Standards biodegradable polymers

All liposphere formulations prepared remained stable during the 3-month period of the study, and no phase separation or appearance of aggregates were observed. The difference between polymeric lipospheres and the standard liposphere formulations is the composition of the internal core of the particles. Standard lipospheres, such as those previously described, consist of a solid hydrophobic fat core composed of neutral fats like tristearin, whereas, in the polymeric lipospheres, biodegradable polymers such as polylactide or polycaprolactone were substituted for the triglycerides. Both types of lipospheres are thought to be stabilized by one layer of phospholipid molecules embedded in their surface. 

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. 

Table 3 Logos of biodegradable polymers according to the standards [7]...

Product development and improvement has a crucial role to play in the further development of the biodegradable polymers market. These include development of more reliable and lower cost raw materials for manufacture of biodegradable polymers, improvement in performance properties vis-a-vis standard thermoplastics, improvement in processing performance and development of new polymers and blends. 

Biodegradable polymers can make a positive contribution to the conservation of the world s natural resources and protection of the environment. However, their market potential will only be fulfilled if the required framework conditions are put in place to ensure the necessary investment in technology and production capacity. Framework conditions refer to the development of industry standards and regulatory systems, certification and certification systems that are designed to encourage biodegradable polymer market development. 

During the period 2000 to 2005, world consumption of synthetic biodegradable polymers has increased from 3,900 tonnes to 14,000 tonnes. In 2010, world consumption of synthetic biopolymers is projected to reach 32,800 tonnes. This represents a compound annual growth rate of 18.6% during the period 2005-2010. These forecasts assume that producers are successful in lowering the cost of production and that the price differential between synthetic biopolymers and standard thermoplastics continue to narrow. 

Biodegradable polymers are similar in terms of their chemical structure to conventional thermoplastics such as polyethylene, polypropylene and polystyrene. They can be processed using standard polymer processing methods such as film extrusion, injection moulding and blow moulding. 

Table 1. General definitions of a biodegradable polymer (or plastic) proposed by Standard Authorities ...

Narayan R (1992) Development of standards for degradable plastics by ASTM Subcommittee D-20.96 on environmentally degradable plastics. In Vert M, Feijen J, Albertsson A, Scott G, Chiellini E (eds) Biodegradable Polymers and Plastics. The Royal Society of Chemistry, Cambridge, pp 176-190... 

Polyamides and polyesteramides are more recent arrivals to the commercial biodegradable polymer field. Copolymers of either glycine or serine with e-aminocaproic acid are biodegradable. For example, biodegradable polyaspartic acid was synthesized (95% yield) at low cost [Koskan, 1992]. A copolymer of butylene-adipate and e-caprolactam was recently introduced by Bayer as BAK 1095. The material has T = 125°C, density of 1070 kg/m, tensile modulus of 180 MPa, maximum strain at break of 400%, tensile stress at break of 25 MPa, and it fully degrades in 300 days under the ASTM standard conditions. 

K. J. Seal, Test Methods and Standards for Biodegradable standards in Chemistry and Technology of Biodegradable Polymers, G. J. L. Griffin Ed., Blackie Academic Professional Glasgow, UK, pp. 116-134 (1994). 

Seal, K.J., 1994, Test mediods and standards Rubiod radable plastics. In Griffin, GJ.L. (ed., Chemistry and Technology of biodegradable polymers. Blackie Academic and Professional, London, 116-134. 

Acid-catalyzed condensation of L-aspartic acid yields an authenticated biodegradable polymer [118] by standard biodegradation test methodology. The noncatalyzed polymerization and the ammonia/maleic acid processes give partially (ca 30 wt % residue remains in the Sturm test) biodegradable polymers due to the molecules being highly branched and more resistant to enzymatic attack. 

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