Citescore values are based on citation counts in a given year e. A detailed discussion of several important step growth polymeriz ations follows in the next five chapters. Step growth polymerization p olymerization mechanism in which bifunctional or multifunctional monomers react to form first dimers, then trimers, longer oligomers and eventually long chain polymers. Simulating step growth polymerization processes using custom models or commercial software can facilitate the efficient design of polymers with highly desirable properties. Dec 04, 2014 the traditional polycondensation for polyesters and polyamides but also, more recently, click reactions, olefin metathesis, multicomponent reactions, and many others have been used for stepgrowth polymerization allowing a finetuning of chemical structure and thus also of the properties of the obtained materials. If the monomers add end to end and liberate a byproduct is called step growth polymerization. Why pdi is usually greater than 2 in real polymerization.
The number distribution a is shown for three different extents of reaction, the mass distribution b shows a single narrow peak which progressively broadens and shifts to high molecular mass as. The other process, called stepgrowth polymerization, involves the buildup of molecular weight not in a chainlike fashion but in a stepwise fashion, by the random combination of monomer molecules containing reactive functional groups. Copy of 0510 quiz 3 introduction to polymers this week we saw a demonstration of nylon synthesis, we generally discussed stepgrowth or condensation and chaingrowth or addition polymerization and went through a list of about 30 common polymers and copolymers including their chemical structure. Reaction engineering of step growth polymerization. The oldest polymers rejuvenated leen billieta, david fournierb, filip du preza, adepartment of organic chemistry, polymer chemistry research group, ghent university, krijgslaan 281 s4bis, b9000 ghent, belgium. If you want to learn how to simulate stepgrowth polymerization processes using commercial software and seek an indepth, quantitative understanding of how to develop, use, and. At that time we noted that these classifications could be based on the following. Transformation of stepgrowth polymerization into living chain. In chain growth or chain polymerization, the only chainextension reaction step is the addition of a monomer to a growing chain with an active center such as a free radical or ion. Transformation of stepgrowth polymerization into living. In contrast, chaingrowth polymerization occurs by introducing an active growth center into a monomer, followed by the addition of many monomers to that center by a chaintype kinetic mechanism.
Feature article stepgrowth polymerization and click chemistry. Merging macromolecular and supramolecular chemistry into. If you want to learn how to simulate step growth polymerization processes using commercial software and seek an indepth, quantitative understanding of how to develop, use, and deploy. Chapter three, chaingrowth polymerization, version of. Chemical engineering 160260 polymer science and engineering. All molecules present monomer, oligomer, polymer can react with any other molecule.
Flory assumed that all steps, that is, the formation of dimers, trimers and so forth, have equal rate constants. Chaingrowth polymerization, by contrast, requires at least three distinctly different kinds of reactions to describe the mechanism. It is known that chaingrowth polymerization can create a more heterogeneous network structure than stepgrowth polymerization. This assumption greatly simplifies the otherwise very complicated kinetics of a condensation polymerization. Stepgrowth polymerization refers to a type of polymerization mechanism in which bifunctional or multifunctional monomers react to form first dimers, then. A single difunctional monomer difunctional monomers may react to form polymer chains. Compared to chaingrowth polymerization, where the production of the growing chaingrowth is based on the reaction between polymer with active center and monomer, stepgrowth polymerization doesnt have initiator or termination. Many naturally occurring and some synthetic polymers are produced by stepgrowth polymerization, e. Just think of the way your bank keeps merging with other banks and getting.
Two other types of monomers that combine via stepgrowth polymerization. Many naturally and synthetic polymers are produced by stepgrowth. These unsaturated monomers the identical molecules that make up the polymers have extra internal bonds that are able to break and link up with other monomers to form a repeating chain, whose backbone typically contains. As the name suggests, step growth polymerization proceeds in a step wise fashion. This free online tool allows to combine multiple pdf or image files into a single pdf document. Here molecular weight of monomer and repeat unit is different, bi product my h 2 o, co 2, nh 3 etc. Chapter two, stepgrowth polymerization, version of 1505 76 2. Our pdf merger allows you to quickly combine multiple pdf files into one single pdf document, in just a few clicks. Apr 30, 2015 characteristics of chain growth polymerisation growth by addition of monomer only at one end or both ends of chain some monomer remains even at long reaction times different steps operate at different stages of mechanism i. Stepgrowth polymerization is the method most commonly employed, although hydrogenbonddriven polypseudorotaxane formation has also been reported from preformed polyurethane backbones in combination with 30crown10 or 42crown14 rings. To see an animated model of the radical chaingrowth polymerization of vinyl chloride. Chaingrowth polymerization or chain polymerization is a polymerization technique where. Step growth polymerization and condensation polymerization are two different concepts, not always identical. Growth polymerization process modeling and product.
