Synthesis of poly(orgnaophosphazenes) with glycolic acid ester and lactic acid ester side groups: prototypes for new bioerodible polymers

• Published in: Macromolecules Vol. 27; no. 1; pp. 1 - 4
• Main Authors: Allcock, Harry R, Pucher, Shawn R, Scopelianos, Angelo G
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01-01-1994
• Subjects: Applied sciences; Chemical modifications; Exact sciences and technology; Inorganic and organomineral polymers; Physicochemistry of polymers; Solid state; Lactates; Hydrolysis resistance; Chemical modification; Aqueous medium; Preparation; Aqueous solution; Experimental study; Nucleophilic substitution; Lateral group; Phosphazene polymer
• ISSN: 0024-9297; 1520-5835
• DOI: 10.1021/ma00079a001

Four different poly(organophosphazenes) bearing esters of glycolic or lactic acid as side groups have been synthesized in order to investigate their stability in aqueous media. The polymers are poly[bis(ethyl glycolato)phosphazene], poly[bis(ethyl lactato)phosphazene], poly[bis(benzyl glycolato)phosphazene], and poly[bis(benzyl lactato)phosphazene]. The benzyl esters of glycolic and lactic acid were prepared by the base-catalyzed transesterification of their ethyl esters with benzyl alcohol at 90 degree C. Poly(dichlorophosphazene) was treated with a large excess of the appropriate sodium acid ester at 50 degree C to yield the fully-substituted polymer. To avoid unwanted molecular weight decline, these polymers were stored under nitrogen or in vacuum. Hydrolytic decomposition profiles in aqueous media were monitored by super(31)P NMR spectroscopy and by gel permeation chromatography (GPC). The possible utility of these polymers as biomedical materials is discussed.