Synthesis, characterization, and thermal properties of phosphorus‐containing, wholly aromatic thermotropic copolyesters

Abstract

A series of phosphorus-containing, wholly aromatic thermotropic copolyesters from acetylated 2-(6-oxide-6H-dibenz͗c,e͗͘1,2͘oxa phosphorin-6-yl)-1,4-dihydroxy phenylene, p-acetoxybenzoic acid, terephthalic acid, and isophthalic acid were prepared by melting polycondensation. The structure and basic properties of the polymers, such as the glass-transition temperature (T g ), melting temperature (T m ), thermal stability, crystallinity, and liquid crystallinity, were investigated with Fourier transform infrared, elemental analysis, differential scanning calorimetry (DSC), thermogravimetric analysis, wide-angle X-ray diffraction, and hot-stage polarizing optical microscopy. The copolyesters had relatively high T g values ranging from 183 to 192°C. The T m values obtained from DSC curves for samples P-20 and P-25 were 290 and 287°C, respectively (where the number in the sample name indicates the molar fraction of the phosphorus-containing monomer in the reactants). The initial flow temperatures of other samples observed with hot-stage polarizing microscopy were 271-290°C. The 5% degradation temperatures in nitrogen ranged from 431 to 462°C, and the char yields at 640°C were 41-52%. All the copolyesters, except P-40, were thermotropic and nematic.

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

“…1,3-Propanediol (PDO) (fiber grade), tetrabutyl titanate [Ti(OC 4 H 9 ) 4 , AR grade] and zinc acetate [Zn(CH 3 COO) 2 , AR grade] were purchased from Kelong Chemical Reagent Factory (Chengdu, China). 2-(6-Oxido-6H-dibenz c,e 1,2 oxaphosphorin-6-yl)-1,4-hydroquinone (DOPO-HQ) was prepared according our previous publication [23]. Ethylene carbonate was purchased from Aladdin Reagent Company.…”

Pyrolysis study of a phosphorus-containing aliphatic–aromatic polyester and its nanocomposites with layered silicates

“…This fact can be attributed to the formation of polyarylates that are known to be good charring polymers [26], with the char yield of 41-52% at 640 C under nitrogen. Introducing nanocomposites decreases the amount of non-volatile products of P-PES without changing the chemistry of main pyrolysis reactions.…”

Preparation and characterisation of a novel fire retardant PET/α-zirconium phosphate nanocomposite

“…War et al [5][6][7][8] have also synthesized some novel phosphorus-containing fire retardants in polyester copolymers. Recently our laboratory in Chengdu has successfully synthesized a series of phosphorus-containing fire retardant polyesters copolymers including those with phosphorus linked as pendent groups and incorporated into the main chain [9][10][11][12][13][14][15][16].…”