Miscibility and hydrolytic degradation of bioreabsorbable blends of poly(p-dioxanone) and poly(L-lactic acid) prepared by fusion

• Published in: Journal of applied polymer science Vol. 101; no. 3; pp. 1899 - 1912
• Main Authors: Pezzin, A. P. T., Duek, E. A. R.
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 05.08.2006; Wiley
• Subjects: Applied sciences; biodegradable; Biological and medical sciences; blends; Electrical, magnetic and optical properties; Exact sciences and technology; Medical sciences; miscibility; Organic polymers; Physicochemistry of polymers; polyesters; Properties and characterization; Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases; Technology. Biomaterials. Equipments; Thermal and thermodynamic properties; Biodegradation; Biological properties; biodegradable; Polymer blends; Property composition relationship; Biodegradability; Absorbable; Semicrystalline polymer; Experimental study; Lactone polymer; Heterogeneous mixture; Structure composition relationship; Thermal stability; polyesters; Hydrolysis; Thermal properties; Lactic acid polymer; Dynamic mechanical properties; Morphology; Aliphatic polymer; Miscibility; Biomaterial; Thermodynamic properties; blends
• ISSN: 0021-8995; 1097-4628
• DOI: 10.1002/app.23646

Blends of two semicrystalline polymers, poly(L‐lactic acid) (PLLA) and poly(p‐dioxanone) (PPD), were prepared by melting the polymers in different proportions. The miscibility, thermal behavior, dynamic‐mechanical properties, and morphology of these blends were studied using differential scanning calorimetry (DSC), dynamic‐mechanical analysis (DMA), and scanning electron microscopy (SEM). The melting temperature of PPD, determined by DSC, did not change with increasing PLLA content, suggesting that this system was immiscible. The presence of two glass transition temperatures detected by DMA also indicated the total immiscibility of the two polymers and this phase separation was confirmed by SEM. The stability of blends immersed in tubes containing phosphate buffer (pH = 7.4) in a thermally controlled bath at (37 ± 1)°C was assessed using DSC, thermogravimetric analysis (TGA), and SEM. PLLA degraded more slowly than PPD, whereas the blends had a degradation rate that was intermediate to these two polymers. This finding indicated that it was possible to control the degradation rate of the blend by changing its composition. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1899–1912, 2006