Biomax

Producer/patents DuPont Polyester Resins Intermediates, USA [96-99] 

Biomax is, according to the producer, a standard PET with addition of special monomers to allow degradation to take place. Comparable to PLA, the degradation mechanism is described as an initial attack of water to the special monomers which are sensitive to hydrolysis. Oligomers formed by this first abiotic degradation step can be transported into microbial cells and there be metabolised (Biomax is claimed to be (hydro/ biodegradable). 

However, although it seems that Biomax sufficiently disintegrates under composting conditions [100], the final metabolisation of the material in a reasonable time scale is still under discussion. The producer itself admits that Biomax in the current formulation (June 2000) does not degrade fast enough to meet the accepted standards and thus, will improve the material with regard to its biodegradability [101]. 

The producers stress the superior harrier properties of the polyester compared to other biodegradable materials. 

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Copolyester of terephthalic acid, Biomax DuPont Environmental Petrochemistry... 

Figure 17.2 Applications of DuPonT BIOMAX hydrobiodegradable polyester -film, rigid containers, fibers, injection molded parts and paper coatings. Photograph reproduced by permission of DuPonT1...

BioMAX is a registered Trademark of El DuPonT de Nemours and Company. Earthshell Corporation and Earthshell Packaging are registered Trademarks of Earthshell Corporation. 

Copolyesters (such as BIOMAX ) which combine aromatic esters with aliphatic esters or other polymer units (e.g. ethers and amides) provide the opportunity to adjust and control the degradation rates. These added degrees of freedom on polymer composition provide the opportunity to rebalance the polymer to more specifically match application performance in physical properties, while still maintaining the ability to adjust the copolyesters to complement the degradation of natural products for the production of methane or humic substances. Since application performance requirements and application specific environmental factors and degradation expectations vary broadly, copolyesters are, and will continue to be, an important class of degradable polyesters. 

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

Estimate and quantify macroscopically the hybridization signal on BIOMAX (Kodak, Rochester, NY) films after 5 days of exposure. 

Air-dry the slide and expose it to low-energy X-ray film (Kodak Biomax MR film) or Phosphorimager (Molecular Dynamics). 

If necessary, the vector can be concentrated, and desalted or buffer exchanged in a Biomax 100 K concentrator (Millipore) by three cycles of centrifugation. In each cycle the virus is concentrated to 1 ml following the addition of 10 ml of Lactated Ringer s or 1 x PBS. The virus is stored at -80 °C in lactated Ringer s or 1 x PBS. 

DuPont s Biomax is used in a number of specialty packaging applications, injection-moulded parts, coatings for paper, thermoformed cups and trays, and films because of its superior barrier properties. DuPont has targeted fast-food disposable packaging, as well as yard-waste bags, diaper backing, agricultural film, flowerpots, and bottles, for particular development. 

The price of synthetic biodegradable polymers has come down a little during the last three years. In 2003, for example, the average price of Eastar Bio and BASF s Ecoflex was around 3.5-4.0 per kg. In 2005, the average cost of an aliphatic aromatic polyester biopolymer was between 2.75-3.65 per kg. The more specialised polymers, such as DuPont s Biomax, cost as much as 5-6 per kg. Polycaprolactones cost between 4-7 per kg. Synthetic biodegradable polymer prices are expected to fall further over time as production volumes increase and unit costs fall further. 

DuPont offers a family of biodegradable polymers based on polyethylene terephthalate (PET) technology known commercially as Biomax. Proprietary monomers are incorporated into the polymer, creating sites that are susceptible to hydrolysis. At elevated temperatures, the large polymer molecules are cleaved by moisture into smaller molecules, which are then consumed by naturally occurring microbes and converted to carbon dioxide, water and biomass. Biomax can be recycled, incinerated or landfilled, but is designed specifically for disposal by composting. 

Wrap each membrane, backed with precut support paper, in Saran wrap (do not substitute with another brand), and expose to Kodak Biomax X-ray film for 24-48 h at -70°C with a Biomax MS enhancing screen. Analyze filters on a beta scanner (Instantlmager , Packard Instruments) for approx 1-2 h. 

Methods of quantitation other than the listed beta scanner and the use of Biomax film can be used (e.g., Kodak X-OMAT AR film, AMBIS beta scanner, phosphorimager, densitometric scans on films, and so on). However, the authors have found that these items are, by far, the most sensitive and efficient tools for quantitation of HBV DNA in this assay system. 

In 1996, DuPont commercialized Biomax biodegradable PET that contains three proprietary ahphatic monomer units to introduce sites susceptible to hydrolysis. The broken down PET chains are biodegraded by namrally occurring microorganisms. 

Figure 9.4 and Table 9.1 respectively show the chemical structure and the properties of these materials. Most commonly used is poly(butylene adipate-co-terephtalate) (PBAT). BASF, DuPont and Zhejiang Hangzhou Xinfu (China) manufacture and market these aromatic polyesters, under the respective brands Ecoflex , Biomax and Biocosafe . Biomax has a high terephthalic acid content, which modifies some of its properties such as the melting temperature (200°C). According to Muller et al., an increase in terephthalic acid content tends to decrease the rate of biodegradation into compost [MUL 97]. 

Compared with totally aliphatic copolyesters, aromatic copolyesters are often based on terephthalic diacid. BASF markets a product, Ecoflex, which is a copolyester of butanediol, adipic acid, and dimethyl terephthalate. Eastman s Eastar Bio Copolyester is similar aliphatic/aromatic copolyester. DuPont markets a modified PET known as Biomax [Chauhan, 2012]. 

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