Fibre Structure and Morphology
category
The structure of polyester fibres spans multiple length scales: molecular (chain conformation, orientation), crystalline (unit cell, crystallite size), lamellar (folded chain lamellae), and macrostructural (skin-core, cross-section shape). Structure is determined by processing history and directly determines all physical, mechanical, and chemical properties.
Role
Fibre structure–property relationships are the intellectual core of polymer fibre science. Understanding how processing creates structure, and how structure determines properties, is the foundation of rational fibre design and the basis of most academic research in fibre science.
Subtopics
- Two-Phase Model: Crystalline and Amorphous Regions The classical two-phase model of semicrystalline PET describes fibres as a composite of crystalline …
- Skin-Core Structure and Processing Effects Rapid surface quenching during melt spinning creates a skin layer (0.5–3 µm) with higher orientation…
- Fibrillar Structure and Microfibril Model High-resolution TEM and SAXS reveal polyester fibre structure as a fibrillar assembly: microfibrils …
- WAXD and SAXS Structural Characterisation Wide-angle X-ray diffraction (WAXD) provides crystallinity (from peak integration vs. amorphous halo…
- Cross-Section Geometry and Light Scattering Circular cross-section PET has characteristic bright lustre from specular reflection. Trilobal cross…
- Differential Scanning Calorimetry of Fibres DSC of PET fibres (10–20°C/min, N₂ atmosphere): measures Tg (step change in heat capacity, 67–80°C),…
- FTIR and Raman Spectroscopy of PET FTIR of PET: characteristic bands at 1715 cm⁻¹ (C=O stretch), 1245 cm⁻¹ (C–O–C stretch), 1018 cm⁻¹ (…
- Amorphous Orientation and Sonic Modulus Amorphous orientation (fa) is distinguished from crystalline orientation (fc) by comparing birefring…
- Fibre Surface Chemistry and Zeta Potential PET surface is hydrophobic (contact angle 70–80°), with low surface energy (43 mN/m). Surface contai…
- Nanostructure Characterisation by TEM and AFM Transmission electron microscopy (TEM) of RuO₄-stained thin sections reveals lamellar crystals, fibr…