. Their synergistic effect is utilized in vinyl floors where low cost is imperative. 

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