Presentation on polymers
Download as PPTX, PDF0 likes169 views
This document discusses polymers including their classification, types, characteristics, and applications. Polymers are large molecules composed of many repeating structural units. They can be natural, semi-synthetic, or synthetic and are classified based on source, structure, composition, polymerization method, molecular forces, and backbone chain. Common types include linear, branched, and cross-linked polymers as well as homopolymers and copolymers. Polymerization occurs through addition or condensation reactions. Polymers exhibit properties like being thermoplastic, thermosetting, or elastic. They have various applications in medicine, consumer goods, industry, and sports.
Presentation on polymers
- 2. a) Introduction b) Classification c) Types of Polymerizations d) Characteristics e) Applications
- 3. A word Polymer is a combination of two Greek words “Poly” means Many and “Meros” means Parts or units . Many of natural and synthetic compounds of usually high molecular weight consisting upto millions of repeated units , each a relatively light and simple molecule is known as a Polymer .
- 4. The following are the some common classification of Polymers : 1. By source 2. by structure 3. By composition 4. By mode of polymerization 5. By molecular force 6. By backbone of the chain
- 5. 1) Natural Polymers : They are found in plants and animals ( example Protein , cellulose,stach,resins and rubber) 2) Semi-synthetic Polymers : Cellulose derivatives are cellulose acetate (rayon) 3) Synthetic Polymers : Such as plastic (polythene), synthetic fibers (nylon 6,6), and synthetic rubbers (Buna-S) are examples of man-made polymers .
- 6. Linear Polymers : They consist of long and straight chains , the examples are high density polythene ,PVP, etc . They are commonly relatively soft . Branched Polymers : These polymers contain linear chains having some branches e.g. low density polythene Cross-linked Polymers : They are usually formed from bi-functional and tri-functional monomers and contain strong covalent bonds between various linear polymer chains e.g. vulcanized rubber, urea-formaldehyde resins etc. They are hard and don’t melt
- 7. Homopolymer: A polymer resulting from the polymerization of a single monomer ; a polymer consisting substantially of a single type of repeating unit . Copolymer : When two different types of monomers are joined in the same polymer chain , the polymer is called as a Copolymer.
- 8. Addition polymers : They are formed by direct addition of repeated monomers without the elimination of product molecules e.g. Polyethylene , PVC,teflon,PVP. Condensation Polymers: They are formed by the condensation of two (or) more monomers with the elimination of simple molecules like (H2o,NH3 HCL) e.g. Terylene,bakelite,alkyl resin, nylon 66 etc.
- 9. Thermoplastic: They are soften on heating and harden on cooling reversibly e.g. polyethylene,PVC,teflon Thermosetting: They undergo permanent change on heating e.g. Bakelite,Polyester Elastomers: They are amorphous with a high degree of elasticity e.g. Natural rubber Fibers: They have quite strong interparticle force such as H-bond with high tensile strength and high modulus e.g. Nylon and polyacrylontrile.
- 10. 1)Addition Polymerization: a) Initiation reaction. B) Propagation reaction . c) Termination reaction . 2) Condensation Polymerization .
- 11. LOW DENSITY. LOW COEFFICIENT OF FRICTION. GOOD CORROSION RESISTANCE. GOOD MOULD ABILITY. EXCELLENT SURFACE FINISH CAN BE OBTAINED. CAN BE PRODUCED WITH CLOSE DIMENSIONAL TOLERANCES. ECONOMICAL. POOR TENSILE STRENGTH. LOW MECHANICAL PROPERTIES. POOR TEMPERATURE RESISTANCE. CAN BE PRODUCED TRANSPARENT OR IN DIFFERENT COLOURS
- 12. Medicine Consumer science Industry Sport