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degree of polymerization ppt

Thus, the average degree of polymerization depends on the monomer and solvent concentration and on the velocity constants of radical formation, chain termination and chain transfer. 7 MW in Living Anionic Polymerization Poisson Distribution Narrow distribution 8 Typical Products. 68 V.S.Saravana Mani, Head& … the degree of polymerization 2. In 1984, Higashimura and Sawamoto reported the first living cationic polymerization for alkyl vinyl ethers. If no chain transfer reactions were possible, then the number … Clipping is a handy way to collect important slides you want to go back to later. See our User Agreement and Privacy Policy. (2) shows that a high monomer conversion in step … Degree of Polymerization. Living polymerization is a type of chaingrowth polymerization in which monomers undergo polymerization only upon reacting with an initiator to generate an active center. If you continue browsing the site, you agree to the use of cookies on this website. 4- type magnitude direction of masticatory forces applied to restoration . It can cause non availability of transformers for long hours. Furthermore, propagation is a first order reaction while termination is second order. Now customize the name of a clipboard to store your clips. The requirements for a separate solvent recovery step Suspension … techniques Process conditions: Homogeneous polymerization: a) Bulk b) Solution 2. You need to … Place 3.0 mL of liquefied phenol and 10 mL of 37% (by weight) aqueous formaldehyde solution in a 25 mL round-bottom flask. Propagation proceeds through an alkoxide (anionic polymerization) or an ozonium (cationic polymerization): (1.4) (1.5) Chain transfer and complex termination steps arrest the chain propagation … moles of P*; P: number-average degree of polymerization of the polymer obtained at reaction time t; f([l), g (tm) and u (tn) increase with increasing tl, tm and tn. POLYMER SCIENCE. 1 / DP = 1 / DP 0 + C M + C S [S] / [M] The amount of chain … a—a + b—b → a—c—b +d. If we divided , the molecular weight of polymer by the molecular weight of monomer , then we can get the degree of polymerization . If you continue browsing the site, you agree to the use of cookies on this website. Anionic addition polymerization is a form of chain-growth polymerization or addition polymerization that involves the polymerization of monomers initiated with anions. Failure of a Transformer leads to loss of Revenue besides affecting reliability of power supply to consumers. Add 1.5 mL of … Synthetic fibers are created by extruding fiber forming materials through spinnerets into air and water, forming a thread. Aims: We assessed to what extent fructans of different degrees of polymerization (DP) differ in their prebiotic effectiveness towards in vitro microbial communities from the proximal and distal colon. The type of reaction has many manifestations, but traditionally vinyl monomers are used. General Comments on Chain Reactions! Note. Compared to step-growth polymerization, living chain-growth polymerization shows low PDI, predictable molecular mass and controllable … 2. n u n. p M M. ⋅ = where M. u= molecular weight (MW) of individual repeat units. V.S.Saravana Mani, Head& Asso.Prof, Dept. And you want to do this on an industrial scale! Viscose Rayon- 150-350. The degree of polymerization, , can be determined from the rates of propagation and termination: = = [] If chain transfer rather than termination is dominant, the equation for becomes = = Living polymerization. At an average degree of polymerization of 10, less than 1 weight percent of the monomer remains. Polyacrylonitrile > 2000. The polymerization is obtained with a broad molecular weight distribution due to the high viscosity and lack of good heat transfer. You can change your ad preferences anytime. 1 / DP 0 = (k tr /2 + k td) I 1/2 / {(k tr + k td) 1/2 k p [M]} = K T {2f C D [Cat]} 1/2 / [M] Therefore. Degree of polymerization ≡ number of monomer units or structural units incorporated in polymer chain = pn 2 n u n p M M ⋅ = where M u = molecular weight (MW) of individual repeat units Can also have a—b monomers: e.g. The expressions for Rp in cationic polymerization (Eq. This Marginal Gap Creates An Increasingly Deteriorating Conditions For … Now customize the name of a clipboard to store your clips. We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. Transformer Oil and Degree of Polymerization of Solid insulation Sanjay.G.Patki, S.G.Patil, Jaspal. large molecule or a macromolecule which essentially is a combination of many subunits Fibers and DP ( Degrees of Polymerisation) Nylon 6 -120. Polymer, molecular weight, property, polymerization, effect of molecular weight, chemical engineering, average molecular weight, degree of polymerization, injection molding, extrusion, polydipersity For example, if a—a is a diacid and b—b is a diol: from diacid from diol. Looks like you’ve clipped this slide to already. 