Chembox verifiedrevid 443418087 ImageFile Lactide.png ImageSize 120px ImageFile1 R,R Lactide xtal.png ImageCaption1 Crystal structure of R , R lactide. ref cite journal doi 10.1107 S0567740882006840 title Structure of 3,6 dimethyl 1,4 dioxane 2,5 dione D ,D L ,L lactide year 1982 last1 Van Hummel first1 G. J. last2 Harkema first2 S. last3 Kohn first3 F. E. last4 Feijen first4 J. journal Acta Crys. volume B38 issue 5 pages 1679 ref ImageFile2 meso Lactide xtal.png ImageCaption2 Crystal structure of meso lactide. ref cite journal doi 10.1021 ja002160g title Molecular Design of Single Site Metal Alkoxide Catalyst Precursors for Ring Opening Polymerization Reactions Leading to Polyoxygenates. 1. Polylactide Formation by Achiral and Chiral Magnesium and Zinc Alkoxides, 3 L MOR, Where L Trispyrazolyl and Trisindazolylborate Ligands year 2000 last1 Chisholm first1 Malcolm H. last2 Eilerts first2 Nancy W. last3 Huffman first3 John C. last4 Iyer first4 Suri S. last5 Pacold first5 Martha last6 Phomphrai ... Chembox Identifiers CASNo Ref cascite correct ?? CASNo 4511 42 6 CASNo Comment S , S Lactide CASOther 25038 75 9 R , R Lactide , 13076 19 2 R , S Lactide meso Lactide , 26680 10 4 mixture of three isomers Section2 Chembox Properties C 6 H 8 O 4 MeltingPt 95 97 C S , S Lactide and R , R Lactide ... RPhrases R36 37 38 SPhrases S26 S37 39 Lactide is the cyclic di ester of lactic acid , i.e., 2 hydroxypropionic ... cyclic diester known as lactide . Lactides may be prepared by heating lactic acid in the presence of an acid catalyst . In general, a lactide is the cyclic diester, i.e., the di lactone of two molecules ... forms, R lactic acid and S lactic acid, may exist. Thus, lactide formed from two equivalents of lactic acid consists of two stereocenters. Three different stereoisomers of lactide are known File Lactide Stereoisomers Structural Formulae.png thumb left 350px R , R Lactide left above , S , S lactide right above and meso lactide below Clear left Polymerization Lactide can be polymerization ... more details
unreferenced date October 2009 Polilactofate PLF is a copolymer of Polylactic acid PDLL poly d,l lactide and a phosphoester . chemistry stub Category Copolymers ... more details
unreferenced date October 2010 The term pre polymer refers to a monomer or system of monomers that have been reacted to an intermediate molecular weight state. This material is capable of further polymerization by reactive groups to a fully cured high molecular weight state. As such, mixtures of reactive polymers with un reacted monomers may also be referred to as pre polymers. The term pre polymer and polymer precursor may be interchanged. Lactic acid as a polymer precursor Main polylactic acid Two molecule s of lactic acid can be dehydrated to lactide , a cyclic lactone . A variety of catalyst s can polymerise lactide to either Heterotactis heterotactic or syndiotactic polylactide , which as biodegradable polyesters with valuable inter alia medical properties are currently attracting much attention. Nowadays, lactic acid is used as a monomer for producing polylactic acid PLA which later has application as biodegradable plastic . This kind of plastic is a good option for substituting conventional plastic produced from petroleum oil because of low emission of carbon dioxide . The commonly used process in producing lactic acid is via Industrial fermentation fermentation , and later to obtain the polylactic acid, the polymerization process follows. Category Plastics Category Polyamides Category Polymers Category Polyurethanes Category Soft matter Category Synthetic resins fr Pr polym re ... more details
v.1.png thumb 600px Catalytic and thermolytic ring opening polymerization of lactide left to polylactide ... a single esterfication and then catalytically cyclized to make a cyclic lactide ester . Although ... of poly DL lactide PDLLA which is amorphous. Use of stereospecific catalysts can lead to heterotactic ... chiral nature of lactic acid, several distinct forms of polylactide exist poly L lactide PLLA is the product resulting from polymerization of L,L lactide also known as L lactide . PLLA has a crystallinity ... with PDLA poly D lactide . PDLA and PLLA form a highly regular stereocomplex with increased crystallinity ... transparent. There is also poly L lactide co D,L lactide PLDLLA used as PLDLLA TCP scaffolds for bone ... of several thousand tons. In March 2010, PURAC began construction on a 75,000 ton year lactide plant ... lactide, PURAC partners will be able to use stereo complex technologies to produce new PLA grades ... more details
and in Shorea laeviforia Lactide Tergallic acid dilactone can be found in Rhynchosia volubilis ... , a cyclic amide Lactim , a cyclic imide Lactide , a cyclic di ester Halolactonization References ... more details
