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Medical Grade Silicone
Medical grade silicones are silicones tested for biocompatibility and are appropriate to be used for medical applications. In the United States, the Food and Drug Administration (FDA) Center for Devices and Radiological Health (CDRH) regulates devices implanted into the body. It does not regulate materials other than certain dental materials. The FDA regulate silicones used in food contact under the auspices of the Center for Food Safety and Nutrition (CFSAN) and for use in pharmaceuticals under the auspices of the Center for Drug Evaluation and Research (CDER). Medical grade silicones are generally grouped into three categories: non implantable, short term implantable, and long-term implantable. Materials approved as Class V and VI can be considered medical grade. Most medical grade silicones are at least Class VI certified. Silicone suppliers and some silicone prototyping companies provide guidelines for material use. Uses * Tubing * Drains * Feeding tubes * Catheters * Impl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silicone
In Organosilicon chemistry, organosilicon and polymer chemistry, a silicone or polysiloxane is a polymer composed of repeating units of siloxane (, where R = Organyl group, organic group). They are typically colorless oils or elastomer, rubber-like substances. Silicones are used in sealants, adhesives, lubricants, medicine, cooking utensils, thermal insulation, and electrical insulation. Some common forms include silicone oil, silicone grease, grease, silicone rubber, rubber, silicone resin, resin, and Caulking, caulk. Silicone is often confused with one of its constituent elements, silicon, but they are distinct substances. Silicon is a chemical element, a hard dark-grey semiconductor, semiconducting metalloid, which in its crystalline form is used to make integrated circuits ("electronic chips") and solar cells. Silicones are compounds that contain silicon, carbon, hydrogen, oxygen, and perhaps other kinds of atoms as well, and have many very different physical and chemical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fatigue (material)
In materials science, fatigue is the initiation and propagation of cracks in a material due to cyclic loading. Once a fatigue crack has initiated, it grows a small amount with each loading cycle, typically producing striations on some parts of the fracture surface. The crack will continue to grow until it reaches a critical size, which occurs when the stress intensity factor of the crack exceeds the fracture toughness of the material, producing rapid propagation and typically complete fracture of the structure. Fatigue has traditionally been associated with the failure of metal components which led to the term metal fatigue. In the nineteenth century, the sudden failing of metal railway axles was thought to be caused by the metal crystallising because of the brittle appearance of the fracture surface, but this has since been disproved. Most materials, such as composites, plastics and ceramics, seem to experience some sort of fatigue-related failure. To aid in predicting the f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Implants (medicine)
Implant can refer to: Medicine *Implant (medicine), or specifically: ** Brain implant **Breast implant ** Buttock implant **Cochlear implant ** Contraceptive implant **Dental implant ** Fetal tissue implant ** Implantable cardioverter-defibrillator ** Orthopedic implant ** Prosthetic implant ** Retinal implant ** Subdermal implant ** Transdermal implant Alternative * Alien implants * Extraocular implant * Implant (body modification) * Implant (thought insertion) *Microchip implant (animal) (human) *'' The Implant'', a television episode of ''Seinfeld ''Seinfeld'' ( ) is an American television sitcom created by Larry David and Jerry Seinfeld that originally aired on NBC from July 5, 1989, to May 14, 1998, with a total of nine seasons consisting of List of Seinfeld episodes, 180 episodes. It ...'' See also * History of dental treatments * Implantation (other) * Osseointegration * Osseoincorporation {{disambig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elastomers
An elastomer is a polymer with viscoelasticity (i.e. both viscosity and Elasticity (physics), elasticity) and with weak intermolecular forces, generally low Young's modulus (E) and high failure strain compared with other materials. The term, a portmanteau of ''elastic polymer'', is often used interchangeably with ''Synthetic rubber, rubber'', although the latter is preferred when referring to Vulcanization, vulcanisates. Each of the monomers which link to form the polymer is usually a compound of several Chemical elements, elements among carbon, hydrogen, oxygen and silicon. Elastomers are amorphous polymers maintained above their glass transition temperature, so that considerable Segmental motion, molecular reconformation is feasible without breaking of covalent bonds. Rubber-like solids with elastic properties are called elastomers. Polymer chains are held together in these materials by relatively weak molecule, intermolecular bonds, which permit the polymers to stretch in r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biomaterials
A biomaterial is a substance that has been engineered to interact with biological systems for a medical purpose – either a therapeutic (treat, augment, repair, or replace a tissue function of the body) or a diagnostic one. The corresponding field of study, called biomaterials science or biomaterials engineering, is about fifty years old. It has experienced steady growth over its history, with many companies investing large amounts of money into the development of new products. Biomaterials science encompasses elements of medicine, biology, chemistry, tissue engineering and materials science. A biomaterial is different from a biological material, such as bone, that is produced by a biological system. However, "biomaterial" and "biological material" are often used interchangeably. Further, the word "bioterial" has been proposed as a potential alternate word for biologically-produced materials such as bone, or fungal biocomposites. Additionally, care should be exercised in defini ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plastics Engineering
