[Skip to Content](https://www.sigmaaldrich.com#main-content) [](https://www.sigmaaldrich.com/US/en) Products Cart0 USEN Products [Login / Register](https://www.sigmaaldrich.com/oidc-sign-in) [Order Lookup](https://www.sigmaaldrich.com/US/en/order-lookup) [Quick Order](https://www.sigmaaldrich.com/US/en/quick-order) Cart0 [Home](https://www.sigmaaldrich.com/US/en)[Applications](https://www.sigmaaldrich.com/US/en/applications)[Materials Science and Engineering](https://www.sigmaaldrich.com/US/en/applications/materials-science-and-engineering) Polymer Synthesis Techniques # Polymer Synthesis Techniques  Polymers are a class of materials comprising small repeating chemical units. The building block or the repeating unit in the polymer is called a monomer. Polymerization, or polymer synthesis, is a chemical reaction in which monomers are joined together by covalent bonding to form polymer structures. The length of the polymer chain is characterized by the number of repeating units in the chain, which is referred to as degree of polymerization (DP). The molecular weight of the polymer is the product of the molecular weight of the repeating unit and the DP. The basic properties inherent to polymers mainly depend on the molecular weight, structure (linear or branched), and DP.   * * * ## Related Products Slide 1 of 8 1 of 2 [ \ Sigma-Aldrich \ 730114 \ 2-Methacryloyloxyethyl phosphorylcholine](https://www.sigmaaldrich.com/US/en/product/aldrich/730114) Quick View [ \ Sigma-Aldrich \ 477028 \ 2-Hydroxyethyl methacrylate](https://www.sigmaaldrich.com/US/en/product/aldrich/477028) Quick View [ \ Sigma-Aldrich \ 220892 \ 1,4-Butanediol diglycidyl ether](https://www.sigmaaldrich.com/US/en/product/aldrich/220892) Quick View [ \ Sigma-Aldrich \ 723037 \ 2-Cyano-2-propyl dodecyl trithiocarbonate](https://www.sigmaaldrich.com/US/en/product/aldrich/723037) Quick View [ \ Sigma-Aldrich \ 722987 \ 2-Cyano-2-propyl benzodithioate](https://www.sigmaaldrich.com/US/en/product/aldrich/722987) Quick View [![4-Cyano-4-\[(dodecylsulfanylthiocarbonyl)sulfanyl\]pentanoic acid 97% (HPLC)](https://www.sigmaaldrich.com/deepweb/assets/sigmaaldrich/product/structures/204/925/30ae6ca0-5b0b-4963-a061-7e5e3d1a85af/640/30ae6ca0-5b0b-4963-a061-7e5e3d1a85af.png) \ Sigma-Aldrich \ 723274 \ 4-Cyano-4-\[(dodecylsulfanylthiocarbonyl)sulfanyl\]pentanoic acid](https://www.sigmaaldrich.com/US/en/product/aldrich/723274) Quick View [ \ Sigma-Aldrich \ 723150 \ 2-Hydroxyethyl 2-bromoisobutyrate](https://www.sigmaaldrich.com/US/en/product/aldrich/723150) Quick View [ \ Sigma-Aldrich \ 415952 \ Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide](https://www.sigmaaldrich.com/US/en/product/aldrich/415952) Quick View * * * ## Featured Categories [](https://www.sigmaaldrich.com/US/en/products/materials-science/biomedical-materials/polymerization-tools) [Polymerization Tools](https://www.sigmaaldrich.com/US/en/products/materials-science/biomedical-materials/polymerization-tools) We provide reliable polymerization tools to initiate and manipulate a chemical reaction of monomers to form polymer chains or networks with specific properties for diverse applications. 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[Shop Products](https://www.sigmaaldrich.com/US/en/products/materials-science/biomedical-materials/polyethylene-glycol) [](https://www.sigmaaldrich.com/US/en/products/materials-science/biomedical-materials/biomedical-polymers) [Biomedical Polymers](https://www.sigmaaldrich.com/US/en/products/materials-science/biomedical-materials/biomedical-polymers) We offer an extensive range of natural and synthetic biomedical polymers with advanced properties suitable for all your biomedical applications. [Shop Products](https://www.sigmaaldrich.com/US/en/products/materials-science/biomedical-materials/biomedical-polymers) [](https://www.sigmaaldrich.com/US/en/products/materials-science/biomedical-materials/hydrophobic-polymers) [Hydrophobic Polymers](https://www.sigmaaldrich.com/US/en/products/materials-science/biomedical-materials/hydrophobic-polymers) Explore our portfolio of versatile hydrophobic polymers to support your adhesion, coating, fiber, film, engineered plastic and biomedical applications. [Shop