PHYSICAL & CHEMICAL PROPERTIES OF POLYMER.pptx

Melting point, boiling point, strength, hardness, density, color, opaqueness, transparency, and electrical conductivity are among the physical properties they might mention. Chemical reactivity such as combustion and biodegradability are common chemical properties.

1. DENSITY & CRYSTALLINITY Physical properties of polymers

2. OUTLINE POLYMER STRUCTURE CHARACTERIZATION OF POLYMER TYPES OF POLYMER STRUCTURE TACTICITY GEOMETRIC ISOMERISM PHYSICAL PROPERTIES OF POLYMERS OTHER PROPERTIES OF POLYMERS CHEMICAL PROPERTIES OF POLYMERS

3. Polymer structure is the arrangement of the repeating identical unit called monomers. This structure is what helps define the physical and chemical properties of a polymer. POLYMER STRUCTURE

4. CHARACTERIZATION OF POLYMER Linear Branched Cross link Network

5. TYPES OF POLYMER STRUCTURE Homogenous POLYMERS contains only one repeating monomer AND IT involve A pure monomer or homogeneous solutions of monomer and polymer in a solvent . Heterogenous polymers can be classified into copolymers and terpolymers . Polymers with two different repeating units in their chains are called copolymers.

6. TACTICITY Tacticity is based on the arrangement of the pendant group along the hydrocarbon chain. It can be classified into ; Isotactic polymer Syndiotactic polymer Atactic polymer

7. Cis-but-2-ene Geometric isomerism occurs due to the restricted rotation in unsaturated hydrocarbons. It is also known as Cis – trans  isomerism Trans-but-2-ene Geometric Isomerism

8. De gree of polymerization M olecular weight Tensile Strength Elasticity Crystallinity Density PHYSICAL PROPERTIES OF POLYMERS

9. The degree of polymerization (DP)-n in a polymer molecule is defined as the number of repeating units in the polymer chain. It is the number of monomeric units in a polymer molecule −(−CH − CH −)−n DEGREE OF POLYMERIZATION

10. MOLECULAR WEIGHT molecular mass which is the mass of a molecule of a substance, based on 12 as the atomic weight of carbon-12.  

11. MOLECULAR WEIGHT   Suppose we have a set of values { x 1 , x 2 , …, x n } and the corresponding probability of occurrence is given by { P 1 , P 2 , …, P n }, then the average value is defined as follows:

12. M N M W Molecular weight Weight fraction MOLECULAR WEIGHT FIGURE Number average molecular weight Molecular weight of the repeat unit DP = A typical plot showing the number-average and weight-average molecular weight

13. The strength of a polymer to elongate without breaking is its tensile strength. Physical strength and durability depend on this property of polymers Tensile Strength

14. Polymers with weak intermolecular bonds stretch to a greater extent and are more elastic. ELASTICITY

15. CRYSTALLINITY The crystallinity of a polymer refers to the degree to which the polymer chains are linked with each other.

16. Polymers with less crystallinity are more useful as they are brittle. This property is based on the type of arrangement of polymeric chains. It’s constituents are arranged in a highly ordered microscopic structure, forming a crystal lattice  grains are separated by grain boundaries and normally have random crystallographic orientations. The atoms and molecules are not organized in a definite lattice pattern

17. DENSITY defined as the ratio of molar mass and molar volume at a given temperature and pressure.

18. DENSITY DIFFERENCES LDPE LDPE is softer and more flexible than HDPE. It also has a lower melting point (115° C) and is more transparent. HDPE HDPE is more likely to crack under stress and is rigid, also durable and offers greater chemical resistance. . Based on the density differences, p olymers are classified into high-density polymers and low-density polymers

19. Other Properties of Polymers Heat capacity Thermal expansion Resistance to Electric current Refractive index  

20. Other Properties of Polymers depend on several factors. Some of them are discussed below: Temperature Temperature sensitive polymers lose their compressive strength and flexibility as the temperature rises. As the temperature rises, the molecules' kinetic energy rises and Young's modulus decreases.

21. It can be inferred that as the chain length of polymers increases, their strength also increases. CHAIN LENGTH

22. BRANCHING As branching increases, the mechanical strength of polymers also increases. For example, the degree of crystallinity is high density polyethylene and has relatively poor mechanical properties. Thus branching makes polymers stiffer, harder and stronger.

23. CROSS LINKING When polymer chains are cross-linked extensively by strong covalent bonds, their strength increases, making it difficult to melt them

24. The presence of polar side-groups increases the strength of attraction between the polymeric chains, making them stronger due to hydrogen bonding and other attractive forces. NATURE OF SIDE GROUPS

25. CHEMICAL PROPERTIES OF POLYMERS Bonding and reactivity Biodegradability Interaction between the reactive groups Adhesion

26. CHEMICAL PROPERTIES OF POLYMERS BONDING & REACTIVITY  The strong covalent bond determine its property like reactivity.

27. CHEMICAL PROPERTIES OF POLYMERS The hydrogen bond is formed by the carbon- yl group located on the side chains of the monomers. INTERACTION BETWEEN THE REACTIVE GROUPS

28. CHEMICAL PROPERTIES OF POLYMERS Adhesion refers to the tendency of various surfaces to bind with one together. ADEHESION

29. CHEMICAL PROPERTIES OF POLYMERS Decomposers have the ability to breakdown polymers. Natural polymers, such as rubber, are biodegradable, but manufactured polymers are not. BIODEGRADABILITY