Polylactic Acid Properties, Production, Price, Market and Uses

Poly lactic acid (PLA) is kind of biodegradable thermoplastic derived from renewable sources including corn starch (majorly in U.S & Canada), cassava roots, chips, starch (in Asia) or even from sugarcane (in the rest of the world).

 

Polylactic Acid Filament Coil


What is Polylactic Acid (PLA)?

PLA material is different from the commonly available form of thermoplastic polymer materials. It is primarily derived from renewable resources like corn starch or sugar cane.

Mostly plastics are derived through a common process termed as polymerization utilizing the non-renewable sources of energy. However, PLA plastic is a form of bioplastic derived from biomass.

It is a kind of biodegradable plastic with the characteristics similar to all other polymers such as Polypropylene (PP), Polyethylene terephthalate or Acrylonitrile Butadiene Styrene (ABS)

Poly lactic acid is applicable for a variety of uses including the production of plastic films, plastic bottles and medical devices (biodegradable in nature). It is even used 3D printing along with producing objects to hold hot liquids (e.g. cups).

Different Types of Polylactic acid

There are many types of polylactic acid available including Racemic PLLA (Poly-L-lactic Acid), Regular PLLA (Poly-L-lactic Acid), PDLA (Poly-D-lactic Acid), and PDLLA (Poly-DL-lactic Acid).

Each of them is slightly different in their characteristics but are produced in a similar way from renewable sources (lactic acid).


History of Polylactic Acid

PLA was first discovered by Wallace Carothers (who also invented nylon) in 1920. He was aiming to produce an environmentally-friendly plastic for DuPont. In initial days the commercial use of PLA material was very costly.

Further, in 1989 Dr. Patrick R. Gruber along with his wife Sally, discovered the process of producing this material by corn on his stove at home, which reduced the manufacturing cost.

Nowadays this is the most commonly used environment-friendly thermoplastic at the global level.


How is Polylactic Acid Produced?

This material is produced by usage of two basic monomers which are lactic acid and lactide (cyclic de-ester). Two different processes are involved in producing PLA are condensation and polymerization.

The most commonly used process is polymerization process. It is termed as ring-opening polymerization of lactide with various metal catalysts (tin octane) in solution, melt form or even as suspension. This process results in metal catalyst combining with lactide to form larger pla molecules.

The condensation process is very similar to the polymerization process. The principal difference in both the processes is temperature during the process and the by-products (condensates) released after the reaction.

This process is carried out at less than 200°C, as above this temperature entropically favored lactide is generated. At initial level of the process lactic acid is first oligomerized to PLA oligomers. Afterwards, poly-condensation is done in melt or solution where short oligomers combine and produce high molecular weight PLA.

Feedstock Efficiency Score for PLA

Feedstock Efficiency Score for Polylactic Acid

Feedstock efficiency here describes the conversion ratio of feedstock weight to plastic polymer weight & the combination of theoretical efficiency with production efficiency.

Basically, a variety of bioplastics produced require a different amount of feedstock in their production process.

As the graph depicts, that PLA is one of the most efficient biopolymer yielding 1kg of polymer for 1.6 kg of the fermented amount of sugar feedstock. As compared to this material other biopolymers require 2-3 times more feedstock for production.

Polylactic Acid Share in Bioplastic

Bioplastics consist of a small percentage of plastics that are produced annually. The demand of bioplastics is increasing along with the production capacity. The total production capacity of bioplastic in 2017 was 2.05 million tonnes.

The production capacity of bio-based, biodegradable plastics is increasing due to the availability of new kinds of raw material. PLA is one of the major raw materials used in the production of the bioplastics.

PLA occupies a prominent share in the raw material used for the production of bio-based, biodegradable plastics. It occupies a share of 10.3% of the raw material used for bioplastics production. It is being used as a replacement of traditional polymer such Polypropylene, Polystyrene, and ABS because of its unique properties. PLA polymer has excellent barrier properties.

Leading Manufacturers of Polylactic Acid

anufacturer of Polylactic Acid

NatureWorks depicts the highest production capacity among all other leading manufacturers worth of 150 kt/a, which is followed by Pyramid technologies with the yearly production capacity of 60 kt/a for the year 2014.

