1. Polymer Technology

2. introduction Definition: Chemistry of high polymer is the science dealing with the structure, properties and uses of molecules. Chemistry of high polymer is the science dealing with the structure, properties and uses of molecules.

3. The word polymer consists of two segments, poly which means many and mer which means parts. This means that the polymer molecule is built up of repetition of simple units known as the basic structure units or the building blocks. The molecules which is build up of building block is known as monomer, if it contains two blocks it is a dimer then a trimer, tetramer and finally a polymer. The word polymer consists of two segments, poly which means many and mer which means parts. This means that the polymer molecule is built up of repetition of simple units known as the basic structure units or the building blocks. The molecules which is build up of building block is known as monomer, if it contains two blocks it is a dimer then a trimer, tetramer and finally a polymer.

4. Our clothes, houses and food are made of macromolecules. the most two essential kinds of matter, that is cellulose and protein are made of macromolecules.This means that all plants and animal are made up of high polymer and the chemical reactions involved in the life. Our clothes, houses and food are made of macromolecules. the most two essential kinds of matter, that is cellulose and protein are made of macromolecules.This means that all plants and animal are made up of high polymer and the chemical reactions involved in the life.

5. Classification: There are no general methods for classification of high polymers and the all methods are overlapping each other and one polymer may find a place in more than one subdivision as may be seen: There are no general methods for classification of high polymers and the all methods are overlapping each other and one polymer may find a place in more than one subdivision as may be seen:

6. Classification according to origin Chemicalclassification. According to the shape of the shape of the polymeric chains Modified high polymer Three- dimensional or or cross-linked polymers cross-linked polymersBranchedpolymers Linear or thread- shaped polymers Classifications

7. Classification according to origin. Natural polymer: Natural polymer: these constitute the most abundant and important group of polymers, they are formed in the life processes of plants and animals and can be used as such without modification.

8. Modified high polymer: Modified high polymer: these are high polymers which utilize the molecular structure of natural macromolecules after their chemical modification so as to be suitable for industrial application.

9. Synthetic polymers: Synthetic polymers: These polymers do not occur in nature but they are synthesized from low molecular weight. These polymers do not occur in nature but they are synthesized from low molecular weight.

10. Chemical classification. 1- Carbon chain polymers: in which the backbone chains are composed only of carbon atoms, e.g. polyethylene, polystyrene & natural rubber.

11. 2- Hetero chain polymers: in which the backbone chains contain in addition to carbon atoms, atoms of other elements such as O, N, S, or P. Examples are polyamides, polyesters, proteins, phenolics & many others.

12. 3- Organo-metallic polymers: in which the backbone chains contain atoms of Si or Ti or other elements, e.g. hemoglobin and glass.

13. According to the shape of the polymeric chains: Linear or thread-shaped polymers: Linear or thread-shaped polymers: in which the macromolecules are in the form of threads having no branches. in which the macromolecules are in the form of threads having no branches.

14. Branched polymers: Branched polymers: in which to the backbone chains are attached some branches shorter in length and similar to or different in chemical constitution of the main chain. in which to the backbone chains are attached some branches shorter in length and similar to or different in chemical constitution of the main chain.

15. Three-dimensional or cross-linked polymers: Three-dimensional or cross-linked polymers: in this case the principle chains attached to each other by stable covalent bonds forming cross links. in this case the principle chains attached to each other by stable covalent bonds forming cross links.

16. Scientific Terms elastomer elastomer is a polymer with the property of elasticity. The term, which is derived from elastic polymer, is often used interchangeably with the term rubber, and is preferred when referring to vulcanizates. Each of the monomers which link to form the polymer is usually made of carbon, hydrogen, oxygen and/or silicon. Elastomers are existing above their glass transition temperature, so that considerable segmental motion is possible. is a polymer with the property of elasticity. The term, which is derived from elastic polymer, is often used interchangeably with the term rubber, and is preferred when referring to vulcanizates. Each of the monomers which link to form the polymer is usually made of carbon, hydrogen, oxygen and/or silicon. Elastomers are existing above their glass transition temperature, so that considerable segmental motion is possible.