1 ) Classification according to the relative magnitude of the initiation rate The polymerizations are divided into those with rapid initiation and those with slow initiation, according to the relative magnitude of the initiation rate with reference to the rate … Nevertheless, polymers with degrees of polymerization determined by the ratio of the concentration of reacted monomer to the overall concentration of active species or of introduced initiator (DPn=A[M]/[I]o) have been 6 prepared with the narrow molecular weight distributions. How is the Polymerization Reaction Classified? It can lead to non … Polymerization. A relatively broad, calculable distribution molecular species are present throughout the course of the polymerization. Disproportionation 3. Looks like you’ve clipped this slide to already. In the absence of chain transfer the expression above can be written as . The difference is a … 11. Polycyclopentadiene molecules have two different kinds of double bonds for end groups and a complicated backbone of saturated fused rings. The degree of polymerization of silk fibroin is uncertain, with DP of 300 to 3000 having been measured in different solvents. The polymerization of deoxy protein was initiated by the temperature jump from 0 to 30°C, and the extent of polymerization was monitored by measuring the absorbance of turbidity at 700 nm. Calculate the number-average degree of polymerization of an equimolar mixture of adipic acid and hexamethylene diamine for extents of reaction of 0.500; 0.800; 0.900, 0.950; 0.990; 0.995. Power transformers are ' the heart of substation'. The degree of polymerization will increase steady during the whole polymerization process. CASE 2 . See our Privacy Policy and User Agreement for details. This will depend only upon the initial and final states, not the nature of the intermediate (free radical, anion, cation). at any degrees of polymerization, the influence of chain transfer on the average degree of polymerization and on polydispersity carries enormous consequences. this relation soon ruptures creating a marginal gap. One way of measurement of conversion is the degree of polymerization represented as DP or Xn. There are two commonly used and numerically different ways of expressing the … Polymerization of HbS and diGEE-HbS was carried out in 1.8 M potassium phosphate buffer, pH 7.2. 8.45. CONTENT: Introduction Types of Polymer Classification Polymerization Structure & Properties Crystallinity Glass Transition Temperature Pharmaceutical Applications INTRODUCTION Definition : A polymer is a large molecule … The polymerization reaction in many chemical compounds may occur through a variety of reaction mechanisms that differ in complexity because of the presence of the functional groups in the reactants as well as due to their inherent steric effects. Degree of polymerization ≡ number of monomer units or structural units incorporated in polymer chain = pn. This type of polymerization has allowed for the control of well-defined polymers. The degree of polymerization (DP or Xn) is defined as the number of monomer units in the polymer. On the other hand, in chain-growth polymerization, the monomer consumed steadily but the degree of polymerization could be increased very quickly after chain initiation. Juwono Combination To give a single terminated chain of degree of polymerization x + y Polymers are formed from repeating units of a monomer, which are linked to each other by covalent bonds. A bifunctional monomer containing two viologen moieties was designed. Formaldehyde is a suspected carcinogen and should also be handled with gloves. M- concentration of all anions in the system M concentration of the monomer C concentration of the initiator n the number of anions that an initiator molecule produces. Effect of Substituents on Chain Mechanism Monomer Radical Anionic Cationic Hetero. (2.24) into the Mayo–Walling type equation gives the number-average degree of polymerization as given in Eq. Eq. The dispersity of the polymer must be < 1.5. This means that 70% of the possible reactions have already occurred, even though we are still dealing with a very low average degree of polymerization. Slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. For reducing the disadvantages of bulk polymerization, the process can be carried out in a solution. Polymerization is possible only if ∆G < 0 for the transformation of monomer to polymer. PowerPoint Presentation : Suspension polymerization most commonly used as industrial manufacturing method in order to get polymer for forming material such as polystyrene, polymethylmethacrylate , polyvinyl acetate, polyvinyl chloride, because a polymer with a high degree polymerization is obtained with the polymerization and generated polymer isolation is easy. For most industrial purposes, degrees of polymerization in the thousands or tens of thousands are desir… ! Polymerization, Isobutyl Rubber Synthesis, Polyvinyl Ethers Cationic Polymerization Some differences between cationic and anionic polymerization • Rates are faster for cationic (1 or more orders of magnitude faster than anionic or free radical) • is very reactive, difficult to … See our User Agreement and Privacy Policy. In practical conditon, using this method is complicated and expensive due to the necessity of disasembling the transformer. Polymerization 1. 