L lactide and ethylene glycol with long center PEG block. Journal of Applied Polymer Science Volume ... copolymers from L lactide, glycolide, and PPG. Journal of Applied Polymer Science Volume 73 Issue 5 ... ethylene glycol, L lactide, and epsilon caprolactone. Journal of Applied Polymer Science Volume 83 ... more details
Image PLGA.svg thumb Structure of poly lactic co glycolic acid . x number of units of lactic acid y number of units of glycolic acid . For the tumour see polymorphous low grade adenocarcinoma PLGA or poly lactic co glycolic acid is a copolymer which is used in a host of Food and Drug Administration FDA approved therapeutic devices, owing to its Biodegradation biodegradability and biocompatibility . PLGA is synthesized by means of random ring opening co polymerization of two different monomer s, the cyclic dimers 1,4 dioxane 2,5 diones of glycolic acid and lactic acid . Common catalysts used in the preparation of this polymer include tin II 2 ethylhexanoate , tin II alkoxide s, or aluminum isopropoxide . During polymerization, successive monomeric units of glycolic or lactic acid are linked together in PLGA by ester linkages, thus yielding a linear, aliphatic polyester as a product. ref cite journal author Astete, C. E. and Sabliov, C. M. title Synthesis and characterization of PLGA nanoparticles year 2006 journal Journal of Biomaterials Science Polymer Edition volume 17 issue 3 pages 247 289 doi 10.1163 156856206775997322 pmid 16689015 ref Depending on the ratio of lactide to glycolide used for the polymerization, different forms of PLGA can be obtained these are usually identified in regard to the monomers ratio used e.g. PLGA 75 25 identifies a copolymer whose composition is 75 lactic acid and 25 glycolic acid . All PLGAs are Amorphous solid amorphous rather than crystallinity crystalline and show a glass transition temperature in the range of 40 60 C. Unlike the homopolymer s of lactic acid polylactide and glycolic acid polyglycolide which show poor solubilities, PLGA can be dissolved by a wide range of common solvent s, including chlorine chlorinated solvents, tetrahydrofuran , acetone or ethyl acetate . PLGA degrades by hydrolysis of its ester linkages in the presence of water molecule water . It has been shown that the time required for degradation of PLGA is ... more details
, so the net carbon released from the process is zero. Image Lactide.png thumb 144px right Lactide ... acid is produced by fermenting corn and converted to lactide , the cyclic dimer ester of lactic acid using an efficient, tin catalyzed cyclization. The L,L lactide enantiomer is isolated by distillation ..., and reduces the amount of fats and oils wasted. Unfortunately, lactide base polymers do ... more details
Image Making of a DNA vaccine.jpg thumb 250px right The making of a DNA vaccine. DNA vaccination is a technique for protecting an organism against disease by injecting it with genetically engineered naked DNA DNA to produce an immunological response . Nucleic acid vaccines are still experimental, and have been applied to a number of virus viral , bacterial and parasitic models of disease, as well as to several tumour models. DNA vaccines have a number of advantages over conventional vaccines, including the ability to induce a wider range of immune response types. Many believe vaccine s are among the greatest achievements of modern medicine in industrial nations, they have eliminated naturally occurring cases of smallpox , and nearly eliminated polio , while other diseases, such as typhus , rotavirus , hepatitis A and B and others are well controlled. Conventional vaccines, however, only cover a small number of diseases, and infections that lack effective vaccines kill millions of people every year, with AIDS , hepatitis C and malaria being particularly common. First generation vaccines are whole organism vaccines either live and Attenuated virus weakened , or killed forms. ref name Alarcon1999 cite journal author Alarcon JB, Waine GW, McManus DP title DNA vaccines technology and application as anti parasite and anti microbial agents journal Adv. Parasitol. volume 42 issue pages 343 410 year 1999 pmid 10050276 doi 10.1016 S0065 308X 08 60152 9 ref Live, attenuated vaccines, such as smallpox and polio vaccines, are able to induce Cytotoxic T cell killer T cell T sub C sub or CTL responses, Helper T cell helper T cell T sub H sub responses and antibody immunity. However, there is a small risk that attenuated forms of a pathogen can revert to a dangerous form, and may still be able to cause disease in immunocompromised vaccine recipients such as those with AIDS . While killed vaccines do not have this risk, they cannot generate specific killer T cell responses, and may ... more details
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