Ecoflex

Ecoflex can be used for the manufacture of biowaste bags and several films applications (i.e., packaging, mulching, hygiene products and household applications). 

Ecoflex meets the requirements of Deutsche Institut fur Norms (DIN) V 54900 [67] as a compostable material and is certified by DIN CERTCO (Compostable), EN 13432, ASTM D6400 and the Japanese standard GreenPla [68]. 

Trade name Ecoflex F BX 7011 Eastar Bio GP Biomax EnPol G8000 W 

Ecoflex is based on a copolyester from terephthalic acid, adipic acid and 1,4-butanediol. The content of terephthalic acid in the polymer is approximately 42-45 mol% (with regard to the dicarboxylic monomers). Modifications of the basic copolyester lead to a flexible material which is especially suitable for film applications. A down gauging to 10 pm films can be achieved [89] according to the producer. 

The following (potential) applications for Ecoflex are announced by BASF AG  

Ecoflex meets the requirements of DIN V 54000 [31] as compostable material and is certified by DIN CERTCO (Ecoflex max 120 pm films, Reg. No. 7W0011 Ecoflex CL max 15% cellulose, max. 120 pm films Reg. No. 7W0020 Ecoflex TK max. 45% talc, max. 120 pm films, Reg. No. 7W0019). 

Like Ecoflex, the Eastman product is based on a copolyester composed of terephthalic acid, adipic acid and 1,4-butanediol, but due to some special modification the material properties are different. 

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Copolyester of terephthalic acid, Ecoflex BASF Environmental Petrochemistry... 

BAK, Bioceta, Biomax, Bionelle, Biopol, Cortec, CPLA, Easter Bio, Ecoflex, Mater-Bi, Metabolix, Nature Works PLA, Nodax, PEC (polyester carbonate), PLA, Sky Green BDP... 

Ecoflex and Ecovio Biodegradable, Performance-Enabling Plastics... 

Ecoflex A Completely Biodegradable Aliphatic-Aromatic Polyester. 104... 

Outlook for base s Biodegradable Polymers Ecoflex and Ecovio . 134... 

Biodegradable plastics have been used on an industrial scale since the end of the 1990s when BASF launched Ecoflex . This is a fossil-based, man-made polyester but yet is completely biodegradable due to its chemical structure. This structure is also the reason why Ecoflex combines excellent mechanical properties with the good processability of synthetic thermoplastics. Ecoflex is the preferred blend partner for bio-based and biodegradable polymers, which typically do not exhibit good mechanics and processability for film applications by themselves. Ecoflex therefore is a synthetic polymer that enables the extensive use of renewable raw materials (e.g., starch). 

To prove the ultimate biodegradability of a biodegradable polymer and that there is no adverse effect on the user or the environment, as well as to successfully market a plastic material as biodegradable, there are international standards in place according to which these materials can be certified. Both Ecoflex and Ecovio are certified worldwide as compostable and are approved for contact with food. 

Ecoflex F, the original Ecoflex grade, is a completely fossil-based ahphatic-aromatic copolyester produced by BASF (see Sect. 4). It is synthesized from 1,4-butanediol, adipic acid and terephthalic acid, and is a poly(butylene adipate-co-butylene terephthalate) (PBAT). 

Biodegradable products are designed for applications where the functional property of biodegradability is a sustainable feature and is of value to the customer. The products show their potential at the end-of-use phase. The preferred end-of-life option for biodegradable products made of Ecoflex is composting. To make sure... 

Table 1 Fragments of Ecoflex after degradation with isolated pure strain (Tests 1-3) and with pure and mixed cultures from compost...

Fig. 1 Controlled composting test of Ecoflex yields >90% conversion to CO2 after 80 days...

CO2, a blank compost inoculum without an additional carbon source (polymer sample) is simultaneously tested under the same conditions. The CO2 content of the exhaust air of both vessels is compared. After subtracting the CO2 evolution of the blank inoculum, the CO2 evolution related to the test polymer is monitored and plotted as a biodegradation curve (see Fig. 1). Finally, the activity of the compost inoculum in the controlled composting test is validated using a cellulose reference instead of the polymer. In Fig. 1, the biodegradation curve of Ecoflex is depicted. After 80 days, 90% of the theoretical CO2 evolution is reached. Thus, Ecoflex is ultimately biodegradable according to the ISO standard for compostable polymers (ISO 17088), which requires 90% of the theoretical CO2 evolution within 180 days. 

Testing of Ecoflex was carried out in accordance with DIN 38412 Part 30. In this test, the pollutant-dependent immobilization of daphnia in solutions of different concentrations (series of dilutions) is used. The control solution contains microorganisms that are known to biodegrade the test polymer. The stock solution at the end of the test also contains the degradation intermediates of Ecoflex . 

Table 4 Toxicological tests performed with Ecoflex K.O. Siegenthaler et al. )... 

Mixture of reference soil and 25% compost with addition of Ecoflex after 12 weeks composting. 

The eco-toxicity of composted Ecoflex was investigated in an earthworm acute toxicity test following the OECD guideline 207 (reference). In this test, earthworms... 

There was no mortality in any of the treatments after 7 and 14 days. In the control and treated soil a significant increase of biomass compared to the start of the test was observed. In conclusion, soil mixtures containing compost exposed to Ecoflex had no adverse effects on earthworm survival and biomass development. 

The potential of Ecoflex (powder) to cause acute dermal irritation or corrosion was assessed by a single topical application of the test substance to the intact skin of rabbits according to OECD guideline 404. After removal of the patch, the application area was washed off and cutaneous reactions were assessed for 72 h. No cutaneous reactions were observed. Hence, Ecoflex (powder) is not irritating to skin. 

Ecoflex (powder) was tested for its sensitizing effect on the skin of the guinea pig in the modified Buehler test according to OECD guideline 406. Skin-sensitizing effects were not observed in these animal studies. 

Ecoflex (powder) was tested for its mutagenic potential on the basis of its ability to induce point mutations in several bacterial strains Salmonella typhimurium and Escherichia coll) in a reverse mutation assay (Ames test), according to OECD guideline 471. Results revealed that the polyester is not mutagenic to bacteria. 

At the end of the 1990s, BASF commercialized Ecoflex F, a completely biodegradable statistical copolyester based on the fossil monomers 1,4-butanediol (BDO), adipic acid and terephthalic acid (see Fig. 3). Ecoflex F combines the good biodegradability known from aliphatic polyesters with the good mechanical properties of aromatic polyesters. 

Ecoflex F was designed to be a strong and flexible material with mechanical properties similar to PE. The films are tear-resistant and flexible, as well as resistant to fluctuations in water and humidity. Ecoflex F is a thermoplastic and can be melt-processed on standard polyolefin equipment (see Sect. 5). It is mainly used in film applications. The very high toughness and failure energy represent product characteristics of Ecoflex F that significantly exceed the respective properties of PE films. 

Ecoflex F is sold by BASF to converters that produce biodegradable blends with it and finally manufacture the film products for end use (see Sect. 4.2). BASF also uses it for the production of Ecovio F (see Sect. 4.2.2). 

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