Products](https://www.sigmaaldrich.com/US/en/products/materials-science/biomedical-materials/hydrophobic-polymers) * * * Overview Related Articles & Protocols Support Based on the types of chemical reaction involved, polymerizations are grouped into two types, known as condensation and addition polymerization. In condensation or step-growth polymerization, a condensation reaction takes place between two different bi-functional or tri-functional monomers to produce polymers, whereby small molecules, often water, are eliminated from the reaction. In addition polymerization, or chain-growth polymerization, the growth of the polymer occurs by adding monomers to active sites on the polymer chain with regeneration of the active sites at the end of each growth step. An initiator is required to produce the initiator species with reactive centers. The reactive center can be a free radical, cation, anion, or organometallic complex. The characteristics of polymers are highly dependent on monomer types and the polymerization method used for the synthesis. Living radical polymerization, also referred to as controlled radical polymerization (CRP), enables better control over the polymer molecular weight, molecular weight distribution, functionality, and composition. CRP can be utilized with a wide range of vinyl monomers to build polymers with diverse properties for different applications. There are three fundamental CRP techniques: - Atom transfer radical polymerization (ATRP) - Reversible addition/fragmentation chain transfer (RAFT) polymerization - Nitroxide-mediated polymerization (NMP) ATRP is well-suited for surface modification applications which rely on tailored hydrophilicity, adhesive properties, or nanoparticle functionalization. Polymers derived from both RAFT and ATRP can be modified post-polymerization and are used extensively in the biomedical field for drug delivery and tissue engineering applications. Block copolymers for biomedical applications, are commonly developed from RAFT or ATRP. Block copolymers, developed from NMP, are essential for pigment dispersion, memory devices, and composite manufacturing. 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[Find Documents](https://www.sigmaaldrich.com/documents-search) ## Related Articles - [RAFT: Choosing the Right Agent to Achieve Controlled Polymerization](https://www.sigmaaldrich.com/US/en/technical-documents/technical-article/materials-science-and-engineering/polymer-synthesis/raft-polymerization) Find reversible addition–fragmentation chain transfer(RAFT) polymerization process, classes of RAFT agents & applications. - [Thermal Transitions of Homopolymers: Glass Transition & Melting Point](https://www.sigmaaldrich.com/US/en/technical-documents/technical-article/materials-science-and-engineering/polymer-synthesis/thermal-transitions-of-homopolymers) Literature values for the glass transition temperature, (Tg), and melting temperature, (Tm), are given for the more common homopolymers. - [Materials for High and Low Refractive Index Coatings](https://www.sigmaaldrich.com/US/en/technical-documents/technical-article/materials-science-and-engineering/polymer-synthesis/refractive-index-coatings) Refractive index (RI or n) is of critical importance for photonics applications such as optical waveguides and ophthalmic devices. Based on their unique refractive index characteristics and good optical clarity, polymeric materials are also used as anti-reflective coatings for solar cells, displays and contact lenses. - [MALDI-TOF Characterization of Functionalized Polymers](https://www.sigmaaldrich.com/US/en/technical-documents/technical-article/materials-science-and-engineering/polymer-synthesis/maldi-functional-polymers) MALDI-TOF MS is useful for monitoring complete conjugation.  