Synthesis and Properties of some Phosphorus-containing Polyesters

Phosphorus-containing polyesters were prepared by polycondensation of 2-(6-oxido-6H-dibenz >c,e< >1,2< oxaphosphorin-6-yl)-1,4-benzenediol with different aromatic dicarboxylic acids using a SOCl2/pyridine condensing agent. The polymers were soluble in polar organic solvents such as N-methylpyrrolidone, N, N-dimethylformamide, tetrahydrofuran and chloroform. They showed high thermal stability having a decomposition temperature above 360°C and char yield at 700°C in the range of 19-32%. The glass transition temperature was in the range of 180-194°C. Solutions of the polymers in N, N-dimethylformamide showed fluorescence having maximum emission wavelength around 362 nm. One of the polymers exhibited thermotropic liquid crystalline behavior

Preparation and cytocompatibility evaluation for hydrosoluble phosphorous acid-derivatized cellulose as tissue engineering scaffold material

Chemical modification of cellulose by phosphorylation enhances its bioactivity and provides new derivatives and materials with specific end uses. In the present study, cellulose derivatized with phosphorous acid was obtained using the reaction of microcrystalline cellulose with phosphorous acid-urea mixture, in molten state, in comparison with others methods that used different solvents and catalysts. Completely water soluble films with a substitution degree close to one were obtained and characterized by analytical and spectral analysis (FT-IR, (31)P NMR), contact angle, metallographic microscopy and atomic force microscopy (AFM). 31P NMR spectra of derivatized cellulose showed a signal at 2.58 ppm (assigned to P-O-C6) while the doublets at 4.99-5.29 and at 7.38 ppm were assigned to P-O-C2 and P-O-C3, respectively; thus, the formation of monosubstituted phosphorous acid esters of cellulose is advocated. Contact angle measurements showed that the work of adhesion is more important in water than in ethylene glycol, for the phosphorous acid derivatized cellulose. The cytocompatibility of this hydrosoluble derivatized cellulose was tested by direct contact and also by indirect assays on normal human dermal fibroblasts and on osteoblast-like cells (human osteosarcoma). Cell growth on phosphorylated cellulose pellicle and the results from viability assays had shown a good cytocompatibility and lack of toxicity. Phosphorous acid derivatized cellulose would offer a promising biomaterial, useful as scaffolds for new biopolymer composites, and subject for further development as an ionic crosslinker.

Synthesis and Characterization of Some Polyesters and Poly(ester-imide)s Based on Bisphenol-A Derivatives

Aromatic polyesters and poly(ester-imide)s based on bisphenol-A derivatives were prepared by solution polycondensation at high temperature of three diols with an aromatic diacide chloride containing two preformed ester groups, namely terephthaloyl-bis-(4-oxybenzoylchloride) or two diacide chlorides containing preformed imide rings, namely 4-chloroformyl- N ( p-chloroformylphenyl)-phthalimide and 2,2-bis[ N-(4-chloroformylphenyl)phthalimidyl] hexafluoropropane. The polymers were easily soluble in polar organic solvents, such as N-methylpyrrolidone, N , N -dimethylformamide, N , N -dimethylacetamide and chloroform. They showed high thermal stability, the decomposition temperature being above 320 °C and the glass transition temperature in the range 92—196 ° C. Some of the polymers exhibited thermotropic liquid crystalline behavior.

New Polyesterimides Containing Bulky, Cyclic Phosphorus Groups

A new phosphorus-containing monomer, bis( N-hydroxyethyl-phthalimidyl)-bis(9,10-dihydro-9-oxa-10-oxide-10-phosphaphenanthrene-10-yl)methane, that contains preformed imide rings and flexible linking groups was synthesized. This compound was used to synthesize new phosphorus-containing polyesterimides by solution polycondensation with various aromatic diacide chlorides such as terephthaloyl chloride, terephthaloyl-bis-(4-oxybenzoylchloride), 4-chloroformyl- N( p-chloroformylphenyl)-phthalimide and 2,2-bis(4-chloroformyl- N-phthalimidyl)-diphenylmethane. The rates of the polycondensation reactions were calculated from kinetic investigations. The polymers were readily soluble in polar organic solvents, such as N-methylpyrrolidone, N, N-dimethylacetamide and N, N-dimethylformamide. The polymers were analytically, spectrally and thermally characterized.