NPTEL Syllabus

Structure and Properties of Fibres - Webcourse

COURSE OUTLINE

Introduction to fibers : definition, primary and secondary properties for textileapplications; Factors affecting fiber/polymer properties: Chemical structure,Physical Structure and Supramolecular Structure.

Molecular architecture, configuration, conformation, amorphous and crystallinephases, glass transition, plasticization, crystallization, melting, factors affectingglass transition temperature (Tg) and melting temperature (Tm ).

Essential requirements of fibre forming polymers, examples of fiber formingpolymers; Role of molecular entanglement on fibre formation; Basic structure ofa fiber-one dimensional, oriented, semi crystalline, structure of fibrils, FiberStructure Models.

General properties of fibres such as density, moisture absorption, tenacity,elongation, initial modulus, yield point, toughness, elastic recovery, creep, ands tress relaxation; Moisture Relations, Theory of mechanical properties,Viscoelasticity, Electrical and Optical Properties.

Fiber Characterization using Density, Wide Angle X Ray Diffraction (WAXD),Differential scanning calorimetry (DSC), Thermogravimetric Analysis (TGA),Thermomechanical Analysis (TMA) / Dynamic Mechanical analysis (DMA),Fourier Transform Infrared Spectroscopy (FTIR) and birefringence as methods ofinvestigating structure of fibers.

Basic methods of formation of man-made fibers - melt spinning, solution wetspinning, solution dry spinning. Formation of structures in viscose andthermoplastic fibers i.e. PET, nylon, PP, and acrylic.

COURSE DETAIL

S.No Topics No. ofLectures

1 Introduction to fibers : definition, classification, importantprimary and secondary properties for textileapplications.

2

2 General Concepts on Polymers : Type of Polymers :homo and co polymers Types of Copolymers - random,alternating, graft and block.

Polymerisation : addition and condensation, Bonding inPolymers : primary and secondary bonding ; Polymersas Plastics, fibers and rubbers.

1

3 General : An introduction to fibre structure andrequirements of fibre forming polymers, examples of fiberforming polymers.

Role of molecular entanglement fibre formation, Conceptof Anisotropy in bonding and molecular dimensions in

1

NPTELhttp://nptel.iitm.ac.in

Textile Engineering

Pre-requisites:

Introductory course on "Textile Fibres"

Additional Reading:

1. Handbook of Textile FibersVolume 1 & 2 J Gordon CookWoodhead Publishing Ltd.Cambridge UK (2001).

2. Hand Book of Fiber ChemistryMeenachem Lewin InternationalFiber Science and TechnologySeries (15).

Coordinators:

Dr. Mangala JoshiDepartment of Textile TechnologyIITDelhi

Prof. B.L. DeopuraDepartment of Textile TechnologyIITDelhi

of Anisotropy in bonding and molecular dimensions inpolymers, Cohesive energy density.

4 Factors affecting polymer/fiber properties : Chemicalstructure and Physical Properties.

Molecular weight and Distribution ,Polydispersity Index ,Molecular architecture, configuration, conformation,Tacticity and Stereoregularity, amorphous andcrystalline phases, Molecular Orientation.

2

5 Crystallisation in Polymers:Importance, Factors affectingCrystallisation Mechanism : Nucleation and Growth,Type of crystallization : Lamellar and SphreuliticStructures.

Crystallisation in Fibers forming polymers; Rate ofCrystallisation.

2

6 Factors affecting polymer/fiber properties :Supramolecular Morphology, Semicrystalline nature :Basic structure of a fiber - one dimensional, oriented, secrystalline, structure of fibrils, Fiber Structure Models.

2

7 Glass transition, plasticization, crystallization, melting,factors affecting glass transition temperature (Tg) andmelting temperature (Tm); Tg and Tm of fibre formingpolymers.

2

8 General properties of fibres such as density, moistureabsorption, tenacity, elongation, initial modulus, yieldpoint, toughness, elastic recovery, creep and stressrelaxation.

2

9 Fiber Characterization Techniques using Density, WideAngle X Ray Diffraction (WAXD), Differential scanningcalorimetry (DSC), Thermogravimetric Analysis (TGA).

Thermomechanical Analysis (TMA) / DynamicMechanical analysis (DMA), Fourier Transform InfraredSpectroscopy (FTIR) and birefringence as methods ofinvestigating structure of fibers.

8

10 Mechanical Properties : Mechanism of deformation infibres, Stress-strain relations, Yield and fracture , Elasticrecovery , Theory of mechanical properties

5

11 Principles of Elasticity and viscoelasticity, ViscoelasticModels : Maxwell model,Kelvin Model, Eyring Model.

3

12 Creep and Stress relaxation in fibres : Time Effects. 2

13 Moisture Relations:Moisture sorption and desorption infibres, Sorption isotherm Molecular Explanation ofHysteresis, Rate of moisture Diffusion , Heats ofsorption, Swelling and Theories of moisture sorption.

4

14 Electrical Properties: Dielectric properties, effect offrequency and temperature on dielectricconstant.Electrical resistance and its measurement,staticelectricity and measurement of static charge in fibres .

2

15 Thermal Properties: Thermal expansion. Specific Heat,Thermal conductivity.

1

16 Optical properties: Polarizability and refractive index,Birefringence and its measurement, HermantzOrientation Factor, Absorption and Dichroism , Reflexionand Lustre.

1

References:

1. Introduction to Polymers - Robert J. Young & P A Lovell.

2. Physical Properties of Textile Fibers - W.E. Morton & J.W.S. Hearle.

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