Functionalized polymers are useful for creating polymer conjugates for diverse applications. - [ATRP Ligands & Initiators: Clean Functional Polymers](https://www.sigmaaldrich.com/US/en/technical-documents/technical-article/materials-science-and-engineering/polymer-synthesis/atrp-for-everyone) ATRP is a successful method for precise polymer synthesis with controlled molecular weights and high chain end functionalities. - [See All (45)](https://www.sigmaaldrich.com/US/en/search/facet-search?focus=sitecontent&term=facet-search) ## Related Protocols - [Polymerizing via ATRP](https://www.sigmaaldrich.com/US/en/technical-documents/protocol/materials-science-and-engineering/polymer-synthesis/typical-procedures-for-polymerizing-via-atrp) Polymerization via ATRP procedures demonstrated by Prof. Dave Haddleton's research group at the University of Warwick. - [Preparation of Monodisperse Polymer Spheres](https://www.sigmaaldrich.com/US/en/technical-documents/protocol/materials-science-and-engineering/nanoparticle-and-microparticle-synthesis/preparation-of-monodisperse-polymer-spheres) Polymeric spheres serve as crystal templates. Synthesis methods yield large quantities. - [Concepts and Tools for RAFT Polymerization](https://www.sigmaaldrich.com/US/en/technical-documents/protocol/materials-science-and-engineering/polymer-synthesis/concepts-and-tools-for-raft-polymerization) We present an article about RAFT, or Reversible Addition/Fragmentation Chain Transfer, which is a form of living radical polymerization. - [Typical Procedures for Polymerizing via RAFT](https://www.sigmaaldrich.com/US/en/technical-documents/protocol/materials-science-and-engineering/polymer-synthesis/typical-procedures-for-polymerizing-via-raft) We presents an article featuring procedures that describe polymerization of methyl methacrylate and vinyl acetate homopolymers and a block copolymer as performed by researchers at CSIRO. - [See All (5)](https://www.sigmaaldrich.com/US/en/search/facet-search?focus=sitecontent&term=facet-search) ### Find More Articles and Protocols Enter Keywords Search ## How Can We Help In case of any questions, please submit a [customer support request](https://www.sigmaaldrich.com/US/en/support/customer-support) or talk to our customer service team: Email [[email protected]](mailto:[email protected]) or call +1 (800) 244-1173 ## Additional Support - [Chromatogram Search](https://www.sigmaaldrich.com/chromatogram-search) Use the Chromatogram Search to identify unknown compounds in your sample. - [Calculators & Apps](https://www.sigmaaldrich.com/US/en/support/calculators-and-apps) Web Toolbox - science research tools and resources for analytical chemistry, life science, chemical synthesis and materials science. - [Customer Support Request](https://www.sigmaaldrich.com/US/en/support/customer-support) Customer support including help with orders, products, accounts, and website technical issues. - [FAQ](https://maestro.my.site.com/knowledgeportal/s/) Explore our Frequently Asked Questions for answers to commonly asked questions about our products and services. * * * __Featured Articles__ [RAFT Agents for Functionalized Polymers](https://www.sigmaaldrich.com/US/en/technical-documents/technical-article/materials-science-and-engineering/polymer-synthesis/raft-agents-for-functionalized-polymers) Low-cost, high-purity RAFT Agents are vital for industrial RAFT polymerization. We supply effective agents for this technology. [Free Radical Initiators](https://www.sigmaaldrich.com/US/en/technical-documents/technical-article/materials-science-and-engineering/polymer-synthesis/free-radical-initiators) Photoinitiators convert light energy into chemical energy for initiating species formation in formulations, essential for various applications. [Block copolymer synthesis using a commercially available nitroxide-mediated radical polymerization (NMP) initiator](https://www.sigmaaldrich.com/US/en/technical-documents/technical-article/materials-science-and-engineering/polymer-synthesis/block-copolymer-synthesis) Block copolymer synthesis using a commercially available nitroxide-mediated radical polymerization (NMP) initiator [Thermal Transitions of Homopolymers: Glass Transition & Melting Point](https://www.sigmaaldrich.com/US/en/technical-documents/technical-article/materials-science-and-engineering/polymer-synthesis/thermal-transitions-of-homopolymers) Literature values for the glass transition temperature, (Tg), and melting temperature, (Tm), are given for the more common homopolymers. Top __Sign In To Continue__ To continue reading please sign in or create an account. Sign In__Don't Have An Account?__Register An unknown error has occured. - English - EN - Español - ES [Learn More](https://www.sigmaaldrich.com)