Synthesis and characterization of PEDMCD as a flame retardant and its application in epoxy resins

In this study, a highly effective flame retardant agent, called polybicyclopentaerythritol phosphate-O-4-imino-p-phenylmethane-4-imino-2-chloro-1,3,5-s-triazine (PEDMCD), has been prepared through a direct polycondensation reaction.

High-Performance Liquid Crystalline Polyesters: Influence of the Synthetic Pathway on the Thermal Properties

Liquid crystalline (LC) copolyesters derived from 4-hydroxybenzoic acid, terephthalic acid, and bisphenol A were synthesized under a variety of reaction conditions. Carboxylic groups in the raw materials were involved in either direct polycondensation or transesterification reactions. Protecting the carboxylic groups via methyl ester or phenyl ester formation was found to increase the yield and the molecular weight of the samples. It turned out that the maximal value of the degree of polymerization and, consequently, the highest heat resistance was observed for the samples prepared using phenyl esters of carboxylic acids.

Novel soluble and heat-resistant polyamides derived from 4-(4-diphenylphosphino) phenyl-2,6-bis(4-aminophenyl)pyridine and various aromatic dicarboxylic acids

New diamine, 4-(4-diphenylphosphino)phenyl-2,6-bis(4-aminophenyl)pyridine, was prepared, and the related polyamides (PAs) bearing 2,6-diphenylpyridyl units and pendant diphenylphosphinophenyl groups were synthesized by direct polycondensation of this diamine and various aromatic diacids in N-methyl-2-pyrrolidinone (NMP) using triphenyl phosphite and pyridine as condensing agents. The resulting PAs with inherent viscosities of 0.78–1.06 dL g−1 are readily soluble in polar aprotic solvents such as NMP, N, N-dimethylacetamide, and dimethylsulfoxide as well as less polar solvents such as m-cresol and pyridine. All the PAs are amorphous and could be solution-cast into transparent, flexible, and tough films, which have tensile strengths of 68.2–88.8 MPa, tensile moduli of 1.9–2.4 GPa, and elongations at break of 5.4–10.3%. These polymer films also exhibit high optical transparence with the UV cutoff wavelength in the 361–412 nm range. These PAs display glass transition temperatures of 316–332°C, 10% mass loss temperatures of 524–553°C, and more than 48% residues at 800°C in nitrogen, respectively. Their high char yields and good limited oxygen index values ranging from 39 to 44 indicate the prepared PAs show good thermal stability and flame-retardant property.

Synthesis and characterization of SPDSCD and its flame retardant application on epoxy resins

In this study, a flame retardant agent, 2,4,8,10-tetraoxo-3,9-diphosphospiro[5.5]undecane spirophosphate-4,4-diaminopair benzene disulfone-1,3,5-himetriazine (SPDSCD), is synthesized through a direct polycondensation reaction.

In situ synthesis of poly(ether ester) via direct polycondensation of terephthalic acid and 1,3-propanediol with sulfonic acids as catalysts

Sulfonic acid-comprising catalysts were explored to in situ fabricate ether segments in the process of esterification of terephthalic acid and 1,3-propanediol, and developing a new pathway of poly(ether ester)s synthesis without the addition of oligoether as starting materials.

High Molecular Weight Poly(lactic acid) Synthesized with Apposite Catalytic Combination and Longer time

Biodegradable polymeric materials derived from renewable resources have attracted tremendous attention in different application. Polylactic acid (PLA) is one of the most useful biodegradable polymers. It is difficult to synthesize high molecular weight polylactic acid by direct polycondensation. The present work describes the synthesis of high molecular weight PLA by varying the duration of reaction and changing the sequence of catalyst addition. Binary catalyst used was SnCl2.2H2O/maleic anhydride and p-toluene sulfonic acid. PLA with molecular weight (6.503X105) was obtained in 50 hours. FTIR, H1 and 13C NMR ascertained the structure of synthesized PLA whereas GPC was used for determining molecular weight.