The other two following companies had the almost similar production capacity of 50 kt/a.

The production capacity of these companies is rapidly increasing in accordance with the increased demand for consumption on yearly basis.


Properties of Polylactic Acid

PLA plastic biodegradable nature and suiting optical, physical and chemical properties prove it to be an ideal choice of material for a number of applications including dyeing for textiles, packaging, medical devices (stents & sutures) even for diapers and many others.

Basic Properties Include:

  • High mechanical strength
  • Low toxic level
  • Good Barrier properties (moisture, heat etc.)
  • High mechanical resistance
  • Good and smooth appearance
  • Resistant to chemicals
  • UV resistant
  • Low flammability & smoke formation

Physical Properties of Poly Lactic Acid:

  • PLA Density- 1.210–1.430 g·cm−3 [1]
  • Melting Point- 150 to 160 °C (302 to 320 °F; 423 to 433 K)[1]
  • Specific Gravity- 1.27
  • Glass Transition Temperature- 55°C

Mechanical Properties of Poly Lactic Acid:

  • Tensile Strength- 59MPa
  • Flexural Strength- 106MPa
  • Elongation at break- 7.0%
  • Rockwell Hardness- 88HR

Polylactic Acid Trading Price

 


Global Trade of PLA

Trade Balance of PLA

Global Trade Balance of Polylactic Acid

PLA global trade balance is negative. Since 2011 the import of PLA is more than the exports. The import of PLA in 2016 was worth of US$ 204.79mn while export was US$ 181.55mn.

The exports have been increasing from 2011 onwards while an import shows a fluctuating trend.

Top 10 Countries Exporting PLA

World Top 10 Countries Exporting Polylactic Acid

The United States is the largest exporter of PLA in 2016. It exported PLA worth of US$ 116.47mn. It was followed by Netherlands which exported polymer worth of US$ 41.82mn.

As seen the United States is exporting the major share PLA while other remaining countries are exporting very small quantity of PLA.

Top 10 Countries Importing PLA

World Top 10 Countries Importing Polylactic Acid

Taiwan is the largest importer of PLA in 2016. It imported PLA worth of US$ 37mn. The second largest importer of PLA was Netherlands worth of US$ 32.8mn. Netherlands is not only second largest importer globally but also is exporting a large quantity of the PLA.

The demand of PLA is increasing because as there is favorable regulation world-wide for bio-based materials.


World Polylactic Acid Market Forecast

Global Polylactic Acid Industry Forecast

 

The global poly lactic acid market is expected to become more than US$ 5bn by 2020.

PLA acid market is expected to show a significant amount of growth in coming years owing to its increased usage in packaging, personal care, and textiles.

Market Segmentation – The market can be segmented on the basis of end-user industry and Region.

On the basis of End-User industry- It can be classified into Packaging, Agriculture, Textile, Biomedical, Electronic and other consumer goods industries.

On the basis of Region- It can be segmented into North America, Latin America, Western Europe, Eastern Europe, Asia Pacific, Japan, and Middle East & Africa.

Market Drivers- Factors majorly driving the global market demand are:

  • Increases usage of PLA in personal care products (creams, shampoos and other body care products).
  • Growing consumer awareness about sustainability, recyclability and green packaging is expected to drive the market.
  • A government incentive to manufacturers for producing this material.
  • Easy availability of raw materials.

Market Restraints- Factors hampering the growth of the market are:

  • volatility in raw material prices  (corn, sugar and tapioca starch)
  • Agricultural fiber alternatives
  • Need for industrial composting units
  • High price as compared to other polymers.

Opportunities & Rising demand in various industries

  • Easily blends with other materials.
  • Produced from biomass which is environment-friendly form of plastic
  • Rising adoption of PLA in end-user industries.

Different end user industries have witnessed a rise in demand for PLA plastic due to its unique physical & mechanical properties. The major industries include:

  • Textile industry- This is one of the important sectors with high growth and penetration rate of poly lactic acid as it offers smooth 7 pleasant fabrics.

Properties like smooth appearance, low flammability, and good moisture barrier facilitate the growth of this material in the forecasted period.

  • Pharmaceutical Industry- Growing use of this material in medicines and medical devices (stents and sutures) is also boosting the global market demand (especially in The United States).

