23 Apr 2002
EASTAR BIO: a practical solution
The search for plastic material compatible with the environment has taken many paths over the last few decades. The goal was for a material that would last for the useful life of the product, biodegrade, process easily and be affordable. The need for a biodegradable product has evolved into a number of types of products.
Regulatory bodies, such as DIN (Germany), CEN (Europe), JAS (Japan), ASTM
(United States) and ISO (international), have published standards for biodegradability for these products. Although the definitions, test methods, and certification requirements differ in details, they have several features in common:
• In a time frame comparable to kraft paper, a biodegradable polymer within an active composting environment must fragment and/or disintegrate sufficiently to completely pass through specifically sized sieving screens.
• Within an active composting environment, the biodegradable polymer must be reduced to carbon dioxide, water, minerals and biomass in a time frame comparable to kraft paper, usually 6 months.
• Toxic residues or toxic monomers cannot be produced by the composting process.
• The compost containing the biodegraded polymers must support plant growth.
Eastman first introduced a biodegradable material, EASTAR BIO copolyester in the 1990’s. A second generation of EASTAR BIO copolyester is now available, a material with substantial advantages over other forms of biodegradable and compostable materials.
EASTAR BIO copolyester is an aliphatic-aromatic copolyester that performs for the useful life of the manufactured article and then completely biodegrades in a composting environment in six months. Composed of terephtalic acid, adipic acid and butanediol.
This biodegradable thermoplastic resin is manufactured in Europe and is commercially available. It is a Eastman patented product, and the intellectual property surrounding its development covers a number of aliphatic monomers, a wide range of compositions and blends and articles made from the product, like films, fibers and non wovens.
It exhibits a balance of properties particularly of interest to processors and end users of nonwovens, food packaging and other forms of packaging. These properties include superior adhesion, mechanical properties, compatibility with other materials and the ability to blend with a range of fillers from starch to fiber, talc, and sawdust.
Properties
Physical properties of 0.04-mm blown film produced from EASTAR BIO copolyester are compared to those of a typical low-density polyethylene below. Results show it is a soft material, with modulus lower than low-density polyethylene but with superior dart impact strength, specifically at low temperatures. The strength properties may be altered by orientation/higher blow up ratios. Films of this material, although not clear, exhibit good contact clarity.
> Physical Properties of Resin and 0.04-mm Blown Film
Property -- Units -- ASTM Method -- Biodegradable Copolyester -- Autoclave LDPE
MFI, 190°C, 2.16 kg -- grams/10 minutes -- D1238 -- 28 -- 2.5
Density -- grams/cm3 -- D1505 -- 1.22 -- 0.921
Crystalline Peak Melting Point, Tm -- °C -- D3418 -- 108 -- 110
Dart Impact, -- grams -- D1709A
23°C -- . -- . -- 200 -- . -- 75
–18°C -- . -- . -- 85 -- . -- not tested
Film Tensile Properties -- . -- D882 -- MD -- TD -- MD -- TD
Break Stress -- MPa -- . -- 22 -- 20 -- 16
Elongation -- % -- . -- 700 -- 730 -- 300 -- 200
1% Secant Modulus -- MPa -- . -- 100 -- 100 -- 170 -- 180
Barrier properties
While the oxygen permeability of the copolyester is slightly lower than that of polyethylene, water vapor transmission rate is significantly faster. This property makes this copolyester a viable candidate for use in applications such as fresh food packaging and other applications that would benefit from moderately "breathable" characteristics.
Sealing/adhesion characteristics
EASTAR BIO copolyester offers excellent adhesion to a variety of substrates. Strong co extrusion structure
Reader enquiries
Eastman Chemical Company
Fascinatio Boulevard 602-614
2909 VA Capelle a/d IJssel
Netherlands
Notes for editors
Eastman Chemical Company, headquartered in Kingsport, Tennessee, U.S.A., manufactures and markets plastics, chemicals and fibers worldwide with 2000 sales of US $ 5.3 billion. The quality systems of all Eastman® plastics are registered under ISO 9000 except at plants in operation less than one year.
For more information about the company, visit www.eastman.com.
Related images
The search for plastic material compatible with the environment has taken many paths over the last few decades. The goal was for a material that would last for the useful life of the product, biodegrade, process easily and be affordable. The need for a biodegradable product has evolved into a number of types of products.
(Photo ECCPR043E0402 - Easter Bio)
Evolution of the Disintegration of EASTAR BIO Copolyester (0.127-mm Film). A number of C14 radiolabeled CO2 recovery studies confirm the ability of EASTAR BIO copolyester to undergo the 90% minimum degradation required to comply with DIN certification requirements.
Editorial enquiries
Hans Boots
Eastman Specialty Plastics
Nancy van Heesewijk
EMG