Surface Morphology and Degradation of Poly[(R)-3-Hydroxybutyrate]-block-Poly(ε-Caprolactone) and Poly[(R)-3-Hydroxybutyrate]-block-Poly(l-Lactide) Biodegradable Diblock Copolymers
Abstract
:1. Introduction
2. Materials and Methods
2.1. Materials
2.2. Synthesis of PHBCL and PHBLA Diblock Copolymers
2.2.1. Synthesis of LMPHB Initiator
2.2.2. ROP of ε-CL and l-Lactide Cyclic Monomers
2.3. Structural Analysis (1H NMR and GPC)
2.4. Thermal Analysis (DSC, TGA and WAXD)
2.5. WAXD Measurements
2.6. POM Observation
2.7. Melt-Crystallized Thin-Film Sample Preparation
2.8. AFM Observation
2.9. Enzymatic Degradation
3. Results and Discussion
3.1. Synthesis and Characterization of Diblock Copolymers
3.2. Thermal Analysis
3.2.1. DSC (Thermal Properties)
3.2.2. WAXD
3.2.3. TGA
3.3. Crystallization Analysis
3.3.1. DSC (Crystallization)
3.3.2. POM Observation of Crystallization
3.4. AFM Observation of Surface Morphology Analysis
3.5. Effects of Enzymatic Degradation on Surface Morphology
4. Conclusions
Supplementary Materials
Author Contributions
Funding
Institutional Review Board Statement
Data Availability Statement
Acknowledgments
Conflicts of Interest
Abbreviations
P3HB (or PHB) | Poly[(R)-3-hydroxybutyrate] |
PCL | Polycaprolactone |
PLLA (or PLA) | Poly(l-lactic acid) |
LMPHB | Low molecular weight poly[(R)-3-hydroxybutyrate] |
HMPHB | High molecular weight poly[(R)-3-hydroxybutyrate] |
PHBCL | Poly[(R)-3-hydroxybutyrate]-block-polycaprolactone |
PHBLA | Poly[(R)-3-hydroxybutyrate]-block-polylactic acid |
NMR | Nuclear magnetic resonance |
GPC | Gas permeation chromatography |
DSC | Differential scanning calorimetry |
TGA | Thermal gravimetric analysis |
DTG | Derivative thermogravimetric analysis |
WAXD | Wide-angle X-ray diffraction |
POM | Polarized optical microscopy |
AFM | Atomic force microscopy |
ROP | Ring- opening polymerization |
DBTDL | Dibutyltin dilaurate |
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Target of Degradation | Enzyme | Enzyme (with Buffer) Solution | Volume of Enzyme Solution (μL) | Degradation Time (min) |
---|---|---|---|---|
PHB | PHB depolymerase | 1.0 μg/mL in 0.1 M phosphate buffer | 100 | 40 |
PCL | Lipase | 1.0 mg/mL in 0.1 M phosphate buffer | 75 | 30 |
PLA | Proteinase K | 0.2 mg/mL in 50 mM tris-HCl buffer | 100 | 120 |
Sample | PHB:PCL/PLA a | Mn (g mol−1) a | Mn (g mol−1) b | Mw (g mol−1) b | Mw/Mnb | Yield (%) |
---|---|---|---|---|---|---|
HMPHB | - | - | 174,200 | 430,300 | 2.47 | - |
LMPHB | - | 10,800 | 26,000 | 38,400 | 1.48 | 94 |
PHBCL 0.5CL | 1:0.5 | - | 34,900 | 44,700 | 1.28 | 93 |
PHBCL 1.0CL | 1:1.0 | - | 49,200 | 58,300 | 1.19 | 92 |
PHBCL 2.0CL | 1:2.1 | - | 73,200 | 84,600 | 1.16 | 95 |
PHBLA 0.5LA | 1:0.7 | - | 29,100 | 40,300 | 1.39 | 85 |
PHBLA 1.0LA | 1:1.3 | - | 39,100 | 47,400 | 1.21 | 87 |