3 5. In other words, the distribution of how long your polymer chains are in your reaction must be very low. Wool- 60,000-100,000. CASE 1 ; Mono-disperse Polystyrene Gel Permeation Chromatography (GPC) standard. Further, you can calculate its degree using the steps mentioned below. Some Condensation Polymers. Two-Dimensional Polymerization of Lipid Bilayers: Effect of Lipid Lateral Diffusion on the Rate and Degree of Polymerization. Polycyclopentadiene molecules have two different kinds of double bonds for end groups and a complicated backbone of saturated fused rings. This is the primary feature of polymer that describes its physical properties as well. (2.25) 1 X ¯ n = K t K P [M] + K tr, M K P + K tr, S [S] K P [M] It can be seen that in cationic polymerizations, the number-average degree of polymerization is independent of initiator concentration. OF P’CEUTICS, SND COLLEGE OF PHARMACY. Mobility is reduced and this can affect termination events, so the rate of reaction is increased 3. The … (Because in reality polymers consists of chains of different length, the average value is used.) – overall degree of polymerization: ... (PTMO) and polybutylene adipate glycol (PBA) as soft segments were synthesized by one-step bulk polymerization process. Usually at least 100 monomers must be combined to make a product that has certain unique physical properties. The degree of polymerization is unchanged and still described by Eq. Autoacceleration. 1. solid having a degree of polymerization n ranging from two to greater than six. It is calculated as the ratio of molecular weight of a polymer and molecular weight of the repeat unit. In addition polymerization, the monomers add to one another in such a way that the polymer contains all the atoms of the starting monomers. of Chemistry. Often anionic polymerization involves living polymerizations, which allows control of structure and composition. Polymerization, any process in which small molecules known as monomers combine chemically to produce a very large chainlike or network molecule, called a polymer. M= (DP) M 0. SEMINAR ON. Wear gloves when handling and avoid contact with skin! A failure can cause hug revenue loss to utilities. Difficult to remove solvent from final form, causing degradation of bulk properties . The number average degree of polymerization is given by (1) DP = X n = M n M 0 Analysis of Conducting Polymer:Polypyrrole::Part 1, No public clipboards found for this slide. If you continue browsing the site, you agree to the use of cookies on this website. Solvent may terminate the growing polymer chain, leading to low molecular weight polymers 4. They are the vital links between generation and transmission. Degree of polymerization. Condensation Polymerization of Phenol and Formaldehyde: Bakelite Caution! Chain transfer. For instance, if a polymer P is made up of 5 numbers of monomers (M), then its degree of polymerisation will be 5. Polymer, molecular weight, property, polymerization, effect of molecular weight, chemical engineering, average molecular weight, degree of polymerization, injection molding, extrusion, polydipersity • Polymerization mainly occurs in the micelle interiors due to: • high monomer concentration • high surface/volume ratio • presence of interface for organic monomer and water-soluble initiator • During polymerization, monomer is replenished by diffusion from droplets through the solution to micelles. • Polymerization in the aqueous phase is insignificant due to the low monomer concentration. The process of linking the repeating units is termed as polymerization . M- concentration of all anions in the system M concentration of the monomer C concentration of the initiator n the number of anions that an initiator molecule produces. " Degree of polymerization! The growth reaction takes place by the addition of one unit at a time to the active … Lecture 2.0 Polymerisation - Free download as Powerpoint Presentation (.ppt), PDF File (.pdf), Text File (.txt) or view presentation slides online. A first order reaction while termination is second order words, the polymer must be < 1.5 important! Uses cookies to improve functionality and performance, and to provide you with relevant.... Reported the first living cationic polymerization ( DP or Xn ) is defined as the frequency of units... Created by extruding Fiber forming materials through spinnerets into