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Polybutylene
Polybutylene (polybutene-1, poly(1-butene), PB-1) is a polyolefin or saturated polymer with the chemical formula (CH2CH(Et))n. Not be confused with polybutene, PB-1 is mainly used in piping. Production Polybutylene is produced by polymerisation of 1-butene using supported Ziegler–Natta catalysts. Catalysts Isotactic PB-1 is produced commercially using two types of heterogeneous Ziegler–Natta catalysts. The first type of catalyst contains two components, a solid pre-catalyst, the δ-crystalline form of TiCl3, and solution of an organoaluminum cocatalyst, such as Al(C2H5)3. The second type of pre-catalyst is supported. The active ingredient in the catalyst is TiCl4 and the support is microcrystalline MgCl2. These catalysts also contain special modifiers, organic compounds belonging to the classes of esters or ethers. The pre-catalysts are activated by combinations of organoaluminum compounds and other types of organic or organometallic modifiers. Two most important technologic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crystallization Of Polymers
Crystallization of polymers is a process associated with partial alignment of their molecular chains. These chains fold together and form ordered regions called Lamella (materials), lamellae, which compose larger spheroidal structures named Spherulite (polymer physics), spherulites. Polymers can crystallize upon cooling from melting, mechanical stretching or solvent evaporation. Crystallization affects optical, mechanical, thermal and chemical properties of the polymer. The degree of crystallinity is estimated by different analytical methods and it typically ranges between 10 and 80%, with crystallized polymers often called "semi-crystalline". The properties of semi-crystalline polymers are determined not only by the degree of crystallinity, but also by the size and orientation of the molecular chains. Crystallization mechanisms Solidification from the melt Polymers are composed of long molecular chains which form irregular, entangled coils in the melt. Some polymers retain such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1-butene
1-Butene (or 1-Butylene) is the organic compound with the formula CH3CH2CH=CH2. It is a colorless gas that is easily condensed to give a colorless liquid. It is classified as a linear alpha-olefin. It is one of the isomers of butene (butylene). It is a precursor to diverse products. Reactions Polymerization of 1-butene give polybutene, which is used to make piping for domestic plumbing. Its main application is as a comonomer in the production of certain kinds of polyethylene, such as linear low-density polyethylene (LLDPE). It has also been used as a precursor to polypropylene resins, butylene oxide, and butanone. Manufacturing 1-Butene is produced by separation from crude C4 refinery streams and by ethylene dimerization. The former affords a mixture of 1-and 2-butenes, while the latter affords only the terminal alkene. It is distilled to give a very high purity product. An estimated 12 billion kilograms were produced in 2011. See also *Butene *Dimer (chemistry) *Octene Oct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glass Transition Temperature
The glass–liquid transition, or glass transition, is the gradual and reversible transition in amorphous materials (or in amorphous regions within semicrystalline materials) from a hard and relatively brittle "glassy" state into a viscous or rubbery state as the temperature is increased. ISO 11357-2: Plastics – Differential scanning calorimetry – Part 2: Determination of glass transition temperature (1999). An amorphous solid that exhibits a glass transition is called a glass. The reverse transition, achieved by supercooling a viscous liquid into the glass state, is called vitrification. The glass-transition temperature ''T''g of a material characterizes the range of temperatures over which this glass transition occurs (as an experimental definition, typically marked as 100 s of relaxation time). It is always lower than the melting temperature, ''T''m, of the crystalline state of the material, if one exists. Hard plastics like polystyrene and poly(methyl methacrylate) are u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tensile Stress
In continuum mechanics, stress is a physical quantity. It is a quantity that describes the magnitude of forces that cause deformation. Stress is defined as ''force per unit area''. When an object is pulled apart by a force it will cause elongation which is also known as deformation, like the stretching of an elastic band, it is called tensile stress. But, when the forces result in the compression of an object, it is called compressive stress. It results when forces like tension or compression act on a body. The greater this force and the smaller the cross-sectional area of the body on which it acts, the greater the stress. Therefore, stress is measured in newton per square meter (N/m2) or pascal (Pa). Stress expresses the internal forces that neighbouring particles of a continuous material exert on each other, while strain is the measure of the deformation of the material. For example, when a solid vertical bar is supporting an overhead weight, each particle in the bar pushes o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chloramine
Chloramines refer to derivatives of ammonia and organic amines wherein one or more N-H bonds have been replaced by N-Cl bonds. Two classes of compounds are considered: inorganic chloramines and organic chloramines. Inorganic chloramines Inorganic chloramines comprise three compounds: monochloramine (NH2Cl), dichloramine (NHCl2), and nitrogen trichloride (NCl3). Monochloramine is of broad significance as a disinfectant for water. Organic chloramines 144px, ''N''-Chloropiperidine is a rare example of an organic chloramine. 144px, Chloramine-T is often referred to as a chloramine, but it is really a salt (CH3C6H4SO2NClNa) derived from a chloramine. Organic chloramines feature the NCl functional group attached to an organic substituent. Examples include ''N''-chloromorpholine (ClN(CH2CH2)2O), ''N''-chloropiperidine, and ''N''-chloroquinuclidinium chloride. Chloramines are commonly produced by the action of bleach on secondary amines: :R2NH + NaOCl → R2NCl + NaOH ''Te ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chlorine
