Polycaprolactone (PCL) is an organic, biodegradable polyester produced through the ring-opening polymerization (ROP) of the monomer ε-caprolactone.
Structure of Polycaprolactone (PCL)
The chemical formula of its repeating unit is:
(C₆H₁₀O₂)ₙ
PCL has a semi-crystalline chain structure with flexible polymer chains and a relatively low melting temperature (around 60°C), allowing it to be easily blended with other polymers and reinforcing materials.
Properties of Polycaprolactone
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Low melting temperature: approximately 58–63°C
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Glass transition temperature (Tg): around –60°C
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Excellent processability: suitable for injection molding, extrusion, and 3D printing
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Biodegradability: decomposes under environmental or industrial composting conditions
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Biocompatibility: suitable for medical and pharmaceutical applications
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High flexibility: retains elasticity even at low temperatures
Applications of Polycaprolactone
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Medical and pharmaceutical uses: absorbable sutures, drug delivery systems, tissue engineering scaffolds
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3D printing and rapid prototyping: due to its low melting temperature and precise printability
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Biodegradable products: compostable bags, packaging, and films
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Polymer blending: used as an additive to improve flexibility or lower the melting point of other polymers such as PLA
Advantages of Polycaprolactone
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Biodegradable and environmentally friendly
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Flexible even at low temperatures
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Excellent compatibility with other polymers
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Non-toxic and safe for medical applications
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Good dimensional stability during processing
Disadvantages of Polycaprolactone
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Relatively high production cost compared to common polymers
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Low melting temperature, making it unsuitable for high-temperature applications
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Slow degradation rate under natural conditions (without industrial composting)
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Lower mechanical strength compared to some thermoplastics such as PET or ABS