Stepgrowth polymerization article about stepgrowth. Chapter two, stepgrowth polymerization, version of 1505 75 2 stepgrowth polymerization 2. Stiile colorado state university, fort collins, co 80523 as illustrated in the articles on chain polymerization, a chaingrowth polymerization is one in which each polymer chain, after being started by a free radical initiator, a cationic catalyst or an anionic catalyst, grows rapidly, producing a high molecular weight polymer. The mass distribution b shows a single narrow peak which progressively broadens and shifts to high molecular mass as. Other articles where step growth polymerization is discussed. Step growth polymerization is the method most commonly employed, although hydrogenbonddriven polypseudorotaxane formation has also been reported from preformed polyurethane backbones in combination with 30crown10 or 42crown14 rings. Reaction engineering of step growth polymerization springerlink. Stiile colorado state university, fort collins, co 80523 as illustrated in the articles on chain polymerization, a chain growth polymerization is one in which each polymer chain, after being started by a free radical initiator, a cationic catalyst or an anionic catalyst, grows rapidly, producing a high molecular weight polymer. Predicting chain length distribution in step growth.
When two or more reactive functional group reacts with each other is called condensation type polymerization. The technique is the most studied and utilized of the controlledliving radical polymerization techniques since a large number of monomers. Stepgrowth polymerization an overview sciencedirect. Long and others published stepgrowth polymerization find, read and cite all the research you need on researchgate. In fact polyurethane polymerizes with addition polymerization because its polymerization produces no small molecules, but its reaction mechanism corresponds to a step growth polymerization. Comprehensive heterocyclic chemistry iii, 2008 related terms.
Effects of the polyethylene glycol hydrogel crosslinking. Growth involves monomer units reacting with each other or with oligomers of any size. Strategic process modeling facilitates accurate prediction of the properties. Step polymerisation polymerization materials science. A living polymerization polystyrenemaybeproducedbythepolymerizationofstyrenemonomerwith an initiator. Step growth polymerization of inorganic nanoparticles article pdf available in science 3295988. Following a comparison of chain growth and step growth polymerization, focuses on the latter process by describing requirements for high molecular weight, step growth polymerization kinetics, synthesis and molecular weight distribution of some linear step growth polymers, and threedimensional network step growth polymers. The reactivity of a functional group is independent of the size of the molecule to which it is attached.
Step growth polymerization, types of monomers, kinetics and equilibrium considerations, closed vs. The other process, called step growth polymerization, involves the buildup of molecular weight not in a chainlike fashion but in a stepwise fashion, by the random combination of monomer molecules containing reactive functional groups. Here the covalent bonding occurs by an s n 2 reaction between a nucleophile, usually an amine, and a terminal epoxide. This is a stepgrowth polymerization not a chaintransfer or radical polymerization. Growth proceeds by a step wise intermolecular reaction growth involves monomer units reacting with each other or with oligomers of any size the reactivity of a functional group is independent of the size of the molecule to which it is attached the reactivity of a functional group is independent of. Putting them together polymer science learning center. These are quite general, and can easily be applied in such diverse and emerging fields as polymerization applications in photolithography and microelec tronics. The monomer in stepgrowth polymerization will be consumed very quickly to dimer, trimer or oligomer. The number distribution a is shown for three different extents of reaction. Comparison of common polymerization methods stepgrowth chaingrowth anionic growth method cons.
Predicting chain length distribution in step growth polymerization by monte carlo method wahyudi budi sediawan1, megawati2. Understand quantitative model stepgrowth polymerization plans and how to predict properties of the product polymer with the essential information in stepgrowth polymerization process modeling and product design. Once the growth of a chain is initiated by formation of an active center, chain propagation is usually rapid by addition of a sequence of monomers. Pdf stepgrowth polymerization of inorganic nanoparticles. In this classification scheme, a step growth polymerization is defined as one that involves a random reaction of two molecules that may be any combination of a monomer, oligomer, or a longerchain molecule. Made by faculty at the university of colorado boulder department of chemical and biological engineering. Figure 41 molecular mass distributions in step growth polymerization.
