Polylactic acid chemical properties

Lactic acid is an important chemical that has wide applications in food, pharmaceutical, cosmetic, and chemical industries. There are increasing interests in production of lactate esters and biodegradable polylactic acid (PLA) from lactic acid. Lactate esters are a relatively new family of solvents with specific properties. They are considered safe and are biodegradable (1). In many situations they can replace toxic solvents. Their functions vary from that of intermediates in chemical reactions to solvents in ink formulations and cleaning applications (2). PLA has been widely used in medical implants, sutures, and drug-delivery systems because of its capacity to dissolve over time (3-5). PLA also can be used in products such as plant pots, disposable diapers, and textile fabrics. 

In recognition of the superior properties and the huge potential market of polylactic acid, Cargill Inc. and The Dow Chemical Company started a joint venture Cargill Dow LLC to produce lactic acid using... 

Synthetic polymers commonly used in numerous biomedical devices offer the distinct advantage of high level of control over the chemical properties of the polymer. As a scaffold for adipose tissue engineering, polylactic acid, polyglycolic acid, and copolymers incorporating both have been widely investigated due to their ability to degrade over... 

Natural polymers such as starch and protein are potential alternatives to petroleum-based polymers for a number of applications. Unfortunately, their high solubility in water limit their use for water sensitive applications. To solve this problem thermoplastic starches have been laminated using water-resistant, biodegradable polymers. For example, polylactic acid and P(3HB-co-3HV) were utilised as the outer layers of the stratified polyester/PWS (plasticized wheat starch)/polyester film strucmre in order to improve the mechanical properties and water resistance of PWS which made it useful for food packaging and disposable articles [65]. Moreover, improved physic-chemical interactions between P(3HB-CO-3HV) and wheat straw fibres were achieved with high temperature treatment. It resulted in increased P(3HB-co-3HV) crystallization, increased Young s moduli and lowered values of stress and strain to break than the neat matrix of P(3HB-co-3HV). There was no difference in the biodegradation rate of the polymer [66]. 

Ajioka, M., Enomoto, E., Suzuki, K. and Yamaguchi, A. (1995) Basic properties of polylactic acid produced by the direct condensation polymerization of lactic acid. Bulletin of the Chemical Society of Japan, 68,2125-2131. 

Biodegradation indicates degradation of a polymer in natural environment. This implies loss of mechanical properties, changing in the chemical structure, and into other eco-friendly compounds (Jamshidian et al. 2010). Degradable polymers from natural sources (such as lignin, cellulose acetate, starch, polylactic acid (PLA), polyhydroxylaUcanoates, polyhydroxylbutyrate (PHB)), and some synthetic sources (polyvinyl alcohol, modified polyolefins, etc.) are classified as biopolymers (John and Thomas 2008). It is noticeable that the nanocomposite from nonrenewable synthetic sources is neither wholly degradable nor renewable. 

The second stage of transformation will likely result in synthesis of new bio-based plastics such as polyhydroxy alkanoates and polylactic acid. Such plastics are chemically and structurally different from conventional plastics, but will be similar to the latter in terms of their properties, making them potential alternatives to both petroleum and bio-derived conventional plastics. Both the first- and second-generation transformations are, however, likely to generate concerns about the use of food-based precursors for synthesizing plastics, given that they will divert crucial food resources meant for human and animal consumption. 

Leo Manzer 1 think there is an opportunity to do both things. Certainly looking at new chemical routes to the top 10 or 15 chemicals is fine. I think the other way to go is look at the properties that we are after and go after alternates—polylactic acid, for example, instead of styrene. Instead of building these big massive plants that consume lots of energy and fossil fuels, find some other way to get the desired properties from a different product altogether. 

Polymers Polyglycolic acid, polylactic acid, poly(orthoesters), polyethylene glycol, poly-lactic-co-glycohc acid, polyurethane, and poly-e-caprolactone Tunable properties (physical, chemical, and biological) to match the requirements of specific applications Ulery et al. (2011), Maitz (2015), and Rashidi et al. (2014)... 

Polylactic (and polyglycoUc) acids are mainly produced by chemical polymerisation of lactic acid (and glycoUc) acid obtained by Lactobacillus fermentation. Commercial applications of polylactic acid materials are growing up very rapidly under the trade marks of Ecopla ifom CargilFDow Chemical or Lacea Ifom Mitsui. Synthetic biodegradable polyesters are produced by the major chemical companies such as Basf (Ecoflex ), Eastman (Ecostar ), Showa Denco (Bionolle ) and Solvay. Thermoplastic biodegradable materials are sometimes formulated with paper, fibres or fibrous materials to form composites with optimised properties. 

Polylactic acid (PLA) is a biodegradable and bioabsorbable natural polyester with favorable bioconpatibility and suitable bulk properties. This polymer has been used as a bioabsorbable material in the medical and pharmaceutical fields. However, the surface properties of PLA are not easily altered because its high crystallinity with no chemically modifiable side-chain groups, besides its hydrophobic behavior which makes it not appropriate for direct contacting with polar hydrophilic materials or biological environments. 

We felt that the physicochemical properties of the polymer might therefore be manipulated to alter the cell shape and thus the cell physiology. We next studied the effects of polymers of different physical and chemical configuration on cell attachment, viability and performance of differentiated function. The ability of the hepatocyte to maintain differentiated function was assessed by Ae rate of albumin secretion. We found that a suitable polymer was an uncoated 85 15 combination of polylactic/polyglycolic acid. This suggested to us that a... 

Anaerobic fermentation of maize carbohydrate can also be modified to produce high yields of the 3-carbon molecule lactic acid [362]. Esterification with ethanol produces ethyl lactate which has good solvent properties and can be used as a chemical intermediate. Conversion of lactate to the lactide dimer produces the intermediate for polylactate resin manufacture. 

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