Post-drawn PCL nanofibers can be molecularly tuned to have a variety of mechanical properties and drug release profiles depending on the temperature and time of annealing, which has implications for regenerative medicine and drug delivery applications. Post-drawing polycaprolactone (PCL) nanofibers has previously been demonstrated to drastically increase their mechanical properties. Here the effects of annealing on post-drawn PCL nanofibers are characterized. It is shown that room temperature storage and in vivo temperatures increase crystallinity significantly on the order of weeks, and that high temperature annealing near melt significantly increases crystallinity and molecular orientation on the order of minutes. The kinetics of crystallization were assessed using an anneal and quench approach. High temperature annealing also increased the ultimate tensile strength and toughness of the fibers and changed the release profile of a model drug absorbed in PCL nanofibers from first-order to zero-order kinetics.
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Non-Isothermal Crystallization Kinetics of Poly (ɛ-Caprolactone) (PCL) and MgO Incorporated PCL Nanofibers
The study delves into the kinetics of non-isothermal crystallization of Poly (ɛ-caprolactone) (PCL) and MgO-incorporated PCL nanofibers with varying cooling rates. Differential Scanning Calorimetry (DSC-3) was used to acquire crystallization information and investigate the kinetics behavior of the two types of nanofibers under different cooling rates ranging from 0.5–5 K/min. The results show that the crystallization rate decreases at higher crystallization temperatures. Furthermore, the parameters of non-isothermal crystallization kinetics were investigated via several mathematical models, including Jeziorny and Mo’s models. Mo’s approach was suitable to describe the nanofibers’ overall non-isothermal crystallization process. In addition, the Kissinger and Friedman methods were used to calculate the activation energy of bulk-PCL, PCL, and MgO-PCL nanofibers. The result showed that the activation energy of bulk-PCL was comparatively lower than that of nanofibers. The investigation of the kinetics of crystallization plays a crucial role in optimizing manufacturing processes and enhancing the overall performance of nanofibers.
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- Award ID(s):
- 2200423
- PAR ID:
- 10528486
- Publisher / Repository:
- MDPI AG
- Date Published:
- Journal Name:
- Polymers
- Volume:
- 15
- Issue:
- 14
- ISSN:
- 2073-4360
- Page Range / eLocation ID:
- 3013
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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