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Best Polymer Resource: Polymers and Polymerization
Welcome to Polymer-Search
Polymer-Search is a one-stop resource for finding the information you need on various aspects within the polymer industry. Here you will find resources related to plastic and rubber products, as well as other polymers, such as PCV, fiberglass, and teflon. The subjects that are included in this directory include polymer products and applications, polymer manufacturing, processing and machinery, environmental health and legislation, polymer properties, analysis and testing, polymer materials and general directories and references. In addition to being a comprehensive directory on the polymer industry, visitors can also benefit from the wealth of information on products that are used on a daily basis; polymers touch every aspect of our lives.
What Is a Polymer?
A polymer is a molecule that is composed of a series of structural units that repeat themselves. Typically, these subunits have covalent chemical bonds as their connectors. The term, polymers, is more than just a reference to plastics. It includes a wide variety of synthetic and natural materials, each having an extensive amount of variation in the properties they hold. Polymers play an important role in everyday life, because of this wide variation of polymeric material properties and its versatile nature.
Some of the uses for these variations in everyday life include elastomers and familiar synthetic plastics to proteins and nucleic acids, which are natural biopolymers. Some of the natural variations of polymer materials have been used for hundreds of years; these include natural rubber, amber and shellac. Cellulose is another natural polymer, which is wood and paper’s main constituent. Some of the many synthetic polymers that exist include nylon, synthetic rubber, silicone, PVB, polyethylene, Bakelite, PVC, polypropylene, polystyrene, neoprene and polyacrylonitrile.
Carbon atoms are the most common and continuously used backbone of a polymer when preparing plastics. Polyethylene is an example that uses ethylene monomer as its base for the repeating unit. Other structures that exist include familiar materials, such as silicones, that are formed by the element silicon. Some examples of silicones include waterproof plumbing sealant and silly putty. Another common present element of polymers is oxygen; it is present in DNA, polysaccharides and polyethylene glycol.
Polymerization is a process that occurs through various reaction mechanisms in a variety of complexities, because of functional groups that are present when compounds react and the effects of those reactions as described in the VSEPR Theory. In instances in which polymerization is more straightforward, alkenes form polymers through radical reactions that are relatively simple. Alkenes are considered relatively stable, because of the bonding that occurs between carbon atoms. Due to the way reacting molecules polymerize, more complex reactions require a more complex synthesis, such as the ones that have to do with carbonyl group substitution.
Alkenes form useful compounds such as polyvinyl chloride and polyethylene when they undergo radical reactions. These compounds are produced in high amounts annually because of their usefulness in commercial products’ manufacturing processes such as packaging, insulation and piping. Polyvinyl chloride, or PVC, and other polymers like it, are typically referred to as homopolymers, because they use the same monomer unit when the repeat long structures or chains. Those types of polymers that consist of multiple molecules are called co-polymers.
Simple aldehydes or formaldehyde hydrates are other monomers that are able to form trimers in low temperatures which are considered greater than negative 80-degrees-Celsius. Trimers are molecules with three monomer units that can further react to form tetramers and can cyclize in order to form ring cyclic structures. Tetramers are compounds with four monomer units. Polymerization can be very hazardous if it proceeds at a fast rate and is not moderated sufficiently. It is a term called hazardous polymerization and is a condition that can result in explosions and fires.
One type of polymerization is step-growth polymerization. This is simply when polymers are formed by the reaction between functional groups of monomers. Although not all step-growth polymers release condensates, most are generally classified as condensation polymers. The molecular weight of these types of polymers is increased at lower conversions and an extremely low rate—they only reach the higher molecular weights when they have high conversions, such as one that is greater than 95%. In an effort to lessen the amount of inconsistencies that frequently go along with these naming methods, there have been some modifications to the definitions for addition polymers and condensation that have been developed. Condensation polymers are defined as those that involve small molecule elimination during the synthesis process, or as a part of their backbone chain contains functional groups, or all of the atoms are not present in their repeat units to be degraded in hypothetical monomers.
Chain-growth polymerization is also referred to as addition polymerization. It involves linking molecules together that incorporate double chemical bonds or triple chemical bonds. These are unsaturated monomers that have extra bonds internally which have the ability to break and link up to form a repeating chain with other monomers. This type of polymerization is involved in manufacturing polymers, such as polyvinyl chloride, polypropylene and polyethylene. Living polymerization is caused by a special situation dealing with chain-growth polymerization.
The free-radical mechanism was one of the methods in the beginning used to initiate the creation of a new propagating center. Free radicals are defined as extremely active molecules or atoms that have electrons without pairs. The free radical mechanism, when discussing ethylene’s polymerization, can be split into three separate stages: first, there is chain initiation, then followed by chain propagation and ending with chain termination. Anionic addition polymerization and cationic addition polymerization are two other types of chain growth polymerization. Anionic and Cationic mechanisms allow some monomers to polymerize, which cannot be polymerized due to factors including a lack of oxygen and water.
- The Macrogalleria: Educational and interactive resource for learning about polymers.
- Application Notes: A link to a comprehensive list of notes on testing techniques and applications that have been performed by the Cambridge Polymer Group.
- Introduction to Polymers: Online course at The Open University that provides you with a comprehensive lesson and overview on polymers and the properties of polymers.
- Guide to Polymer Abbreviations: A link to an extensive list of abbreviations used for polymers and subjects related to polymers.
- Reference: Glossary: A link to a four-page PDF document with a list of common terms used in the discussion of polymers and their meanings.
- Polymerization: Brief entry into the encyclopedia on information on what polymerization is and about the polymerization process.
- Olefin Metathesis Polymerization: Detailed information, with diagrams, on a type of polymerization called olefin metathesis polymerization.
- Polymers and Polymerization: Outline and additional information, including a video, formulas and diagrams, on polymers and the polymerization process.
- Polymerization: Comprehensive and detailed seven-page PDF document on polymerization that gives information and provides space for notes and interactive studying.
- The Polymerization Motor: Extensive 10-page PDF document that gives a detailed overview and review of the polymerization motor.
- Frontal Polymerization: Links to a document that discusses the recent advances in this aspect of chemistry and gives some examples.
- Polymerization, Polymers and Plastics: Comprehensive, 31-page PDF document that gives an in-depth look into the introduction of polymers as a workshop.
- Polymerization: Informational article that explains the polymerization process.
- Polymer Synthesis: Article that discusses addition polymerization and the statistical analysis of polymers.
- Polymers: Introduction to polymers and how to write formulas for polymers.