Nanoparticles from stepgrowth coordination polymerization. Step growth polymerization and condensation polymerization step growth polymerization and condensation polymerization are two different concepts, not always identical. Ppg industries has received a patent for a compound that is comprised of the reaction product of a highly branched polymer having terminal amine functional groups and a lactam, wherein the highly branched polymer is the stepgrowth polymerization reaction product of a polyfunctional first monomer having a first functional group and a polyfunctional second monomer having a second functional. Growth proceeds by a stepwise intermolecular reaction. Growth regulated by regulating nucleation of new barbed ends this is done by regulating the amount of active arp23. During propagation, only monomers react to the active site at the end of the growing chain.
In stepgrowth polymerizations, any species monomers, dimers, trimers, etc. Durham etheses some studies in stepgrowth photoreductive. Stepgrowth polymerization process modeling and product. Following a comparison of chaingrowth and stepgrowth polymerization, focuses on the latter process by describing requirements for high molecular weight, stepgrowth polymerization kinetics, synthesis and molecular weight distribution of some linear stepgrowth polymers, and threedimensional network stepgrowth polymers.
The functional groups on two monomers react to form a dimer, the dimer reacts with another monomer to form a trimer, and these reactions lead to many monomeric units linked to form an intermediate molecular weight material, which is known as an oligomer, and eventually a polymer. Other articles where stepgrowth polymerization is discussed. Ppg industries has received a patent for a compound that is comprised of the reaction product of a highly branched polymer having terminal amine functional groups and a lactam, wherein the highly branched polymer is the step growth polymerization reaction product of a polyfunctional first monomer having a first functional group and a polyfunctional second monomer having a second functional. Synthesis of star polymer with linear polytriazole arms from a core. The first six chapters present the principles of step growth polymerization. Bivariate distribution and related analytical solutions for batch. Stepgrowth polymerization american chemical society.
Now the differences between a chain growth polymerization and a step growth. Initiation, propagation, termination, and chain transfer molar mass of backbone chain increases rapidly at early stage. The active center is ultimately killed off by a termination. This assumption greatly simplifies the otherwise very complicated kinetics of a. Chemical engineering, faculty of engineering, semarang state universitybldg. Stepgrowth polymerization is also used for preparing a class of adhesives and amorphous solids called epoxy resins. Chemical engineering, faculty of engineering, gadjah mada university jl. Stepgrowth polymerization an overview sciencedirect topics. Combines pdf files, views them in a browser and downloads. In this classification scheme, a stepgrowth polymerization is defined as one that involves a random reaction of two molecules that may be any combination of a monomer, oligomer, or a longerchain molecule.
How to combine files into a pdf adobe acrobat dc tutorials. Jan 30, 2012 an introduction to step growth polymerization. The kinetics of the stepgrowth polymerization can be described with florys equal reactivity principle. Chapter two, step growth polymerization, version of 1505 75 2 step growth polymerization 2. Open systems kinetics of step growth polymerization chapter 2.
In this equation, p is the polymer while x represents degree of polymerization, means active center of chain growth polymerization, m is the monomer which will react with active center, l is a lowmolarmass byproduct obtained during chain propagation. Stiile colorado state university, fort collins, co 80523 as illustrated in the articles on chain polymerization, a chaingrowth polymerization is one in which each polymer chain, after being started by a free radical initiator, a cationic catalyst or an anionic catalyst, grows rapidly, producing a high. Owing to the many advantages over step growth polymerizations, chain growth polymerization has been utilized in a variety of controlled polymer synthesis, including many important industrial. In general, two classes of stepgrowth polymerization sgp reactions. Why pdi is usually greater than 2 in real polymerization system. Stepgrowth polymerization forms polymers in a manner that is quite different from chain. Polymer synthesis a s discussed in chapter 1, a useful classification of all polymers is based upon the kinetics of the polymerization. In the following example, the same bisphenol a intermediate used as a monomer for lexan serves as a. The easiest way to visualize the stepgrowth mechanism is a crowd of people reaching out. Choose from a variety of file types multiple pdf files, microsoft word documents, microsoft excel spreadsheets, microsoft powerpoint. Atom transfer radical polymerization atrp has proven to be a powerful technique to obtain polymers with narrow polydispersities and controlled molecular weight.