Structure and properties Introduction Molecular structure and properties Crystalline polymers Preconditions of crystallization Crystalline structure Nucleation Melting Properties of crystalline polymers Structure of amorphous polymers

Introduction Flexible chains, structure Typical behavior Practical importance Interactions and its modification Plasticizing Crystalline polymers Heterogeneous structures in amorphous polymers

Molecular structure and properties Characteristic temperatures (Tm, Tg) Glass transition: flexibility of chain Determinant parameters Bond types in the chain Substituents (size, chemical structure) Intermolecular interactions

Molecular structure and properties The structure of main chain

Molecular structure and properties Size of the substituents

Molecular structure and properties Intermolecular interactions

Molecular structure and properties Plasicizing effect, secondary bonds – glass transition, cold resistance

Molecular structure and properties Melting temperature H-bonds in polyamides Regularity of structure (yes) – strength of H-bonds (no)

Molecular structure and properties Correlation

Crystalline polymers - preconditions Regular chain – chain regularity

Crystalline polymers – structural hierarchy Unit cell Unit cell Smallest regular unit Modification Lamella Thickness Spherulite Size Crystallinity Crystallite Lamella Spherulite Product Properties of crystalline polymers are determined by the crystalline structure

Crystalline polymers – unit cell PE, PVOH, cellulose PP, peptides, helical structure Polymorphism

Crystalline polymers – lamella Single crystal, fringed micelle or folded lamella

Crystalline polymers – spherulites Spherical superstructure of lamellas, PP (-modification)

Crystalline polymers – spherulites SEM micrograph of lamellas in a spherulite, orientation, thickness and properties

Crystalline polymers – cilindrites Row nuclei, transcrystalline structure, hedrit, sish-kebab structure

Crystalline polymers – nucleation, nucleating agents Homogeneous or heterogeneous nucleation, topology, shape of the nucleating agents

Crystalline polymers – crystallization melting, kinetics Melting point depends on the lamella thickness

Crystalline polymers – crystallization melting, kinetics Wide melting temperature range, supercooling, nucleation

Crystalline polymers – crystallization melting, kinetics Growth Thermodynamics Kinetics Overall rate of crystallization Avrami equation Constants (n, k)

Crystalline polymers – structure and properties Modification Crystallinity Lamella thickness Size of the spherulites Tie molecules

Crystalline polymers – structure and properties The number of tie molecules is proportional to the thickness of lamella

Crystalline polymers - orientation Large strength and stiffness in the direction of orientation

Amorphous polymers – ordered structures Heterogeneous structure, PVC, block copolymers