17. The glass transition temperature( Tg ): is the temperature at which an amorphous is the temperature at which an amorphous solid, such as glass or a polymer, becomes brittle on cooling, or soft on heating solid, such as glass or a polymer, becomes brittle on cooling, or soft on heating

18. Latex Refers generically to a stable dispersion emulsion of polymer microparticles in an aqueous medium Refers generically to a stable dispersion emulsion of polymer microparticles in an aqueous medium

19. Mechanical Properties mechanical behavior of polymer, that is, its deformation and flow characteristics under stress. The mechanical behavior of a polymer can be characterized by its stress–strain properties

20. The results are usually shown as a plot of the stress versus elongation (strain).

21. Modulus. The resistance to deformation as measured by the initial stress divided by. Ultimate Strength or Tensile Strength. The stress required to rupture the sample. Ultimate Elongation. The extent of elongation at the point where the sample ruptures. Elastic Elongation. The elasticity as measured by the extent of reversible elongation.

22. Crystalline and Amorphous Behavior The terms crystalline and amorphous are used to indicate the ordered and unordered polymer regions, respectively.

23. Chemical background Theoretical aspects of polymer- forming reactions Polymers are obtained from monomers having at least two functional groups. The double bond can be opened to form two active centers and similarly a cyclic compound when one of its single bonds is ruptured.

25. CLASSIFICATION OF POLYMERIZATION REACTIONS CLASSIFICATION Condensationaddition FREE RADICAL MECHANISM CationicAnionic

26. in which the molecular formula of the structural unit (or units)lacks certain atoms present in the monomer from which it is formed, or to which it may be degraded by chemical means. Condensation polymers

27. Examples

29. addition polymers in which the molecular formula of the structural unit (or units) is identical with that of the monomer from which thepolymer is derived.

30. EMULSION POLYMERIZATION Polymerization in aqueous emulsions, which has been widely developed technologically, represents a special case of free radical chain Most emulsion polymerization systems comprise a water-insoluble monomer in water with a surfactant and a free radical initiator.

33. VULCANIZATION DEFINITION is a process generally applied to rubbery or elastomeric materials. These materials forcibly retract to their approximately original shape after a rather large mechanically imposed deformation.

42. Chemical technology Rubber technology Rubber technology Fiber technology Fiber technology Plastic technology Plastic technology

43. Rubber technology

44. Definition : A material that is capable of recovering from large deformations quickly and forcibly, and can be, or already is, modified to a state in which it is essentially insoluble in boiling solvent A material that is capable of recovering from large deformations quickly and forcibly, and can be, or already is, modified to a state in which it is essentially insoluble in boiling solvent

45. Classification of rubber Natural rubber Synthetic rubber

46. Natural rubber Definition : Natural rubber is an elastomer —an elastic hydrocarbon polymer—that was originally derived from a a milky colloidal suspension, or latex, found in the sap of some plants. The purified form of natural rubber is the chemical polyisoprene which can also be produced synthetically. Natural rubber is used extensively in many applications and products. The entropy model of rubber was developed in 1934 by Werner Kuhn Natural rubber is an elastomer —an elastic hydrocarbon polymer—that was originally derived from a a milky colloidal suspension, or latex, found in the sap of some plants. The purified form of natural rubber is the chemical polyisoprene which can also be produced synthetically. Natural rubber is used extensively in many applications and products. The entropy model of rubber was developed in 1934 by Werner Kuhn

47. Natural rubber Is extracted from the lattice of some trees present in the forests. Is extracted from the lattice of some trees present in the forests. The natural rubber is poly isoprene and depending on the type of tree we can find the cis and trans isomer The natural rubber is poly isoprene and depending on the type of tree we can find the cis and trans isomer

49. Proparties Rubber exhibits unique physical and chemical properties. Rubber's stress- strain behavior exhibits the Mullins effect, the Payne effect and is often modeled as hyper elastic. Rubber strain crystallizes Rubber exhibits unique physical and chemical properties. Rubber's stress- strain behavior exhibits the Mullins effect, the Payne effect and is often modeled as hyper elastic. Rubber strain crystallizes