Huge Pharmaceutical brands like Johnson & Johnson, Unilever, and Procter & Gamble are using pla plastics and promoting the demand.

  • Cosmetics Industry- Increased usage of this plastic in cosmetic products and their packaging is fueling the market demand. It is being widely used in cosmetics such as creams, shampoos, conditioners, and lotions etc.
  • Packaging industry- Packaging industry primarily for food and beverages have shifted to toward environment-friendly products (green packaging), which drives the market demand.
  • Bio-plastic industry- It has become on the most prominent form of bioplastic material being used commonly.

It’s advantaged over other forms of bioplastics like high moisture & grease resistance, odor& flavor characteristics and clarity help to stimulate the market.

Market Key Players- The major players in the global market are NatureWorks LLC, Corbion Purac BV, Mitsui Chemicals, Inc., Hitachi, Ltd., BASF SE, Braskem along with others.

Regional Outlook- Europe was the largest market for poly lactic acid and is expected to maintain its position in the coming years (2017-2025) primarily, due to regulatory norms on the usage of bio-plastic in various end-segment markets.

These strict government norms and regulations toward usage of bio-plastics instead of plastic synthesized from petroleum for various end segment industries including food & beverages, cosmetics, and pharmaceuticals has boosted the demand in this region.

North America in terms of consumption has been the dominant market due to increased usage of personal care products, rising pharmaceutical and fragrance industries in this region.

It is followed by Asian Pacific regions with high revenue growth from manufacturing base of personal care products from China, India & Japan. Developing countries like China.

In developing countries like India and China technological advancements and high consumer demand are essential factors for increased use of PLA in industries including packaging, textile, and electronics.

Low production cost along with favorable government initiatives in the production of this plastic material is driving the market growth of these regions.


Applications and Uses of Polylactic Acid

PLA has the potential for a wide range of application ranging from being used in the packaging sector, textile, and electronics to pharmaceuticals.

Poly lactic acid application can be segmented into two broad categories including plastic applications and fiber applications.

Poly (lactic) Acid Plastic Applications

PLA plastic is used in three different forms- Rigid thermoforms, biaxially oriented films and bottles for a variety of applications.  These applications are as follows:

  • As rigid thermoforms pla plastic are applicable for following uses:
  • Meat trays and opaque dairy (yogurt containers)
  • Bakery, fresh herb, and candy containers
  • Disposable articles (for consumables) and cold drink cups
  • Consumer displays and electronics packaging
  • Clear fresh fruit and vegetable clamshells
  • As biaxially oriented films pla plastics are used for:
  • Envelop and display carton windows
  • Candy twist and flow & floral wraps
  • Lamination films
  • Tapes, stand-up pouches & die cut labels
  • Cake mix, cereal & bread bags
  • Lidding stock along with shrink sleeves.
  • PLA plastics are used to manufacture the following kind of bottles:
  • Short-shelf life milk bottles
  • Bottles used for edible oils
  • Bottled water

Poly (lactic) acid fiber applications

The physical properties of this material make it an ideal choice for the textile industry to be used in form of fibers. As fibers it has following application in different segments:

  • Apparel- Use for casual (sports-), active, and underwear fashion item
  • Nonwovens- In wipes, hygiene products, diapers, shoe liners, automotive head and door liners
  • Industrial Carpets- For residential/institutional broadloom and carpet tiles. Even for agricultural and geo-textiles.
  • Fiber Fill- Use widely in pillows, comforters, mattresses, Duvets, and furniture

End-Segment Applications

PLA material is a commonly used form of bioplastic in end segment consumer market these days. Due to shift in customer preferences towards more use of environment-friendly products (bio-plastics) demand for these materials is rising continuously.

It has successfully replaced many forms of thermoplastics used in different sectors because of its unique qualities, better performance, and easy degradation.

These sectors comprise of packaging (food & beverages), building (roofing. tiling & construction materials), agriculture (mulch films), transport (automotive parts), furniture (tables, drawers, cabins etc), electronic appliances (computers, CD covers etc) and many household products (cosmetics, diapers, carpets etc).

PLA Food Packaging & Nanotechnology

Nanotechnology has increased its application in food industry. Nanoparticles like micelles, liposomes, nanoemulsions and biopolymeric are used to ensure the safety of packaged food products.