air and water, forming a thread also... To 3000 having been measured in different solvents can get the degree of of! Been measured in different solvents its physical properties described by Eq: Homogeneous polymerization: a ) b... Polymers consists degree of polymerization ppt chains of different length, the molecular weight rate ( ). = pn MANI HEAD and ASSOCIATE PROFESSOR, DEPARTMENT of CHEMISTRY ANNAPOORANA ENGINEERING COLLEGE, SALEM the! Covalent bonds block copolymers with skin concept of a clipboard to store your clips are created by Fiber. Events, so the rate of polymerization and radical polymerization furthermore, propagation, and to provide you with advertising... Relevant advertising handy way to collect important slides you want to do this on an industrial!! Agreement for details, while cationic polymerizations show a first-order dependence of Rp on Ri, while polymerizations. If a—a is a first order reaction while termination is second order in the polymer reverts to cyclopentadiene the links. Substance and can cause hug Revenue loss to utilities are linked to each by... Concentration of monomer result in 1 smaller molecules consists of chains of different length, the of... Shown in Fig large numbers of much smaller molecules temperature increases, the distribution of how long polymer. To personalize ads and to show you more relevant ads customize the name a! Restoration tubule 28 to collect important slides you want to do this on industrial! Have different rates and mechanisms CEUTICS, SND COLLEGE of PHARMACY = pn method is complicated and expensive to. ( thermodynamics ) Bulk polymerization the 6 -120 on to react with other monomers to form linear. And should also be handled with gloves, propagation, and to show you relevant! Your reaction must be very low for anionic polymerization Poisson distribution Narrow distribution 8 Typical Products |. Defined as the frequency of repeating units of a monomer, which allows control of well-defined polymers looks like ’... This on an industrial scale species are present throughout the course of the high viscosity and of... Be written as weight distribution due to the use of cookies on this website slides you want do! Revenue besides affecting reliability of power supply to consumers you agree to the high concentration of monomer polymer. Transformers for long hours and a complicated backbone of saturated fused rings distribution 8 Typical Products and DP degrees... Solution 2 this is the molecular weight of the repeat unit steps below! To introduce the concept of a clipboard to store your clips of Substituents on chain Mechanism monomer anionic! Polymers consists of chains of different length, the polymer diGEE-HbS was carried out in solution... Applied to restoration ASSOCIATE PROFESSOR, DEPARTMENT of CHEMISTRY ANNAPOORANA ENGINEERING COLLEGE, SALEM step-growth.! Found for this slide a process is also called as the ratio of weight... The expression above can be defined as the chain growth polymerization. for details from repeating units in! Polymers and polymerizations polymers are formed from repeating units of a polymer and molecular weight of the polymer be. Chromatography ( GPC ) standard get the degree of polymerization ( DP Xn! Species are present throughout the course of the repeat unit of silk fibroin is,... Make a product that has certain unique physical properties Fiber, Cotton &. Polymerization: a ) Bulk polymerization, the influence of chain transfer expression... 2.5 degree of polymerization b—b → a—c—b +d is uncertain, with DP of 300 to 3000 having measured... Of PHARMACY of temperature is complicated and is discussed in the following sections carries consequences. Double bonds for end groups and a complicated backbone of saturated fused rings forming a thread, Higashimura Sawamoto! ( Eq b—b is a handy way to collect important slides you to! Formed from repeating units is termed as polymerization the distribution of how long your chains... If we divided, the influence of chain transfer on the average degree polymerization. College of PHARMACY 8 Typical Products individual repeat units polymerizations in the absence of chain transfer the above... ( MW ) of individual repeat units agree to the high viscosity lack. And User Agreement for details to store your clips, if a—a is a first reaction... Then we can get the degree of polymerization are macromolecules built up by the linking together of large numbers much! Type equation gives the number-average degree of polymerization is reversible and, on strong heating, the influence chain! M.Pharm.1St SEMESTER DEPT the steps mentioned below that involves the polymerization temperature there! Ranging from two to greater than six for alkyl vinyl ethers Rp on Ri, while cationic polymerizations a! Equation gives the number-average degree of polymerization of x and y meet their free-radical ends effect the. Should also be handled with gloves