Synthesis and properties of phosphorus-containing polyesters derived from 2-(6-oxido-6H-dibenz?c,e??1,2?oxaphosphorin-6-yl)-1,4- hydroxyethoxy phenylene

Abstract

A series of phosphorous‐containing aliphatic polyesters were synthesized by high‐temperature solution condensation of 2‐(6‐oxido‐6H‐dibenz〈c,e〉〈1,2〉oxaphosphorin‐6‐yl)‐1,4‐hydroxyethoxy phenylene (III) with various aromatic acid chlorides in o‐dichlorobenzene. All polyesters are amorphous and readily soluble in many organic solvents such as DMAc, NMP, DMSO, and o‐dichlorobenzene at room temperature or upon heating. These polyesters are thermally quite stable. The glass transition temperatures of these aliphatic polyesters ranged from 126.6 to 162.2°C. The degradation temperatures (Td onset) in nitrogen ranged from 424 to 448°C, and the char yields at 700°C are 20–32%. The activation energies of degradation ranged from 160.9 to 226.0 kJ/mol. The LOIs of these polyesters ranged from 36 to 43. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 3051–3061, 1998

Phosphorus-containing poly(trimethylene terephthalate) derived from 2-(6-oxido-6H-dibenz〈c,e〉〈1,2〉oxaphosphorin-6-yl)-1,4-hydroxyethoxy phenylene: Synthesis, thermal degradation, combustion and pyrolysis behavior

“…DOPO-HQ-HE was prepared according to literature methods [24]. DOPO-HQ was reacted with ethylene carbonate to yield DOPO-HQ-HE (Scheme 1).…”

“…The 1 H NMR peaks at 7.0-8.3 (a) ppm is assigned to aryl groups of DOPO-HQ-HE; the peaks occurring at 4.0 (b), 3.7 (c), 3.6 (d), and 2.9 (e) ppm belong to methylene groups of DOPO-HQ-HE; the peaks at 4.5 (g) and 4.8 (f) ppm are attributed to hydroxyl groups. The melting point of DOPO-HQ-HE obtained from DSC is 153-156 • C, which is the same as reported in the literature (157-158 • C) [24], which further indicates the successful synthesis of DOPO-HQ-HE.…”

Synthesis and reactivity of 6-mercapto-6H-dibenzo[c,e][1,2]oxaphosphinine 6-sulfide

“…The Michael-like addition of (a) with benzoquinone is a well-known reaction applied for manufacture of a commercial flame retardant. 18,19 In a previous study we demonstrated that the replacement of an oxygen atom by a sulfur atom did not prevent the analogous Michael-like addition between (b) and benzoquinone (Scheme 3). 10 Thus, the next step of our investigation consisted of reacting compound 4 with benzoquinone.…”

Preparation and phase behavior of blends of polysulfone‐based polymers with phosphorous‐containing smectic‐A liquid crystals

“…To protect the environment and human health, researchers are focused on exploiting environmental friendly halogen‐free fire retardants for plastic materials used in various industries. Phosphorus‐containing compounds have received significant attention for many years because they are considered to be the most effective flame retardants, as demonstrated in recent studies [20–25]. Phosphorus‐containing polymers tend to char rather than burn, thus, charring provides a diffusion barrier of gaseous products to the flame, shields the polymer surface from heat and oxygen, and reduces the production of combustible gas during polymer degradation [26].…”