50. Uses The use of rubber is widespread, ranging from household to industrial products, entering the production stream at the intermediate stage or as final products hoses, belts, matting, flooring, Gloves, carpet industry The use of rubber is widespread, ranging from household to industrial products, entering the production stream at the intermediate stage or as final products hoses, belts, matting, flooring, Gloves, carpet industry

51. A tree woman in Sri Lanka in the process of harvesting rubber.Sri Lanka

52. Rubber latex.

53. Latex being collected from a tapped rubber tree

54. Styrene-Butadiene (SBR) Definition : is an elastomeric copolymer consisting of styrene and butadiene. is an elastomeric copolymer consisting of styrene and butadiene. It has good abrasion resistance and good aging stability when protected by additives, and is widely used in car tires where it is blended with natural rubber. It has good abrasion resistance and good aging stability when protected by additives, and is widely used in car tires where it is blended with natural rubber. High styrene-content rubbers are hard, since the Tg (glass transition temperature) of butadiene is extremely low. High styrene-content rubbers are hard, since the Tg (glass transition temperature) of butadiene is extremely low.

55. Structure of SBR Paint Shop Pro 5

56. General properties Major application characteristics: good physical properties; excellent abrasion resistance; but sensitive to oil, and ozone; electrical properties good, but not outstanding Major application characteristics: good physical properties; excellent abrasion resistance; but sensitive to oil, and ozone; electrical properties good, but not outstanding

57. Uses The elastomer is used widely in pneumatic tires, shoe heels and soles and gaskets. It is a commodity material which competes with natural rubber. Latex (emulsion) SBR is extensively used in coated papers, being one of the most cost-effective resins to bind pigmented coatings. The elastomer is used widely in pneumatic tires, shoe heels and soles and gaskets. It is a commodity material which competes with natural rubber. Latex (emulsion) SBR is extensively used in coated papers, being one of the most cost-effective resins to bind pigmented coatings.

58. The Mullins effect is the stress-strain response in filled rubbers which typically depends on the maximum loading previously encountered. The phenomenon, named for British rubber scientist, can be idealized for many purposes as an instantaneous and irreversible softening of the stress-strain curve that occurs whenever the load increases beyond its prior all-time maximum value. At times when the load is less than a prior maximum, nonlinear elastic behavior prevails. The Mullins effect is the stress-strain response in filled rubbers which typically depends on the maximum loading previously encountered. The phenomenon, named for British rubber scientist, can be idealized for many purposes as an instantaneous and irreversible softening of the stress-strain curve that occurs whenever the load increases beyond its prior all-time maximum value. At times when the load is less than a prior maximum, nonlinear elastic behavior prevails.rubbersBritishelasticrubbersBritishelastic

59. The Payne effect is a particular feature of the stress-strain behaviour of rubber, especially rubber compounds containing fillers such as carbon black. It is named after the British rubber scientist, who made extensive studies of the effect (e.g. Payne 1962). The effect is sometimes also known as the Fletcher-Gent effect, after the authors of the first study of the phenomenon (Fletcher & Gent 1953). The effect is observed under cyclic loading conditions with small strain amplitudes, and is manifest as a dependence of the viscoelastic storage modulus on the amplitude of the applied strain. Above approximately 0.1% strain amplitude, the storage modulus decreases rapidly with increasing amplitude. At sufficiently large strain amplitudes (roughly 20%), the storage modulus approaches a lower bound. In that region where the storage modulus decreases the loss modulus shows a maximum. The Payne effect depends on the filler content of the material and vanishes for unfilled elastomers. Physically, the Payne effect can be attributed to deformation- induced changes in the material's microstructure, i.e. to breakage and recovery of weak physical bonds linking adjacent filler clusters. Since the Payne effect is essential for the frequency and amplitude-dependent dynamic stiffness and damping behaviour of rubber bushings, automotive tyres and other products, constitutive models to represent it have been developed in the past (e.g. Lion et al. 2003). Similar to the Payne effect under small deformations is the Mullins effect that is observed under large deformations. rubberfillerscarbon blackviscoelasticMullins effectrubberfillerscarbon blackviscoelasticMullins effect