Polymer engineering is generally an engineering field that designs, analyses, and modifies polymer materials. Polymer engineering covers aspects of the petrochemical industry, polymerization, structure and characterization of polymers, properties of polymers, compounding and processing of polymers and description of major polymers, structure property relations and applications. History The word “polymer” was introduced by the Swedish chemist J. J. Berzelius. He considered, for example, benzene (C6H6) to be a polymer of ethyne (C2H2). Later, this definition underwent a subtle modification. The history of human use of polymers has been long since the mid-19th century, when it entered the chemical modification of natural polymers. In 1839, Charles Goodyear found a critical advance in the research of rubber vulcanization, which has turned natural rubber into a practical engineering material. In 1870, J. W. Hyatt uses camphor to plasticize nitrocellulose to make nitrocellulose pl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polymers
A polymer () is a substance or material that consists of very large molecules, or macromolecules, that are constituted by many repeating subunits derived from one or more species of monomers. Due to their broad spectrum of properties, both synthetic and natural polymers play essential and ubiquitous roles in everyday life. Polymers range from familiar synthetic plastics such as polystyrene to natural biopolymers such as DNA and proteins that are fundamental to biological structure and function. Polymers, both natural and synthetic, are created via polymerization of many small molecules, known as monomers. Their consequently large molecular mass, relative to small molecule compounds, produces unique physical properties including toughness, high elasticity, viscoelasticity, and a tendency to form amorphous and semicrystalline structures rather than crystals. Polymers are studied in the fields of polymer science (which includes polymer chemistry and polymer p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silicone Rubber
Silicone rubber is an elastomer composed of silicone—itself a polymer—containing silicon together with carbon, hydrogen, and oxygen. Silicone rubbers are widely used in industry, and there are multiple formulations. Silicone rubbers are often one- or two-part polymers, and may contain fillers to improve properties or reduce cost. Silicone rubber is generally non-reactive, stable, and resistant to extreme environments and temperatures from while still maintaining its useful properties. Due to these properties and its ease of manufacturing and shaping, silicone rubber can be found in a wide variety of products, including voltage line insulators; automotive applications; cooking, baking, and food storage products; apparel such as undergarments, sportswear, and footwear; electronics; medical devices and implants; and in home repair and hardware, in products such as silicone sealants. The term "silicone" is actually a misnomer. The suffix ''-one'' is used by chemists to den ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Pharmacopeia
The ''United States Pharmacopeia'' (''USP'') is a pharmacopeia (compendium of drug information) for the United States published annually by the over 200-year old United States Pharmacopeial Convention (usually also called the USP), a nonprofit organization that owns the trademark and also owns the copyright on the pharmacopeia itself. The ''USP'' is published in a combined volume with the ''National Formulary'' (a formulary) as the USP-NF. If a drug ingredient or drug product has an applicable ''USP'' quality standard (in the form of a ''USP-NF'' monograph), it must conform in order to use the designation "USP" or "NF". Drugs subject to ''USP'' standards include both human drugs ( prescription, over-the-counter, or otherwise) and animal drugs. ''USP-NF'' standards also have a role in US federal law; a drug or drug ingredient with a name recognized in ''USP-NF'' is considered adulterated if it does not satisfy compendial standards for strength, quality, or purity. USP also ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silicone
In Organosilicon chemistry, organosilicon and polymer chemistry, a silicone or polysiloxane is a polymer composed of repeating units of siloxane (, where R = Organyl group, organic group). They are typically colorless oils or elastomer, rubber-like substances. Silicones are used in sealants, adhesives, lubricants, medicine, cooking utensils, thermal insulation, and electrical insulation. Some common forms include silicone oil, silicone grease, grease, silicone rubber, rubber, silicone resin, resin, and Caulking, caulk. Silicone is often confused with one of its constituent elements, silicon, but they are distinct substances. Silicon is a chemical element, a hard dark-grey semiconductor, semiconducting metalloid, which in its crystalline form is used to make integrated circuits ("electronic chips") and solar cells. Silicones are compounds that contain silicon, carbon, hydrogen, oxygen, and perhaps other kinds of atoms as well, and have many very different physical and chemical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Breast Implant
A breast implant is a prosthesis used to change the size, shape, and contour of a person's breast. In reconstructive plastic surgery, breast implants can be placed to restore a natural looking breast following a mastectomy, to correct congenital defects and deformities of the chest wall or, cosmetically, to enlarge the appearance of the breast through breast augmentation surgery. Complications of implants may include breast pain, rashes, skin changes, infection, rupture, cosmetic changes to the breasts such as asymmetry and hardness, and a fluid collection around the breast. A rare complication associated with textured surfaced implants and polyurethane foam-covered implants is a type of lymphoma (cancer of the immune system) known as breast implant-associated anaplastic large-cell lymphoma (BIA-ALCL). There are four general types of breast implants, defined by their filler material: saline solution, silicone gel, structured and composite filler. The saline implant has an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vulcanization
Vulcanization (British English: vulcanisation) is a range of processes for hardening rubbers. The term originally referred exclusively to the treatment of natural rubber with sulfur, which remains the most common practice. It has also grown to include the hardening of other (synthetic) rubbers via various means. Examples include silicone rubber via room temperature vulcanizing and chloroprene rubber (neoprene) using metal oxides. Vulcanization can be defined as the curing of elastomers, with the terms 'vulcanization' and 'curing' sometimes used interchangeably in this context. It works by forming cross-links between sections of the polymer chain which results in increased rigidity and durability, as well as other changes in the mechanical and electrical properties of the material. Vulcanization, in common with the curing of other thermosetting polymers, is generally irreversible. The word was suggested by William Brockedon (a friend of Thomas Hancock who attained the B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
