Synthesis of Poly[(amino acid alkyl ester)phosphazenes]

Abstract

for kp as high as 120 L/(mol s) at 0 °C. Considering the assumptions made, this value should be taken as a lower limit.In conclusion, the anionic polymerization of e-caprolactone in tetrahydrofuran represents a living ring-chain equilibrium system. The product distribution is essentially determined by the entropy term, the lower cyclics being favored over the linear polymers at higher dilution, as expected from the Jacobson-Stockmayer theory. The very fast equilibration, as shown in this paper, should be considered in studies concerned with either or both the thermodynamics of the ring-opening polymerization and the statistics of chain conformations of the species involved.

Miscibility and in vitro osteocompatibility of biodegradable blends of poly[(ethyl alanato) (p-phenyl phenoxy) phosphazene] and poly(lactic acid-glycolic acid)

“…The synthetic flexibility of polyphosphazenes has led to the development of a wide variety of polymers with diverse physical, chemical and biological properties [10]. Among them, amino acid ester polyphosphazenes are known to be hydrolytically sensitive and degrade into non-toxic and neutral products [11][12][13][14]. Also the degradation rates can be modified by varying the nature and ratio of the side groups [11][12][13][14].…”

“…Among them, amino acid ester polyphosphazenes are known to be hydrolytically sensitive and degrade into non-toxic and neutral products [11][12][13][14]. Also the degradation rates can be modified by varying the nature and ratio of the side groups [11][12][13][14]. Thus, amino acid ester polyphosphazenes have been found to be attractive candidates for biomedical applications [15][16][17].…”

“…It was shown that the acidic degradation products of PLAGA could be effectively neutralized by the degradation products of polyphosphazenes [21]. However, the mechanical performance of EG-PPHOS due to the lower glass transition temperature (T g ) value makes this polymer system less optimal for bone tissue engineering applications [11,14,20]. On the other hand, poly[(50% ethyl alanato) (50% p-phenyl phenoxy) phosphazene has a higher T g value due to the presence of the bulky aromatic side groups.…”

Polyphosphazenes with etheric side groups: prospective biomedical and solid electrolyte polymers

“…This is a consequence of the substitutive mode of synthesis used for these polymers, as described in a number of earlier publications. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] The method involves the prior synthesis of a reactive, high polymeric poly(dihalophosphazene) intermediate, such as 1, by a ring-opening polymerization of the corresponding cyclic trimer, followed by replacement of the halogen atoms by one or more of a wide variety of organic or organometallic nucleophiles.…”

Biocompatibility and Long-Term Toxicity of InnoPol Implant, a Biodegradable Polymer Scaffold

“…Biodegradable polymers are of interest in medicine because these polymers produce non-toxic degradation products which ultimately circumvent surgical removal of the drug-depleted devices [1,4]. So both the use of biomaterials and the number of different applications for biomaterials are increasing.…”