Polyesteramides biodegradation

Some 50 years later, in the 1990s Bayer produced their BAK polyesteramides by co-reacting either hexamethylene diamine or e-caprolactam with adipic acid and butane glycol. These materials do have sufficient regularity to be crystallisable and are of interest as biodegradable plastics and are discussed further in Chapter 31. 

In previous publications, we have tested the association of TPS with different biodegradable polyesters polycaprolactone (PCL),2 polyesteramide (PEA),6 polybutylene succinate-adipate (PBSA),7 polybutylene adipate coterephtalate... 

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. 

X. Liu, Y. Zou, G. Cao, D. Luo, The preparation and properties of biodegradable polyesteramide composites reinforced with nano-CaCOj and nano-SiO, Mater. Lett. 61 (2007) 4216-4221. 

P.J.A. in t Veld, P.J. Dijkstra, J. Feijen, Synthesis of biodegradable polyesteramides with pendant functional groups. Makromol. Chem. 

Multilayer co-extrusion is another technique used in the preparation of starch/ synthetic sheets or films [164, 263-266], in which TPS is laminated with appropriate biodegradable polymers to improve the mechanical, water-resistance and gas-barrier properties of final products. These products have shown potential for applications such as food packaging and disposable product manufacture. Three-layer co-extrusion is most often practiced, in which a co-extrusion line consists of two single-screw extruders (one for the inner starch layer and the other for the outer polymer layers) a feedblock a coat-hanger-type sheet die and a three-roll calendering system [164]. Biodegradable polyesters such as PCL [164, 264], PLA [164, 263], and polyesteramide, PBSA and poly(hydroxybutyrate-co-valerate) [164] are often used for the outer layers. These new blends and composites are extending the utilization of starch-based materials into new value-added products. 

Z. Qian, S. Li, Y. He, C. Li and X. Liu, Synthesis and thermal degradation of biodegradable polyesteramide based on e-caprolactone and 11-aminoundeca-noic acid , Polym Degrad Stabil, 2003, 81, 279-86. 

Danyadi L, Moczo J, Pukanszky B (2010) Effect of various surface modifications of wood flour on the properties of PPAvood composites. Compos A 41 199-206 Dash BN, Sarkar M, Rana AK, Mishra M, Mohanty AK, Tripathy SS (2002) A study on biodegradable composite prepared fi om jute felt and polyesteramide (BAK). J Reinf Plast Compos 21 1493-1503... 

B.N. Dash, M. Sarkar, A.K. Rana, M. Mishra, A.K. Mohanty, S.S. Tripathy, A study on biodegradable composite prepared from jute felt and polyesteramide (BAK). J. Reinf. Plast Compos. 21,1493-503 (2002). 

Fan, Y., M. Kobayashi, and H. Kise. 2000. Synthesis and biodegradability of new polyesteramides containing peptide linkages. Polymer Journal 32(10) 817-822. 

Andini, S., Ferrara, L., Maglio, G. and Palumbo, R. (1988) Synthesis of block polyesteramides containing biodegradable poly(L,L-lactide) segments. Makromol. Chem. Rapid Commun., 9, 119-124. 

Blends or composites materials have been produced by the processing of starch with biodegradable polymers such as poly(s-caprolactone), pofy(lactic acid), pofy(virtyl alcohol), pofy(ltydroxybutyrate-co-valerate), and polyesteramide. The most common are Mater-Bi from Novamorrt arrd Ecostar from Natiortal Starch. 

BAK 1095, commercial polyesteramide based on caprolactam, butanediol and adipic acid was fonnd to be completely biodegradable according to German compostability standard DIN 54900 [113], Biodegradability of laboratory synthesized poly(esteramide) was studied in the controlled composting test according to EN 14046 standard [114], It was found that poly(esteramide) meets the biodegradation criteria of the standard. 

Carbon dioxide formation was measured by Keller et al. [44] who studied the kinetics of aerobic biodegradation of fiber composites comprised of degummed hemp and a polyesteramide in a column that contained 300 g of soil mixed with a fiber composite. A constant stream of oxygen was passed through the column and the effluent gas was passed through a sodium hydroxide solution to trap the carbon dioxide resulting from mineralization of the fiber... 

Synthetic biodegradable polymers are generally made by polycondensation methods from petroleum-based feedstocks. However, different from other petrochemical-based resins that may take centuries to degrade, these synthetic polyesters decompose rapidly into carbon dioxide, water, and humus under appropriate conditions where they are exposed to the combined attack of water and microorganisms [109, 116, 117). Petroleum-based biodegradable polymers that have been used in bionanocomposites are PCL, polyesteramides (PEAs), PBS, aliphatic polyesters (APES), and poly(vinyl alcohol) (PVA) [116]. 

Biodegradable polymers can also be produced from petroleum sources and are comprised of aliphatic polyesters and copolyesters (e.g., PBS, and poly(butylene succinate adipate)—PBSA), aromatic copolyesters (e.g., poly(butylene adipate terephthalate)—PBAT), poly(e-caprolactone) PCL, polyesteramides (PEA), and poly(vinyl alcohol) (PVA). Further details concerning the synthesis of these polymers can be found in the book by Rudnik (2008). In this section we summarize some of the key properties of these materials... 

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