title: Biodegradation of lactic acid based polymers under controlled composting conditions and evaluation of the ecotoxicological impact.
abstract: The biodegradability of lactic acid based polymers was studied under controlled composting conditions (CEN prEN 14046), and the quality of the compost was evaluated. Poly(lactic acids), poly(ester-urethanes), and poly(ester-amide) were synthesized and the effects of different structure units were investigated. The ecotoxicological impact of compost samples was evaluated by biotests, i.e., by the Flash test, measuring the inhibition of light production of Vibrio fischeri, and by plant growth tests with cress, radish, and barley. All the polymers biodegraded to over 90% of the positive control in 6 months, which is the limit set by the CEN standard. Toxicity was detected in poly(ester-urethane) samples where chain linking of lactic acid oligomers had been carried out with 1,6-hexamethylene diisocyanate (HMDI). Both the Flash test and the plant growth tests indicated equal response to initial HMDI concentration in the polymer. All other polymers, including poly(ester-urethane) chain linked with 1,4-butane diisocyanate, showed no toxicological effect.
authors: Department of Chemical Technology, Polymer Technology, Helsinki University of Technology, P.O. Box 6100, FIN-02150 HUT, Finland.
authors: Jukka
authors: J
authors: Tuominen
authors: Janne
authors: J
authors: Kylmä
authors: Anu
authors: A
authors: Kapanen
authors: Olli
authors: O
authors: Venelampi
authors: Merja
authors: M
authors: Itävaara
authors: Jukka
authors: J
authors: Seppälä
mesh_terms: D001673:Biodegradation, Environmental; D003432:Cross-Linking Reagents / Q000633:toxicity; D003485:Cyanates / Q000633:toxicity; D015386:Hazardous Substances / Q000378:metabolism / Q000633:toxicity; D017953:Isocyanates; D019344:Lactic Acid / Q000378:metabolism / Q000633:toxicity; D009757:Nylons / Q000378:metabolism / Q000633:toxicity; D010945:Plants, Edible / Q000187:drug effects / Q000254:growth & development; D011091:Polyesters; D011108:Polymers / Q000737:chemistry / Q000378:metabolism* / Q000633:toxicity*; D011140:Polyurethanes / Q000378:metabolism / Q000633:toxicity; D018675:Toxicity Tests; D014733:Vibrio / Q000187:drug effects
chemical_list: D003432:Cross-Linking Reagents; D003485:Cyanates; D015386:Hazardous Substances; D017953:Isocyanates; D009757:Nylons; D011091:Polyesters; D011108:Polymers; D011140:Polyurethanes; C015262:1,6-hexamethylene diisocyanate; D019344:