Phosphorus-containing polyurethane-semicarbazides

The flammability of polymer materials can be reduced by the chemical incorporation of phosphorus atoms in their macromolecules, using either phosphoric acid dihydrazides as chain extenders, or phosphorus-containing oligoethers IX-XII in the prepolymer synthesis [5]. 

The phosphorus-containing polyurethane-semicarbazides VIII are obtained in two steps (i) preparation of the phosphorus-containing prepolymer VII and (ii) chain extension by isophthalic or 0-substituted phenylthiophosphoric acid dihydr azide  

R =(CH2CH20)2-P-(CH2CH2)2 (CH2CH20)2-P-(CH2CH2)2/CH2CH20)r-P-(CH2CH2)2 CHs X CbH5 

The study of the ignition time, the time of self-extinction, and the weight losses at burning has shown that the synthesized phosphorus-containing poly-urethane-semicarbazides are among the conventional fire-proof or self-extinguishing materials. 

The possibility of using the polyurethane ionomeric resins as water dispersions, free of organic solvents and surface-active agents, simplifies the development of environmentally friendly production facilities [6-8]. Hydrazine-containing polyurethanes having ionic groups in their macrochains combine the properties of ionomeric resins with those of polyurethanes based on hydrazine derivatives [6,9]. 

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Polyurethane-semicarbazides (in earlier reports, they are also called poly-urethane-acylsemicarbazides) are linear polymers containing urethane and (acyl)semicarbazide groups in their macromolecules. Sulfur or phosphorus can also be included in the macrochains [2]. 

Goncharova L B, Grekov A P, Batjaeva S I and IVoev K D (1986) Phosphorus-containing cation-active polyurethane semicarbazides, UkrKhim Zh 52 1100-1104 (in Russian). 

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