Lactic acid based PEU/HA and PEU/BCP composites: Dynamic mechanical characterization of hydrolysis.
Lactic acid based poly(ester-urethane) (PEU-BDI) and its composites with 20 and 40 vol.% bioceramic filler were characterized prior to their use as biocompatible and bioabsorbable artificial bone materials. Morphological, dynamic mechanical properties, and degradation of these either hydroxyapatite or biphasic calcium phosphate containing composites were determined. Addition of particulate bioactive filler increased the composite stiffness and the glass transition temperature, indicating strong interactions between the filler and matrix. Materials were sterilized by gamma-irradiation, which reduced the average molecular weights by 30-40%. However, dynamic mechanical properties were not significantly affected by irradiation. Specimens were immersed in 0.85 w/v saline at 37 degrees C for 5 weeks, and changes in molecular weights, mass, water absorption, and dynamic mechanical properties were recorded. All the composite materials showed promising dynamic mechanical performance over the 5 weeks of hydrolysis. Average molecular weights of PEU-BDI and its composites did not change substantially during the test period. PEU-BDI retained its modulus values relatively well, and although the moduli of the composite materials were much higher, especially at high filler content, they exhibited faster loss of mechanical integrity.
Department of Chemical Technology, Polymer Technology, Helsinki University of Technology, P.O. Box 6100, 02015 HUT Espoo, Finland.
Jaana
J
Rich
Jukka
J
Tuominen
Janne
J
Kylmä
Jukka
J
Seppälä
Showan N
SN
Nazhat
K Elizabeth
KE
Tanner
D000971:Antineoplastic Combined Chemotherapy Protocols; D018786:Bone Substitutes / Q000737:chemistry / Q000528:radiation effects / Q000592:standards; D002945:Cisplatin; D003188:Composite Resins / Q000737:chemistry* / Q000528:radiation effects / Q000592:standards; D005047:Etoposide; D005720:Gamma Rays; D006868:Hydrolysis; D019344:Lactic Acid; D008422:Materials Testing; D019563:Mechanics; D008942:Mitoxantrone; D011091:Polyesters / Q000528:radiation effects / Q000592:standards; D011140:Polyurethanes / Q000528:radiation effects / Q000592:standards; D012965:Sodium Chloride / Q000494:pharmacology; D013242:Sterilization; D013629:Tamoxifen
D018786:Bone Substitutes; D003188:Composite Resins; D011091:Polyesters; D011140:Polyurethanes; C081821:microthane foam; D013629:Tamoxifen; D019344:Lactic Acid; D012965:Sodium Chloride; D005047:Etoposide; D008942:Mitoxantrone; D002945:Cisplatin