The metal-catalyzed reaction tends to cause racemization of the PLA, reducing its stereoregularity compared to the starting material (usually corn starch). The most common route to PLA is the ring-opening polymerization of lactide with various metal catalysts (typically tin octoate) in solution or as a suspension. Two main monomers are used: lactic acid, and the cyclic di-ester, lactide. Several industrial routes afford usable (i.e. The monomer is typically made from fermented plant starch such as from corn, cassava, sugarcane or sugar beet pulp.
The name "polylactic acid" is potentially ambiguous or confusing, because PLA is not a polyacid ( polyelectrolyte), but rather a polyester. Without annealing, however, PLA has the lowest heat resistance of the common 3D printing plastics.Īlthough the name "polylactic acid" is widely used, it does not comply with IUPAC standard nomenclature, which is "poly(lactic acid)". Its low melting point, high strength, low thermal expansion, good layer adhesion, and high heat resistance when annealed make it an ideal material for this purpose. PLA is the most widely used plastic filament material in 3D printing. Its widespread application has been hindered by numerous physical and processing shortcomings. In 2010, PLA had the second highest consumption volume of any bioplastic of the world, although it is still not a commodity polymer. PLA has become a popular material due to it being economically produced from renewable resources. It can also be prepared by ring-opening polymerization of lactide [–C(CHĢ, the cyclic dimer of the basic repeating unit. N, formally obtained by condensation of lactic acid C(CHģ)(OH)HCOOH with loss of water (hence its name). Was subsequently enlarged in 1901, when the original brick building was encased and extended as a three-storey Jacobean style country house, roughcast.Polylactic acid, also known as poly( lactic acid) or polylactide ( PLA), is a thermoplastic polyester with backbone formula (C Socks) are socks that have been knitted so that each toe is individually encased the same way as fingers within a glove.
It is then encased in natural intestine, usually together with a strip of fat, and smoked. Needed] The launcher can be made from fibreglass, or with a fibreglass liner encased in metal.Įach individual CD was encased by a paper sleeve representing the single's original artwork from a particular.Ī sign below the cross states that the original cross is encased inside the wooden cross made of tindalo wood. Milk chocolate encased in a chewy caramel.Ĭadbury Eclairs Orange Twist: Orange flavour Cadbury milk chocolate encased in a chewy caramel. Introduced by the Cadbury company in 1967, the egg is solid milk chocolate encased in a thin coating of hard candy "shell", molded to resemble a miniature. The non- encased condition of their seeds contrasts with the seeds and ovules of flowering.īullet is a small-arms projectile consisting of a soft core (often lead) encased in an outer shell ("jacket") of harder metal, such as gilding metal, cupronickel. Of spirits") refers to a luck and protection amulet made from blubber encased in seal fur. In permanent fortifications the scarp and counterscarp may be encased in stone. Suet, spices, and salt, mixed with stock, and cooked while traditionally encased in the animal's stomach though now often in an artificial casing instead. Reproduction is oviparous and eggs are encased in horny shells. Sausages, in which meat and other ingredients in mostly liquid form are encased and then steamed or boiled to set the contents.Ī box pew is a type of church pew that is encased in panelling and was prevalent in England and other Protestant countries from the 16th to early 19th. Raw pork products and spices encased in pig bladder are aged and the paste spread on open slices of bread which. Pagan, and the second storey added by King Narapatisithu, and both were encased inside a huge stupa built by King Uzana of the Pinya dynasty. Her murder case was called the "concrete- encased high school girl murder case" (女子高生コンクリート詰め殺人事件), due to her body being.
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