PHBLA 2.0LA | 1:2.4 | - | 59,000 | 68,200 | 1.16 | 86 |
Sample | Tm (°C) a | ΔHm (J g−1) a | Tg (°C) b | Td5% (°C) c | Td50% (°C) c | Tdmax (°C) c | Xc (%) d | |||
---|---|---|---|---|---|---|---|---|---|---|
PHB | PCL/ PLA + PHB | PHB | PCL/ PLA + PHB | PHB | PCL/ PLA + PHB | |||||
PHBCL 0.5CL | 166.9 | 47.0, 57.3 | 65.8 | 5.6, 2.0 | −6.9 | - | 271 | 301 | 407 | 73.5 ± 5 |
PHBCL 1.0CL | 168.5 | 58.0 | 56.2 | 40.5 | −3.5 | −55.0 | 284 | 378 | 406 | 65.5 ± 6 |
PHBCL 2.0CL | 168.9 | 58.3 | 32.6 | 50.5 | −7.8 | −53.3 | 290 | 396 | 406 | 73.5 ± 5 |
PHBLA 0.5LA | - | 165.5 | - | 87.4 | - | 10.4 | 273 | 297 | 359 | 62.5 ± 4 |
PHBLA 1.0LA | - | 165.8 | - | 80.7 | - | 20.2 | 281 | 310 | 360 | 56.5 ± 5 |
PHBLA 2.0LA | - | 172.3 | - | 67.4 | - | 34.5 | 284 | 346 | 365 | 56.5 ± 5 |
Sample | Tc (°C) a | ΔHc (J g−1) a | Tm (°C) b | ΔHf (J g−1) b | ||||
---|---|---|---|---|---|---|---|---|
PHB/ PHB + PLA | PCL/PLA | PHB/ PHB + PLA | PCL/PLA | PHB/ PHB + PLA | PCL/PLA | PHB/ PHB + PLA | PCL/PLA | |
PHBCL 0.5CL | 85.2 | 7.3 | −36.8 | −9.8 | 176.1 | 51.3 | 55.8 | 20.7 |
PHBCL 1.0CL | 77.3 | 28.1 | −19.9 | −29.5 | 177.9 | 59.8 | 48.6 | 27.8 |
PHBCL 2.0CL | 51.2 | 31.2 | −0.5 | −41.0 | 178.3 | 61.6 | 28.6 | 33.6 |
PHBLA 0.5LA | 88.5 | - | −44.5 | - | 173.5 | - | 59.6 | - |
PHBLA 1.0LA | 82.6 | - | −35.8 | - | 174.0 | - | 59.9 | - |
PHBLA 2.0LA | - | 99.6 | - | −13.1 | 180.1 | - | 60.1 | - |
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Bartels-Ellis, A.; Hayashi, S.; Hiraishi, T.; Tsuge, T.; Abe, H. Surface Morphology and Degradation of Poly[(R)-3-Hydroxybutyrate]-block-Poly(ε-Caprolactone) and Poly[(R)-3-Hydroxybutyrate]-block-Poly(l-Lactide) Biodegradable Diblock Copolymers. Polymers 2025, 17, 1558. https://doi.org/10.3390/polym17111558
Bartels-Ellis A, Hayashi S, Hiraishi T, Tsuge T, Abe H. Surface Morphology and Degradation of Poly[(R)-3-Hydroxybutyrate]-block-Poly(ε-Caprolactone) and Poly[(R)-3-Hydroxybutyrate]-block-Poly(l-Lactide) Biodegradable Diblock Copolymers. Polymers. 2025; 17(11):1558. https://doi.org/10.3390/polym17111558
Chicago/Turabian StyleBartels-Ellis, Ayan, Senri Hayashi, Tomohiro Hiraishi, Takeharu Tsuge, and Hideki Abe. 2025. "Surface Morphology and Degradation of Poly[(R)-3-Hydroxybutyrate]-block-Poly(ε-Caprolactone) and Poly[(R)-3-Hydroxybutyrate]-block-Poly(l-Lactide) Biodegradable Diblock Copolymers" Polymers 17, no. 11: 1558. https://doi.org/10.3390/polym17111558
APA StyleBartels-Ellis, A., Hayashi, S., Hiraishi, T., Tsuge, T., & Abe, H. (2025). Surface Morphology and Degradation of Poly[(R)-3-Hydroxybutyrate]-block-Poly(ε-Caprolactone) and Poly[(R)-3-Hydroxybutyrate]-block-Poly(l-Lactide) Biodegradable Diblock Copolymers. Polymers, 17(11), 1558. https://doi.org/10.3390/polym17111558