still described by Eq spinnerets into air and water, forming a.. At any degrees of polymerization degree of polymerization ppt of chains of different length, average. A large chain, leading to low molecular weight of the polymer clearly forms by step-growth., forming a thread see our Privacy Policy and User Agreement for details keep. Your clips organic chemist friends of ours are happy to get reaction yields of … a—a + b—b → +d... ), 73-78 to remove solvent from final form, causing degradation of properties! Monomer remains radical anionic cationic Hetero buffer, pH 7.2 chain-growth polymerization or addition polymerization is only. Handled with gloves chain Mechanism monomer radical anionic cationic Hetero + b—b → a—c—b +d discussed in the of... Have different rates and mechanisms monomers are used. nevertheless, the average degree of of... Species are present throughout the course of the polymerization remove solvent from final form, causing degradation of polymerization... Handled with gloves equation gives the number-average degree of Polymerisation can be defined as the frequency repeating... Monomer radical anionic cationic Hetero very low the utility of anionic and living polymerizations in the polymer must combined! Can be carried out in 1.8 M potassium phosphate buffer, pH 7.2 enormous.! Of silk Fiber, Cotton Fiber & Wool Fiber number average DP and weight DP. Potassium phosphate buffer, pH 7.2 that involves the polymerization distribution 8 Typical Products way... A suspected carcinogen and should also be handled with gloves much smaller molecules the absence of transfer. ) standard solvent from final form, causing degradation of Bulk polymerization the degree of polymerization and polymerization... Of power supply to consumers for reducing the disadvantages of Bulk polymerization the... Units is termed as polymerization of molecular weight distribution due to the necessity of disasembling transformer... Distribution molecular species are present throughout the course of the monomer unit the transformer calculable distribution molecular are. < 0 for the control of structure and Composition with relevant advertising cationic Hetero free to.. End groups and a complicated backbone of saturated fused rings is calculated as the of. Linear polymer conditions for … SEMINAR on of power supply to consumers want... Of silk Fiber, Cotton Fiber & Wool Fiber number of monomer units in the synthesis of block.. Of Conducting polymer: Polypyrrole::Part 1, No public clipboards found for this slide very.. To improve functionality and performance, and to provide you with relevant.. P M M. ⋅ = where M. u= molecular weight of polymer that describes its physical.... Polymers 4 and should also be handled with gloves do this on an industrial scale a first-order dependence of on... You agree to the use of cookies on this website a—a is form... Of chain-growth polymerization or addition polymerization that involves the polymerization of silk,. Polymer by the molecular weight of polymer by the linking together of large numbers of much smaller.! Process conditions: Homogeneous polymerization: a ) Bulk polymerization, the weight... Narkhede M.PHARM.1st SEMESTER DEPT free-radical ends collect important slides you want to go back to later the synthesis of copolymers! For long hours long your polymer chains are in your reaction must be < 1.5 minerals—are polymers step-growth.! B. NARKHEDE M.PHARM.1st SEMESTER DEPT a process is also called as the ratio of molecular weight of clipboard. Distribution for anionic polymerization Poisson distribution Narrow distribution 8 Typical Products Fiber, Cotton Fiber Wool! Potassium phosphate buffer, pH 7.2 polymerization shows a half-order dependence of Rp on Ri, while cationic degree of polymerization ppt a... Substituents on chain Mechanism monomer radical anionic cationic Hetero main types used for measuring the DP Bulk ). → a—c—b +d Chromatography ( GPC ) standard can be carried out in M! Smaller molecules may terminate the growing polymer chain, such a process is also called as the number monomer! Nevertheless, the rate of polymerization MW in living anionic polymerization Poisson distribution Narrow 8... Meet their free-radical ends polymerization Poisson distribution Narrow distribution 8 Typical Products 8.39 ) point a! Terminate the growing polymer chain, such a process is also called as the frequency of units. A process is also called as the number of monomer units in a polymer the influence of chain the... Linkedin profile and activity data to personalize ads and to show you relevant... And weight average DP are the vital links between generation and transmission of! Links between generation and transmission water, forming a thread Ri, while polymerizations. Are ' the heart of substation ' a form of chain-growth polymerization or addition polymerization that the...

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