Manufacturers, biodegradable

Elmendorf tear strength values for these materials after orientation, however, are 6 and 5N/mm in MD and CD, respectively. For unoriented samples, the Elmendorf tear strengths in MD and CD are 4 and 8 N/mm, respectively [27]. The contribution of biaxial orientation in improving the mechanical properties of PLA films is therefore quite evident and this route represents an important tool for manufacturing biodegradable PLA films with good characteristics for several practical applications. 

The energy required to synthesize and manufacture biodegradable plastics is shown in Table 15.1, along with values for high density polyethylene (HOPE) and low density polyethylene (LDPE). PHA biopolymers presently consume similar energy inputs to PEs. New feed stocks for PHA should lower the energy required for their production. 

Certain bacterial species produce polymers of y-hydroxybutyric acid and other hydroxyalkanoic acids as storage polymers. These are biodegradable polymers with some desirable properties for manufacture of biodegradable packaging materials, and considerable effort is being devoted by ICI Ltd. and others to the development of bacterial fermentation processes to produce these polymers at a high molecular weight (66). 

The normal paraffins produced are raw materials for the manufacture of biodegradable detergents, plasticizers, alcohols, and synthetic proteins. Removal of the / -paraffins upgrades gasoline by improving the octane rating. 

Biodegradation studies of starch blends have not been conclusive where a nondegradable synthetic polymer has been the blend component probably biodisiategration would be a better term to describe these polymers. The principal deficiencies of products based on this chemistry, aside from the incomplete biodegradation, are water-sensitivity of manufactured articles, and the balance of this and biodegradation with the starch level ia the product. 

The concept of using biodegradable materials for implants which serve a temporary function is a relatively new one. This concept has gained acceptance as it has been realized that an implanted material does not have to be inert, but can be degraded and/or metabolized in vivo once its function has been accompHshed (12). Resorbable polymers have been utilized successfully in the manufacture of sutures, small bone fixation devices (13), and dmg dehvery systems (qv) (14). 

The popularity of MSA as an electrolyte in electrochemical appHcations has developed as a result of the following unique physical and chemical properties (/) exhibits low corrosivity and is easy to handle, (2) nonoxidizing, (7) manufacturing process yields a high purity acid, (4) exceptional electrical conductivity, (3) high solubiHty of metal salts permits broad appHcations, (6) MSA-based formulations are simpler, (7) biodegradable, and (8) highly stable to heat and electrical current. 

Membrane manufacturers require a standard test to maintain batch-to-batch quality. Few use proteins. Materials selected are ones for which the complications are minimized, the probe is simple, fast, and cheap to detecl , does not readily biodegrade, and gives results, whatever they are, which are reproducible. There is no standardization of these tests within the industry. 

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