Synthesis and characterization of biodegradable network poly(ethylene glycol) films with elastic properties

Abstract

Novel biodegradable network films with elastic properties were prepared from trimesic acid (Y) and poly(ethylene glycol)s (PEGs) with different molecular weights (MW) and/or 4,7,10-trioxa-1,13-tridecanediamine (I). Prepolymers prepared by a melt polycondensation were cast from N,N 0 -dimethylformamide solution and postpolymerized at 2908C for various times to form a network. The resultant films were transparent, flexible, and insoluble in organic solvents. The X-ray diffraction scattering pattern showed that all network films are amorphous. The densities of the network films decreased, whereas their water uptake increased with increasing MWs of PEG. The thermal and tensile properties were measured in dry and wet conditions and were affected remarkably not only by MWs of PEG, but also by the water uptake of the films. The glass transition temperatures (T g ) decreased with increasing MWs of PEG. YPEG 200 and YPEG 1000 films showed good elastomeric properties with an ultimate elongation of 225 and 277%, respectively, in dry condition. The tensile strength of 13 MPa and Young's modulus of 214 MPa were the highest for YPEG 200 among the network elastic films studied. All sample films in wet condition had lower T g 's and tensile properties. The hydrolytic degradation was measured by the weight loss of network films in a buffer solution with or without Rhizopus delemar lipase at 378C. The degree and the rate of the degradation increased with increasing MWs of PEG, which is compatible with the increase in water uptake of the films. Incorporation of large amount of I moiety into YPEG 1000 film increased the glass transition temperatures, tensile strength and Young's modulus, but depressed elastic nature of the films.

Hydration-Induced Phase Separation in Amphiphilic Polymer Matrices and its Influence on Voclosporin Release

“…Water is known to exist in different states (bound and free water) and may form clusters depending on the ratio of hydrophobic and hydrophilic domains in polymers [ 4 ]. The structure [ 5 , 6 ] and the hydration [ 7 , 8 , 9 ] of PEG-containing copolymers, and the clustering of water in polymers [ 4 , 10 , 11 , 12 , 13 ] are expected to affect both drug release and polymer resorption. For example, water is shown to disrupt the crystalline nature of PEG incorporated into hydrophobic chains of either poly(tetramethylene oxide) and poly(dimethyl siloxane) [ 14 ].…”

Effects of Nanofillers on the Hydrolytic Degradation of Polyesters

“…Compared with PLA, PGA, and PLGA, the degradation rate of PCL is much slower and often used to build devices for controlled drug release, long-term tissue scaffolds and implants. 18 The mechanical and thermodynamic properties along with the degradation behaviors of the common types of polyesters are shown in Table 1.…”

Preparation and properties of biodegradable network poly(ester-carbonate) elastomers

“…We have previously reported the novel biodegradable elastomers with a regular network structure from aliphatic or aromatic multifunctional carboxylic acids and the macrodiols such as poly(3-caprolactone) diols [8,9] and poly(ethylene glycol)s [10], which showed the interesting mechanical and degradation properties depending on the structures of macrodiols. Our recent interests have continued on the investigation of this type of elastomers, that is, the regular network elastomeric polymers from the biodegradable macrodiols.…”