کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5202619 | 1381905 | 2011 | 8 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Influence of hydrolytic degradation on the surface properties of poly-5d/95l-lactide resorbable bone plates
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آلی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
This study explores in vitro aging effects on the surface properties of resorbable PLA95 (poly-5d/95l-lactide) bone plates. The in vitro degradation of injection molded PLA95 bone plates was undertaken by soaking them in a PBS solution. Specimens were harvested at 0, 4, 6, 8, 12, 20, and 26 weeks. After each in vitro aging period, the surface morphology, viscosity, chemical structure, wettability, and thermal properties of the PLA95 bone plates were examined by scanning electron microscopy (SEM), capillary viscometers, attenuated total reflection fourier transform infrared spectroscopy (ATR-FTIR), contact angle, and modulated differential scanning calorimetry (MDSC), respectively. The surface morphology of aged PLA95 bone plates exhibited bulk erosion. As hydrolysis progressed, the inherent viscosity (I.V.) of the PLA95 plates gradually decreased from 0.83 ± 0.01 dL/g at week 0-0.46 ± 0.03 dL/g at week 26. However, the absorbance peak intensity ratio between δas CH3 (A1452 cmâ1) and ν CO (A1750 cmâ1) and the contact angle reveal different tendencies than that of molecular weight, which decreases. The contact angle of the PLA95 plates decreased until week 4, increased until week 8, and subsequently decreased again. Peak separation analysis reveals that the equilibrium part of the modulated DSC overlapped curves exhibit triple endothermic peaks. Over time, in vitro degradation changes the position and area of the individual peaks. After different time periods of degradation, the variation of wettability shows a tendency similar to the change of PLA95 plates crystallinity; the intensity ratio of A1452 cmâ1 and A1750 cmâ1 (δas CH3/ν CO) absorbance peaks varied like the ratio of β/α-crystal heat of fusion. Results also show a similarity in the degradation time dependence in MDSC, contact angle, and ATR-FTIR measurements. During the in vitro aging process, the breakdown and subsequent recrystallization of PLA95 molecular chains might be attributed to a progressive change in wettability and the molecular conformation between δas CH3 and ν CO.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Polymer Degradation and Stability - Volume 96, Issue 8, August 2011, Pages 1522-1529
Journal: Polymer Degradation and Stability - Volume 96, Issue 8, August 2011, Pages 1522-1529
نویسندگان
Hsin-Tai Hu, Tsai-Chin Shin, Sheng-Yang Lee, Chien-Chung Chen, Jen-Chang Yang,