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ABSTRACT This study investigates the morphological, thermal, mechanical, and bioactive properties of centrifugally spun fibrous composites made from poly(D,L‐lactide)/poly(3‐hydroxybutyrate) (PLA/PHB) blends with zinc oxide (ZnO) and hydroxyapatite (Hap) nanoparticles. A 75/25 PLA/PHB weight ratio was chosen to balance mechanical and thermal properties. The precursor solution viscosities ranged from 0.25 to 0.50 Pa s, increasing with nanoparticle incorporation probably due to polymer‐nanoparticle interactions. SEM revealed a uniform fibrous morphology, with diameters of 1.21 for PLA/PHB, 2.65 for PLA/ZnO/Hap, and 1.80 μm for PLA/PHB/ZnO/Hap. TGA showed two‐step degradation for PLA/PHB fibers, while PLA/PHB/ZnO/Hap degraded in a single step at 249°C, leaving a residue of 9.95%. DSC indicated partial miscibility, with cold crystallization at 85°C (enthalpy: 7.72 J/g), slightly modified by nanoparticle addition. PLA/PHB fibers achieved a Young's modulus of 24.96 ± 3.91 MPa, three times that of pure PLA, but adding ZnO and Hap reduced modulus and tensile strength to 6.03 and 0.29 MPa, retaining suitability for biomedical applications. PLA/PHB/ZnO/Hap fibers exhibited 90%Escherichia coligrowth inhibition and enhanced MC3T3‐E1 cell viability by 120% on day 7. These results highlight their potential for antimicrobial, biocompatible medical devices.
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Structure and Growth Habits of Solution-Grown Single Crystals of a Random Copolymer, Poly[(R)-3-hydroxybutyrate-co-(R)-3-hydroxyhexanoate]
Single crystals of a random copolymer, Poly[(R)-3-hydroxybutyrate-co-(R)-3-hydroxyhexanoate] (PHBHx), with a relatively high (R)-3-hydroxyhexanoate (3HHx) content of 3.9 mol% were grown from dilute solutions over a wide range of crystallization temperatures (Tc) from -20 °C to 75 °C. Unlike Poly[(R)-3-hydroxybutyrate-co-(R)-3-hydroxyvalerate] (PHBV) which allows the 3-hydroxyvalerate (3HV) to be included into PHB lattice, 3HHx is excluded from the lattice as a non-crystallizable molecular defect. Remarkably, however, even at such a high defect content, all the samples (except for Tc = -20 °C) formed well-developed needle-shaped single crystals, with a crystal morphology similar to that found for crystals of the homopolymer PHB.
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- Award ID(s):
- 1809977
- PAR ID:
- 10099246
- Date Published:
- Journal Name:
- Polymer
- Volume:
- 154
- ISSN:
- 0032-3861
- Page Range / eLocation ID:
- 111 - 118
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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