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Trimethylolpropane Triacrylate
Trimethylolpropane triacrylate (TMPTA) is a trifunctional acrylate ester monomer derived from trimethylolpropane, used in the manufacture of plastics, adhesives, acrylic glue, anaerobic sealants, and ink. It is useful for its low volatility and fast cure response. It has the properties of weather, chemical and water resistance, as well as good abrasion resistance. End products include alkyd coatings, compact discs, hardwood floors, concrete polymers, Dental composites, photolithography, letterpress, screen printing, elastomers, automobile headlamps, acrylics and plastic components for the medical industry. Other uses As the molecule has acrylic functionality, it is capable of doing the Michael reaction with an amine. This allows its use in epoxy chemistry where its use speeds up the cure time considerably See also *Pentaerythritol tetraacrylate * 1,6-Hexanediol diacrylate References {{reflistTRIMETHYLOLPROPANE TRIACRYLATEat chemicalland21.comat OSHA OSHA or Osha may refer to: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monomer
In chemistry, a monomer ( ; ''mono-'', "one" + '' -mer'', "part") is a molecule that can react together with other monomer molecules to form a larger polymer chain or three-dimensional network in a process called polymerization. Classification Monomers can be classified in many ways. They can be subdivided into two broad classes, depending on the kind of the polymer that they form. Monomers that participate in condensation polymerization have a different stoichiometry than monomers that participate in addition polymerization: : Other classifications include: *natural vs synthetic monomers, e.g. glycine vs caprolactam, respectively *polar vs nonpolar monomers, e.g. vinyl acetate vs ethylene, respectively *cyclic vs linear, e.g. ethylene oxide vs ethylene glycol, respectively The polymerization of one kind of monomer gives a homopolymer. Many polymers are copolymers, meaning that they are derived from two different monomers. In the case of condensation polymerizations, the r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photolithography
In integrated circuit manufacturing, photolithography or optical lithography is a general term used for techniques that use light to produce minutely patterned thin films of suitable materials over a substrate, such as a silicon wafer, to protect selected areas of it during subsequent etching, deposition, or implantation operations. Typically, ultraviolet light is used to transfer a geometric design from an optical mask to a light-sensitive chemical (photoresist) coated on the substrate. The photoresist either breaks down or hardens where it is exposed to light. The patterned film is then created by removing the softer parts of the coating with appropriate solvents. Conventional photoresists typically consists of three components: resin, sensitizer, and solvent. Photolithography processes can be classified according to the type of light used, such as ultraviolet, deep ultraviolet, extreme ultraviolet, or X-ray. The wavelength of light used determines the minimum feature si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Occupational Safety And Health Administration
The Occupational Safety and Health Administration'' (OSHA ) is a large regulatory agency of the United States Department of Labor that originally had federal visitorial powers to inspect and examine workplaces. Congress established the agency under the Occupational Safety and Health Act OSH Act, which President Richard M. Nixon signed into law on December 29, 1970. OSHA's mission is to "assure safe and healthy working conditions for working men and women by setting and enforcing standards and by providing training, outreach, education, and assistance". The agency is also charged with enforcing a variety of whistleblower statutes and regulations. OSHA's workplace safety inspections have been shown to reduce injury rates and injury costs without adverse effects on employment, sales, credit ratings, or firm survival. History The Bureau of Labor Standards of the Department of Labor has worked on some work safety issues since its creation in 1922. Economic boom and associated l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1,6-Hexanediol Diacrylate
1,6-Hexanediol diacrylate (HDDA or HDODA) is a difunctional acrylate ester monomer used in the manufacture of polymers. It is particularly useful for use in ultraviolet light cure applications. Furthermore, it is also used in adhesives, sealants, alkyd coatings, elastomers, photopolymers, and inks for improved adhesion, hardness, abrasion and heat resistance. Like other acrylate monomers it is usually supplied with a radical inhibitor such as hydroquinone added. Preparation The material is prepared by acid-catalyzed esterification of 1,6-hexanediol with acrylic acid. Other uses As the molecule has acrylic functionality, it is capable of undergoing the Michael reaction with an amine. This allows it use in epoxy chemistry where its use speeds up the cure time considerably. See also * TMPTA (trimethylolpropane triacrylate), a triacrylate crosslinker * Pentaerythritol tetraacrylate Pentaerythritol tetraacrylate (PETA or sometimes PETTA,PETRA) is an organic compound. It is a tetr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pentaerythritol Tetraacrylate
Pentaerythritol tetraacrylate (PETA or sometimes PETTA,PETRA) is an organic compound. It is a tetrafunctional acrylate ester used as a monomer in the manufacture of polymers. As it is a polymerizable acrylate monomer it is nearly always supplied with a polymerisation inhibitor such as MEHQ (monomethyl ether hydroquinone) added. Uses PETA is part of a family of acrylates used in epoxy resin chemistry and ultraviolet cure of coatings. Similar monomers used are 1,6-hexanediol diacrylate and TMPTA trimethylol propane triacrylate. It is a derivative of pentaerythritol One of the key uses of the material is in polymeric synthesis where it can form micelles and block copolymers. The molecule's acrylate group functionality enables the molecule to do the Michael reaction with amines. It is therefore sometimes used in epoxy chemistry enabling a large reduction in cure time. As the molecule has 4 functional acrylate groups it confers high cross-link density. Ethoxylation maybe used to pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epoxy
