Novel micro-crosslinked poly(organophosphazenes) with improved mechanical properties and controllable degradation rate as potential biodegradable matrix.
As biodegradable materials, linear polyphosphazenes undergo rapid hydrolysis degradation but exhibit poor mechanical properties. Blending with biodegradable polyesters or inorganic particles strengthen their mechanical properties but give rise to slower degradation rate. To balance the mechanical properties and the degradation rate, micro-crosslinked polyphosphazenes were synthesized in this study. Their glass transition temperatures, mechanical properties, and in vitro degradation behavior were investigated. 2-hydroxyethyl methacrylate (HEMA) was firstly attached to the side chain along with glycine ethyl ester to prepare co-substituted poly(organophosphazene) with pendant ethenyl substituents. The co-substituted poly(organophosphazene) was blended with HEMA or acrylic acid (AA) followed by a free radical polymerization to prepare micro-crosslinked poly(organophosphazenes). The resulting crosslinked polymers showed two separate glass transition temperatures depending on the HEMA or AA feed. Incorporation of crosslinking affected the mechanical properties positively. Crosslinked poly(organophosphazenes) showed an approximately 11-17 fold increase in terms of modulus of elasticity when compared to the linear counterpart. In vitro degradation tests indicated that HEMA-crosslinked polymers hydrolyzed at a retarded rate while AA-crosslinked polymers hydrolyzed at a moderate rate compared to linear polymers.
School of Chemistry and Chemical Technology, Shanghai Jiao Tong University, Shanghai 200240, China.
Yanjun
Y
Cui
Xian
X
Zhao
Xiaozhen
X
Tang
Yinpei
Y
Luo
D001672:Biocompatible Materials / Q000737:chemistry*; D002845:Chromatography; D003432:Cross-Linking Reagents / Q000494:pharmacology*; D005609:Free Radicals; D005898:Glass; D005998:Glycine / Q000031:analogs & derivatives*; D006868:Hydrolysis; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D008956:Models, Chemical; D009943:Organophosphorus Compounds / Q000494:pharmacology*; D011091:Polyesters / Q000737:chemistry; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D013696:Temperature; D013997:Time Factors
D001672:Biocompatible Materials; D003432:Cross-Linking Reagents; D005609:Free Radicals; D008689:Methacrylates; D009943:Organophosphorus Compounds; D011091:Polyesters; D011108:Polymers; C108974:poly(phosphazene); C022010:glycine ethyl ester; C005044:hydroxyethyl methacrylate; D005998:Glycine