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Cellulose Diacetate
Cellulose diacetate, sometimes called diacetate, is a synthetic polymer made by treating cellulose with acetic acid. It consists of two acetyl functional groups on each unit of D-anhydroglucopyranose of the cellulose molecule. It was first developed in the United States. It is fragile since it is based on cellulose. When cellulose diacetate deteriorates, it shrinks and releases acetic acid causing vinegar syndrome. Cellulose diacetate has been used to make fabrics, membranes, filaments, and many consumer products. From 1922 to 1957 it was used to make film stock, mainly in smaller formats such as 8 mm, 16 mm, 35 mm, and 70 mm. It has also been used in seed coating applications. In photography, a film substrate made from cellulose diacetate is called safety film. Cellulose diacetate is hydrophilic and biodegradable. See also * Cellulose acetate In biochemistry, cellulose acetate refers to any acetate ester of cellulose, usually cellulose diacetate. It was first prep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synthetic Polymer
Some familiar household synthetic polymers include: Nylons in textiles and fabrics, Teflon in non-stick pans, Bakelite for electrical switches, polyvinyl chloride (PVC) in pipes, etc. The common PET bottles are made of a synthetic polymer, polyethylene terephthalate. The plastic kits and covers are mostly made of synthetic polymers like polythene, and tires are manufactured from polybutadienes. However, due to the environmental issues created by these synthetic polymers which are mostly non-biodegradable and often synthesized from petroleum, alternatives like bioplastics are also being considered. They are however expensive when compared to the synthetic polymers. Inorganic polymers * Polysiloxane * Polyphosphazene * Polyborazyline Organic polymers The eight most common types of synthetic organic polymers, which are commonly found in households are: * Low-density polyethylene (LDPE) *High-density polyethylene (HDPE) *Polypropylene (PP) *Polyethylene (PE) *Polyvinyl chl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
16 Mm Film
16 mm film is a historically popular and economical Film gauge, gauge of Photographic film, film. 16 mm refers to the width of the film (about inch); other common film gauges include 8 mm film, 8 mm and 35mm movie film, 35 mm. It is generally used for non-theatrical (e.g., industrial, educational, television) film-making, or for low-budget motion pictures. It also existed as a popular amateur or home movie-making format for several decades, alongside 8 mm film and later Super 8 film. Kodak, Eastman Kodak released the first 16 mm "outfit" in 1923, consisting of a Ciné-Kodak camera, Kodascope projector, tripod, screen and splicer, for US$335 (). RCA Records, RCA-Victor introduced a 16 mm sound movie projector in 1932, and developed an optical sound-on-film 16 mm camera, released in 1935. History Eastman Kodak introduced 16 mm film in 1923, as a less expensive alternative to 35mm movie film, 35 mm Film formats, film for amateurs. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cellulose Triacetate
Cellulose triacetate, triacetate, CTA or TAC is a chemical compound produced from cellulose and a source of acetate esters, typically acetic anhydride. Triacetate is commonly used for the creation of fibres and film base. It is chemically similar to cellulose acetate. Its distinguishing characteristic is that in triacetate, at least "92 percent of the hydroxyl groups are acetylated." During the manufacture of triacetate, the cellulose is completely acetylated; whereas in normal cellulose acetate or cellulose diacetate, it is only partially acetylated. Triacetate is significantly more heat resistant than cellulose acetate. History Triacetate, whose chemical formula is 6H7O2(OOCCH3)3sub>n, was first produced commercially in the U.S. in 1954 by Celanese Corporation. Eastman Kodak was a manufacturer of CTA until March 15, 2007. For almost 3 years, Mitsubishi Rayon Co. Ltd. was the only manufacturer. In 2010, Eastman Chemical announced a 70% increase in cellulose triacetate o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cellulose Acetate
In biochemistry, cellulose acetate refers to any acetate ester of cellulose, usually cellulose diacetate. It was first prepared in 1865. A bioplastic, cellulose acetate is used as a film base in photography, as a component in some coatings, and as a frame material for eyeglasses; it is also used as a synthetic fiber in the manufacture of Cigarette filter, cigarette filters and Playing card, playing cards. In cellulose acetate film, photographic film, cellulose acetate film replaced nitrate film in the 1950s, being far less flammable and cheaper to produce. Water-soluble cellulose acetate (WSCA) has been used as a Prebiotic (nutrition), dietary fiber (prebiotic), in relation with weight loss and Akkermansia muciniphila. History In 1865, French chemist Paul Schützenberger discovered that cellulose reacts with acetic anhydride to form cellulose acetate. The German chemists Arthur Eichengrün and Theodore Becker invented the first soluble forms of cellulose acetate in 1903. In 190 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biodegradable
Biodegradation is the breakdown of organic matter by microorganisms, such as bacteria and fungi. It is generally assumed to be a natural process, which differentiates it from composting. Composting is a human-driven process in which biodegradation occurs under a specific set of circumstances. The process of biodegradation is threefold: first an object undergoes biodeterioration, which is the mechanical weakening of its structure; then follows biofragmentation, which is the breakdown of materials by microorganisms; and finally assimilation, which is the incorporation of the old material into new cells. In practice, almost all chemical compounds and materials are subject to biodegradation, the key element being time. Things like vegetables may degrade within days, while glass and some plastics take many millennia to decompose. A standard for biodegradability used by the European Union is that greater than 90% of the original material must be converted into , water and minerals b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrophilic
A hydrophile is a molecule or other molecular entity that is attracted to water molecules and tends to be dissolved by water.Liddell, H.G. & Scott, R. (1940). ''A Greek-English Lexicon'' Oxford: Clarendon Press. In contrast, hydrophobes are not attracted to water and may seem to be repelled by it. Hygroscopics ''are'' attracted to water, but are not dissolved by water. Molecules A hydrophilic molecule or portion of a molecule is one whose interactions with water and other polar substances are more thermodynamically favorable than their interactions with oil or other hydrophobic solvents. They are typically charge-polarized and capable of hydrogen bonding. This makes these molecules soluble not only in water but also in polar solvents. Hydrophilic molecules (and portions of molecules) can be contrasted with hydrophobic molecules (and portions of molecules). In some cases, both hydrophilic and hydrophobic properties occur in a single molecule. An example of these amphiphilic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cellulose Acetate Film
Cellulose acetate film, or safety film, is used in photography as a base material for photographic emulsions. It was introduced in the early 20th century by film manufacturers and intended as a safe film base replacement for unstable and highly flammable nitrate film. Cellulose diacetate film was first employed commercially for photographic film in 1909. Cellulose acetate propionate and cellulose acetate butyrate were introduced in the 1930s, and cellulose triacetate in the late 1940s. Acetate films were later replaced by polyester bases. The motion picture industry continued to use cellulose nitrate supports until the introduction of cellulose triacetate in 1948, which met the rigorous safety and performance standards set by the cinematographic industry. The chemical instability of cellulose acetate material, unrecognized at the time of its introduction, has since become a major problem for film archives and collections. History Cellulose diacetate film was first created by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
70 Mm Film
70 mm film (or 65 mm film) is a wide high-resolution film gauge for motion picture photography, with a negative area nearly 3.5 times as large as the standard 35 mm motion picture film format. As used in cameras, the film is wide. For projection, the original 65 mm film is printed on film. The additional 5 mm contains the four magnetic stripes, holding six tracks of stereophonic sound. Although later 70 mm prints use digital sound encoding (specifically the DTS format), the vast majority of existing and surviving 70 mm prints pre-date this technology. Each frame is five perforations tall (i.e., 23.8125 mm or 15/16 inches tall), with an image aspect ratio of 2.2:1. The use of anamorphic Ultra Panavision 70 lenses squeezes an ultra-wide 2.76:1 aspect ratio horizontally into that 2.2:1 imaging area. To this day, Ultra Panavision 70 produces the widest picture size in the history of filmmaking; surpassed only by Polyvision, which was on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
35mm Movie Film
35 mm film is a film gauge used in filmmaking, and the film standard. In motion pictures that record on film, 35 mm is the most commonly used gauge. The name of the gauge is not a direct measurement, and refers to the nominal width of the 35 mm format photographic film, which consists of strips wide. The standard negative pulldown, image exposure length on 35 mm for movies ("single-frame" format) is four film perforations, perforations per Film frame, frame along both edges, which results in 16 frames per foot of film. A variety of largely proprietary gauges were devised for the numerous camera and projection systems being developed independently in the late 19th and early 20th centuries, along with various film feeding systems. This resulted in cameras, projectors, and other equipment having to be calibrated to each gauge. The 35 mm width, originally specified as inches, was introduced around 1890 by William Kennedy Dickson and Thomas Edison, using 120 film st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
8 Mm Film
8 mm film is a motion picture film format in which the film strip is wide. It exists in two main versions – the original standard 8 mm film, also known as regular 8 mm, and Super 8. Although both standard 8 mm and Super 8 are 8 mm wide, Super 8 has a larger image area because of its smaller and more widely spaced perforations. There are also two other varieties of Super 8 – Single 8 mm and Straight-8 – that require different cameras but produce a final film with the same dimensions. Standard 8 The standard 8 mm (also known as regular 8 or double 8) film format was developed by the Eastman Kodak company during the Great Depression and released to the market in 1932 to create a home movie format that was less expensive than 16 mm. Double 8 spools actually contain a 16 mm film with twice as many perforations along each edge as normal 16 mm film; on its first pass through the camera, the film is exposed only al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cellulose
Cellulose is an organic compound with the chemical formula, formula , a polysaccharide consisting of a linear chain of several hundred to many thousands of glycosidic bond, β(1→4) linked glucose, D-glucose units. Cellulose is an important structural component of the primary cell wall of green plants, many forms of algae and the oomycetes. Some species of bacteria secrete it to form biofilms. Cellulose is the most abundant biopolymer, organic polymer on Earth. The cellulose content of cotton fibre is 90%, that of wood is 40–50%, and that of dried hemp is approximately 57%. Cellulose is mainly used to produce paperboard and paper. Smaller quantities are converted into a wide variety of derivative products such as cellophane and rayon. Conversion of cellulose from energy crops into biofuels such as cellulosic ethanol is under development as a renewable fuel source. Cellulose for industrial use is mainly obtained from wood pulp and cotton. Cellulose is also greatly affected by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Film Stock
Film stock is an analog medium that is used for recording motion pictures or animation. It is recorded on by a movie camera, developed, edited, and projected onto a screen using a movie projector. It is a strip or sheet of transparent plastic film base coated on one side with a gelatin emulsion containing microscopically small light-sensitive silver halide crystals. The sizes and other characteristics of the crystals determine the sensitivity, contrast and resolution of the film.Karlheinz Keller et al. "Photography" in Ullmann's Encyclopedia of Industrial Chemistry, 2005, Wiley-VCH, Weinheim. The emulsion will gradually darken if left exposed to light, but the process is too slow and incomplete to be of any practical use. Instead, a very short exposure to the image formed by a camera lens is used to produce only a very slight chemical change, proportional to the amount of light absorbed by each crystal. This creates an invisible latent image in the emulsion, which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