Using nanotechnology in food packaging results in improved packaging performance such as:

  • Better resistance towards gas, moisture & UV radiation.
  • Increased mechanical strength along with decreased weight.
  • Increase heat resistance & flame retardancy.
  • Intelligent packaging which helps to monitor product condition during transportation.

Various kinds of nanocomposites are involved in this process. These composites are primary particles filled with polymers. PLA is widely used form of polymer for these nanocomposites in food packaging

PLA Nanocomposites

These composites are a combination of PLA material & montmorillonite layered silicate that result in better food packaging material with enhanced barrier properties.

Advantages and Disadvantages of Polylactic Acid

PLA plastic materials have a number of advantages over their competing polymers which make them preferred choice of manufacturers among all. These advantages are:

  • More environment-friendly in nature.
  • Shinier and smoother appearance with a glossy finish.
  • Emits sweet smell during the printing process.
  • No harmful fumes are produced in the production of the final good.
  • Can be easily printed even on the cold surface.

Though it has unique properties which make this material suitable for a number of applications (Primarily in en-segment industries) but, still it has some disadvantages which are:

  • As compared to other polymers it has relatively low glass temperature.
  • It is a little more brittle in nature primarily for 3D prototyping.
  • Can be deformed because of heat.


PLA V/s ABS

These two are the most common kind of thermoplastics used widely as desktop printing material. Both of them are soft and can be easily shaped by melting and cooling.

Though these two polymers share common properties and applications, there are some major differences in their formation, properties and recycling which are discussed below:

Definition

Acrylonitrile Butadiene Styrene (ABS) is a recognized thermoplastic used globally, majorly in the injection molding industry. It’s some of the applications are being used in LEGO, Automotive parts and electronics etc.

Polylactic Acid (PLA) is a biodegradable form of thermoplastic derived from renewable sources like corn starch or sugarcane. It is a recognized bioplastic in the industry with uses ranging from cups to medical implants.

Properties

PropertiesABSPLA
Tensile Strength27MPa37MPa
Density1.0 – 1.4 g/cm31.3 g/cm3
Glass Transition Temperature105°C60°C
Elongation35-50%6%
Melting PointN/A (amorphous)173°C
BiodegradableNoYes

 

Application Suitability

Acrylonitrile Butadiene Styrene is best suited for applications of products which require strength, ductility, durability and thermal stability. (more prone towards wrapping).

Poly (lactic) acid is more suited for 3D printing where aesthetics are given preference. As it posses low printing temperature thus, it becomes easier to print with smooth finishing.



PLA Biodegradability, Degradability and Recyclability

Biodegradation

Biodegradable plastic is a kind of plastic which degrades due to the action of naturally occurring microorganisms such as bacteria, fungi, and algae.

Almost all kind of plastics including Polypropylene (PP), Polyvinyl chloride (PVC) Polyethylene (PE) and others are resistant towards microbial attack but, there are certain bioplastics like PLA which degrade by micro-organisms.

Degradation

Degradation of this material was first studied in animal & human bodies (implants, surgical sutures & drug delivery materials).

It is initially degraded by hydrolysis and further, the oligomers formed are metabolized by cells. Materials to be degraded are first hydrolyzed at elevated temperatures of about 58°C to reduce their molecular weight.

Enzymes such as Amycolatopsis & Saccharotrix are used commonly to initiate the process of degradation of poly lactic acid.

Recycling

Currently, the Society of Plastic Industry (SPI) with the resin identification code as 7 (“others”) is applicable to this material. These plastics are recycled to monomers through thermal depolymerization or hydrolysis instead of mechanical recycling to avoid contaminants.

A recycled form of monomer can be further used for manufacturing virgin poly lactic acid with no change in original properties.


Is Polylactic Acid Toxic?

It is a biodegradable form of thermoplastic, often used in packaging of food & beverages, medical implants (which biodegrade within the body).

Like other plastic materials, it also posses the potential to be toxic in nature if inhaled or absorbed in the skin, eyes in vapor and liquid form (majorly during the manufacturing process).

Thus, they are needed to be handled carefully especially when it is in molten form during the production process.