Lactide

Last updated
Lactide
Lactide.svg
Names
Preferred IUPAC name
3,6-Dimethyl-1,4-dioxan-2,5-dione
Other names
Dilactid
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.002.245 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 202-468-3
PubChem CID
UNII
  • InChI=1S/C6H8O4/c1-3-5(7)10-4(2)6(8)9-3/h3-4H,1-2H3
    Key: JJTUDXZGHPGLLC-UHFFFAOYSA-N
  • CC1C(=O)OC(C(=O)O1)C
Properties
C6H8O4
Molar mass 144.126 g·mol−1
Melting point 95 to 97 °C (203 to 207 °F; 368 to 370 K) [(S,S)-Lactide and (R,R)-Lactide] [2]
Hydrolyses to lactic acid [2]
Solubility soluble in chloroform, methanol
slightly soluble in benzene

[2]

Hazards
GHS labelling:
GHS-pictogram-exclam.svg
Warning
H319
P264, P280, P305+P351+P338, P337+P313
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Lactide is the lactone cyclic ester derived by multiple esterification between two (usually) or more molecules from lactic acid (2-hydroxypropionic acid) or other hydroxy carboxylic acid. They are designated as dilactides, trilactides, etc., according to the number of hydroxy acid residues. The dilactide derived from lactic acid has the formula [CH(CH3)CO2]2. All lactides are colorless or white solids. This lactide has attracted interest because it is derived from abundant renewable resources and is the precursor to a biodegradable plastic. [3]

Contents

Stereoisomers

The dilactide derived from lactic acid can exist in three different stereoisomeric forms. This complexity arises because lactic acid is chiral. These enantiomers do not racemize readily.

Lactide Stereoisomers Structural Formulae.png
(R,R)-Lactide (left above), (S,S)-lactide (right above) and meso-lactide (below)

All three stereoisomers undergo epimerisation in the presence of organic and inorganic bases in solution. [4]

Polymerization

Lactide can be polymerized to polylactic acid (polylactide). Depending on the catalyst, syndiotactic or a heterotactic polymers can result. The resulting materials, polylactic acid, have many attractive properties. [5] [6]

Polylactide synthesis v.1.png

Related Research Articles

<span class="mw-page-title-main">Biopolymer</span> Polymer produced by a living organism

Biopolymers are natural polymers produced by the cells of living organisms. Like other polymers, biopolymers consist of monomeric units that are covalently bonded in chains to form larger molecules. There are three main classes of biopolymers, classified according to the monomers used and the structure of the biopolymer formed: polynucleotides, polypeptides, and polysaccharides. The Polynucleotides, RNA and DNA, are long polymers of nucleotides. Polypeptides include proteins and shorter polymers of amino acids; some major examples include collagen, actin, and fibrin. Polysaccharides are linear or branched chains of sugar carbohydrates; examples include starch, cellulose, and alginate. Other examples of biopolymers include natural rubbers, suberin and lignin, cutin and cutan, melanin, and polyhydroxyalkanoates (PHAs).

<span class="mw-page-title-main">Biodegradation</span> Decomposition by living organisms

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.

<span class="mw-page-title-main">Lactic acid</span> Organic acid

Lactic acid is an organic acid. It has the molecular formula C3H6O3. It is white in the solid state and it is miscible with water. When in the dissolved state, it forms a colorless solution. Production includes both artificial synthesis as well as natural sources. Lactic acid is an alpha-hydroxy acid (AHA) due to the presence of a hydroxyl group adjacent to the carboxyl group. It is used as a synthetic intermediate in many organic synthesis industries and in various biochemical industries. The conjugate base of lactic acid is called lactate (or the lactate anion). The name of the derived acyl group is lactoyl.

Lactones are cyclic carboxylic esters. They are derived from the corresponding hydroxycarboxylic acids by esterification. They can be saturated or unsaturated. Some contain heteroatoms replacing one or more carbon atoms of the ring.

Ingeo is a range of polylactic acid (PLA) biopolymers owned by NatureWorks.

<span class="mw-page-title-main">Polyglycolide</span> Chemical compound

Polyglycolide or poly(glycolic acid) (PGA), also spelled as polyglycolic acid, is a biodegradable, thermoplastic polymer and the simplest linear, aliphatic polyester. It can be prepared starting from glycolic acid by means of polycondensation or ring-opening polymerization. PGA has been known since 1954 as a tough fiber-forming polymer. Owing to its hydrolytic instability, however, its use has initially been limited. Currently polyglycolide and its copolymers (poly(lactic-co-glycolic acid) with lactic acid, poly(glycolide-co-caprolactone) with ε-caprolactone and poly (glycolide-co-trimethylene carbonate) with trimethylene carbonate) are widely used as a material for the synthesis of absorbable sutures and are being evaluated in the biomedical field.

<span class="mw-page-title-main">Polyhydroxyalkanoates</span> Polyester family

Polyhydroxyalkanoates or PHAs are polyesters produced in nature by numerous microorganisms, including through bacterial fermentation of sugars or lipids. When produced by bacteria they serve as both a source of energy and as a carbon store. More than 150 different monomers can be combined within this family to give materials with extremely different properties. These plastics are biodegradable and are used in the production of bioplastics.