Epoxy is the family of basic components or cured end products of epoxy resins. Epoxy resins, also known as polyepoxides, are a class of reactive prepolymers and polymers which contain epoxide groups. The epoxide functional group is also collectively called ''epoxy''. The IUPAC name for an epoxide group is an oxirane. Epoxy resins may be reacted (cross-linked) either with themselves through catalytic homopolymerisation, or with a wide range of co-reactants including polyfunctional amines, acids (and acid anhydrides), phenols, alcohols and thiols (usually called mercaptans). These co-reactants are often referred to as hardeners or curatives, and the cross-linking reaction is commonly referred to as curing. Reaction of polyepoxides with themselves or with polyfunctional hardeners forms a thermosetting polymer, often with favorable mechanical properties and high thermal and chemical resistance. Epoxy has a wide range of applications, including metal coatings, composites, use in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amine
In chemistry, amines (, ) are compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are formally derivatives of ammonia (), wherein one or more hydrogen atoms have been replaced by a substituent such as an alkyl or aryl group (these may respectively be called alkylamines and arylamines; amines in which both types of substituent are attached to one nitrogen atom may be called alkylarylamines). Important amines include amino acids, biogenic amines, trimethylamine, and aniline; Inorganic derivatives of ammonia are also called amines, such as monochloramine (). The substituent is called an amino group. Compounds with a nitrogen atom attached to a carbonyl group, thus having the structure , are called amides and have different chemical properties from amines. Classification of amines Amines can be classified according to the nature and number of substituents on nitrogen. Aliphatic amines contain only H and alkyl substituents. A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Michael Reaction
In organic chemistry, the Michael reaction or Michael addition is a reaction between a Michael donor (an enolate or other nucleophile) and a Michael acceptor (usually an α,β-unsaturated carbonyl) to produce a Michael adduct by creating a carbon-carbon bond at the acceptor's β-carbon. It belongs to the larger class of conjugate additions and is widely used for the mild formation of carbon-carbon bonds. The Michael addition is an important atom-economical method for diastereoselective and enantioselective C–C bond formation, and many asymmetric variants exist : In this general Michael addition scheme, either or both of R and R' on the nucleophile (the Michael donor) represent electron-withdrawing substituents such as acyl, cyano, nitro, or sulfone groups, which make the adjacent methylene hydrogen acidic enough to form a carbanion when reacted with the base, ''B:''. For the alkene (the Michael acceptor), the R" substituent is usually a carbonyl, which makes the compound ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elastomer
An elastomer is a polymer with viscoelasticity (i.e. both viscosity and elasticity) and with weak intermolecular forces, generally low Young's modulus and high failure strain compared with other materials. The term, a portmanteau of ''elastic polymer'', is often used interchangeably with rubber, although the latter is preferred when referring to vulcanisates. Each of the monomers which link to form the polymer is usually a compound of several elements among carbon, hydrogen, oxygen and silicon. Elastomers are amorphous polymers maintained above their glass transition temperature, so that considerable molecular reconformation is feasible without breaking of covalent bonds. At ambient temperatures, such rubbers are thus relatively compliant ( E ≈ 3 M Pa) and deformable. Their primary uses are for seals, adhesives and molded flexible parts. Application areas for different types of rubber are manifold and cover segments as diverse as tires, soles for shoes, and damping and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Screen Printing
Screen printing is a printing technique where a mesh is used to transfer ink (or dye) onto a substrate, except in areas made impermeable to the ink by a blocking stencil. A blade or squeegee is moved across the screen to fill the open mesh apertures with ink, and a reverse stroke then causes the screen to touch the substrate momentarily along a line of contact. This causes the ink to wet the substrate and be pulled out of the mesh apertures as the screen springs back after the blade has passed. One colour is printed at a time, so several screens can be used to produce a multi-coloured image or design. Traditionally, silk was used in the process. Currently, synthetic threads are commonly used in the screen printing process. The most popular mesh in general use is made of polyester. There are special-use mesh materials of nylon and stainless steel available to the screen-printer. There are also different types of mesh size which will determine the outcome and look of the fi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dental Composite
Dental composite resins (better referred to as "resin-based composites" or simply "filled resins") are dental cements made of synthetic resins. Synthetic resins evolved as restorative materials since they were insoluble, of good tooth-like appearance, insensitive to dehydration, easy to manipulate and inexpensive. Composite resins are most commonly composed of Bis-GMA and other dimethacrylate monomers (TEGMA, UDMA, HDDMA), a filler material such as silica and in most applications, a photoinitiator. Dimethylglyoxime is also commonly added to achieve certain physical properties such as flow-ability. Further tailoring of physical properties is achieved by formulating unique concentrations of each constituent. Many studies have compared the lesser longevity of resin-based composite restorations to the longevity of silver-mercury amalgam restorations. Depending on the skill of the dentist, patient characteristics and the type and location of damage, composite restorations can have sim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trimethylolpropane
300 C--> Trimethylolpropane (TMP) is the organic compound with the formula CH3CH2C(CH2OH)3. This colourless to white solid with a faint odor is a triol. Containing three hydroxy functional groups, TMP is a widely used building block in the polymer industry. Production TMP is produced via a two step process, starting with the condensation of butanal with formaldehyde: :CH3CH2CH2CHO + 2 CH2O → CH3CH2C(CH2OH)2CHO The second step entails a Cannizaro reaction: :CH3CH2C(CH2OH)2CHO + CH2O + NaOH → CH3CH2C(CH2OH)3 + NaO2CH Approximately 200,000,000 kg are produced annually in this way.Peter Werle, Marcus Morawietz, Stefan Lundmark, Kent Sörensen, Esko Karvinen, Juha Lehtonen “Alcohols, Polyhydric” in Ullmann’s Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2008. Applications TMP is mainly consumed as a precursor to alkyd resins. Otherwise, acrylated and alkoxylated TMP's are used as multifunctional monomers to produce various coatings, Ethoxylated a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