Chlorine is a chemical element with the Symbol (chemistry), symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate between them. Chlorine is a yellow-green gas at room temperature. It is an extremely reactive element and a strong oxidising agent: among the elements, it has the highest electron affinity and the third-highest electronegativity on the revised Electronegativity#Pauling electronegativity, Pauling scale, behind only oxygen and fluorine. Chlorine played an important role in the experiments conducted by medieval Alchemy, alchemists, which commonly involved the heating of chloride Salt (chemistry), salts like ammonium chloride (sal ammoniac) and sodium chloride (common salt), producing various chemical substances containing chlorine such as hydrogen chloride, mercury(II) chloride (corrosive sublimate), and hydrochloric acid (in the form of ). However ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Baltimore Sun
''The Baltimore Sun'' is the largest general-circulation daily newspaper based in the U.S. state of Maryland and provides coverage of local and regional news, events, issues, people, and industries. Founded in 1837, it is currently owned by Tribune Publishing. The ''Baltimore Sun's'' parent company, '' Tribune Publishing'', was acquired by Alden Global Capital, which operates its media properties through Digital First Media, in May 2021. History ''The Sun'' was founded on May 17, 1837, by printer/editor/publisher/owner Arunah Shepherdson Abell (often listed as "A. S. Abell") and two associates, William Moseley Swain, and Azariah H. Simmons, recently from Philadelphia, where they had started and published the '' Public Ledger'' the year before. Abell was born in Rhode Island, became a journalist with the ''Providence Patriot'' and later worked with newspapers in New York City and Boston.Van Doren, Charles and Robert McKendry, ed., ''Webster's American Biographies''. (Springfiel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cox V
Cox may refer to: * Cox (surname), including people with the name Companies * Cox Enterprises, a media and communications company ** Cox Communications, cable provider ** Cox Media Group, a company that owns television and radio stations ** Cox Automotive, an Atlanta-based business unit of Cox Enterprises * Cox Models, aka Cox Hobbies * Cox Sports, a regional sports network that served the United States New England region until 2012 Places Antarctica * Cox Glacier * Cox Nunatak * Cox Peaks * Cox Point * Cox Reef United States * Cox, Florida * Cox, Missouri * Cox College (Georgia), a defunct private women's college located in College Park, Georgia * Cox College (Missouri), a private college in Springfield, Missouri * Cox Furniture Store, c. 1890, a historic site in Gainesville, Florida * Cox Furniture Warehouse, a historic site in Gainesville, Florida * Cox Run, a tributary of Little Muncy Creek in Lycoming County, Pennsylvania * Cox site Elsewhere * Cox Island ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Class Action Lawsuit
A class action, also known as a class-action lawsuit, class suit, or representative action, is a type of lawsuit where one of the parties is a group of people who are represented collectively by a member or members of that group. The class action originated in the United States and is still predominantly a US phenomenon, but Canada, as well as several European countries with civil law, have made changes in recent years to allow consumer organizations to bring claims on behalf of consumers. Description In a typical class action, a plaintiff sues a defendant or a number of defendants on behalf of a group, or class, of absent parties. This differs from a traditional lawsuit, where one party sues another party, and all of the parties are present in court. Although standards differ between states and countries, class actions are most common where the allegations usually involve at least 40 people who the same defendant has injured in the same way. Instead of each damaged person bring ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Masterbatch
Masterbatch (MB) is a solid additive used for coloring (color masterbatch) or imparting other properties (additive masterbatch) to plastics. Masterbatch is a concentrated mixture of pigments and/or additives which is manufactured by encapsulation during a heat process or twin screw extrusion into a carrier matrixresin, which is then cooled and further cut into a granular shape. Masterbatch allows the processor to color raw polymer economically. The alternatives to using masterbatches are buying a fully compounded material (which may be more expensive and less open to e.g. color variability of the product), or compounding from raw materials on site (which is prone to issues with achieving full dispersion of the colorants and additives, and prone to preparing more material than what is used for the production run). In comparison with pure pigments, masterbatches require more storage space and their lead times are longer. Another disadvantage is additional exposure of heat ("heat histo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flame Retardant
The term flame retardants subsumes a diverse group of chemicals that are added to manufactured materials, such as plastics and textiles, and surface finishes and coatings. Flame retardants are activated by the presence of an ignition source and are intended to prevent or slow the further development of ignition by a variety of different physical and chemical methods. They may be added as a copolymer during the polymerisation process, or later added to the polymer at a moulding or extrusion process or (particularly for textiles) applied as a topical finish. Mineral flame retardants are typically additive while organohalogen and organophosphorus compounds can be either reactive or additive. Classes Both Reactive and Additive Flame retardants types, can be further separated into four distinct classes: * Minerals such as aluminium hydroxide (ATH), magnesium hydroxide (MDH), huntite and hydromagnesite, various hydrates, red phosphorus, and boron compounds, mostly borates. * Organ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Filler (materials)
Filler materials are particles added to resin or binders (plastics, composites, concrete) that can improve specific properties, make the product cheaper, or a mixture of both. The two largest segments for filler material use is elastomers and plastics. Worldwide, more than 53 million tons of fillers (with a total sum of approximately US$18 billion) are used every year in application areas such as paper, plastics, rubber, paints, coatings, adhesives, and sealants. As such, fillers, produced by more than 700 companies, rank among the world's major raw materials and are contained in a variety of goods for daily consumer needs. The top filler materials used are ground calcium carbonate (GCC), precipitated calcium carbonate (PCC), kaolin, talc, and carbon black. Filler materials can affect the tensile strength, toughness, heat resistance, color, clarity etc. A good example of this is the addition of talc to polypropylene. Most of the filler materials used in plastics are mineral or glas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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