<span class="mw-page-title-main">PLGA</span> Copolymer of varying ratios of polylactic acid and polyglycolic acid

PLGA, PLG, 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 biodegradability and biocompatibility. PLGA is synthesized by means of ring-opening co-polymerization of two different monomers, the cyclic dimers (1,4-dioxane-2,5-diones) of glycolic acid and lactic acid. Polymers can be synthesized as either random or block copolymers thereby imparting additional polymer properties. Common catalysts used in the preparation of this polymer include tin(II) 2-ethylhexanoate, tin(II) alkoxides, or aluminum isopropoxide. During polymerization, successive monomeric units are linked together in PLGA by ester linkages, thus yielding a linear, aliphatic polyester as a product.

<span class="mw-page-title-main">Polylactic acid</span> Biodegradable polymer

Polylactic acid, also known as poly(lactic acid) or polylactide (PLA), is a thermoplastic polyester with backbone formula (C
3
H
4
O
2
)
n
or [–C(CH
3
)HC(=O)O–]
n
, formally obtained by condensation of lactic acid C(CH
3
)(OH)HCOOH
with loss of water. It can also be prepared by ring-opening polymerization of lactide [–C(CH
3
)HC(=O)O–]
2
, the cyclic dimer of the basic repeating unit.

<span class="mw-page-title-main">Bioplastic</span> Plastics derived from renewable biomass sources

Bioplastics are plastic materials produced from renewable biomass sources, such as vegetable fats and oils, corn starch, straw, woodchips, sawdust, recycled food waste, etc. Some bioplastics are obtained by processing directly from natural biopolymers including polysaccharides and proteins, while others are chemically synthesised from sugar derivatives and lipids from either plants or animals, or biologically generated by fermentation of sugars or lipids. In contrast, common plastics, such as fossil-fuel plastics are derived from petroleum or natural gas.

<span class="mw-page-title-main">Polyester</span> Category of polymers, in which the monomers are joined together by ester links

Polyester is a category of polymers that contain one or two ester linkages in every repeat unit of their main chain. As a specific material, it most commonly refers to a type called polyethylene terephthalate (PET). Polyesters include naturally occurring chemicals, such as in plants and insects, as well as synthetics such as polybutyrate. Natural polyesters and a few synthetic ones are biodegradable, but most synthetic polyesters are not. Synthetic polyesters are used extensively in clothing.

Alpha hydroxy carboxylic acids, or α-hydroxy carboxylic acids (AHAs), are a group of carboxylic acids featuring a hydroxy group located one carbon atom away from the acid group. This structural aspect distinguishes them from beta hydroxy acids, where the functional groups are separated by two carbon atoms. Notable AHAs include glycolic acid, lactic acid, mandelic acid, and citric acid.

<span class="mw-page-title-main">Biodegradable plastic</span> Plastics that can be decomposed by the action of living organisms

Biodegradable plastics are plastics that can be decomposed by the action of living organisms, usually microbes, into water, carbon dioxide, and biomass. Biodegradable plastics are commonly produced with renewable raw materials, micro-organisms, petrochemicals, or combinations of all three.

<span class="mw-page-title-main">3-Hydroxypropionic acid</span> Chemical compound

3-Hydroxypropionic acid is a carboxylic acid, specifically a beta hydroxy acid. It is an acidic viscous liquid with a pKa of 4.9. It is very soluble in water, soluble in ethanol and diethyl ether. Upon distillation, it dehydrates to form acrylic acid, and is occasionally called hydracrylic acid

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<span class="mw-page-title-main">Corbion</span> Biochemicals manufacturer

Corbion N.V., formerly Centrale Suiker Maatschappij (CSM) N.V., is a Dutch food and biochemicals company headquartered in Amsterdam, Netherlands. It produces bioingredient-based foods, chemicals derived from organic acids, and lactic acid based solutions for the food, chemical and pharmaceutical industries. The company was founded on August 21, 1919.

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Parisa Mehrkhodavandi is a Canadian chemist and Professor of Chemistry at the University of British Columbia (UBC). Her research focuses on the design of new catalysts that can effect polymerization of sustainably sourced or biodegradable polymers.

Biofoams are biological or biologically derived foams, making up lightweight and porous cellular solids. A relatively new term, its use in academia began in the 1980s in relation to the scum that formed on activated sludge plants.

References

  1. Sigma Aldrich product page for lactide Retrieved 8th of July 2015
  2. 1 2 3 Römpp Online Chemielexikon Version 3.3 aufgerufen am 25. März 2009
  3. Andreas Künkel; Johannes Becker; Lars Börger; Jens Hamprecht; Sebastian Koltzenburg; Robert Loos; Michael Bernhard Schick; Katharina Schlegel; Carsten Sinkel; Gabriel Skupin; Motonori Yamamoto (2016). "Polymers, Biodegradable". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. pp. 1–29. doi: 10.1002/14356007.n21_n01.pub2 . ISBN   978-3-527-30673-2.
  4. Shuklov, Ivan A.; Jiao, Haijun; Schulze, Joachim; Tietz, Wolfgang; Kühlein, Klaus; Börner, Armin (2011-03-02). "Studies on the epimerization of diastereomeric lactides". Tetrahedron Letters. 52 (9): 1027–1030. doi:10.1016/j.tetlet.2010.12.094. ISSN   0040-4039.
  5. R. Auras; L.-T. Lim; S. E. M. Selke; H. Tsuji (2010). Poly(lactic acid): Synthesis, Structures, Properties, Processing, and Applications. Wiley. ISBN   978-0-470-29366-9.
  6. Odile Dechy-Cabaret; Blanca Martin-Vaca; Didier Bourissou (2004). "Controlled Ring-Opening Polymerization of Lactide and Glycolide". Chem. Rev. 104 (12): 6147–76. doi:10.1021/cr040002s. PMID   15584698.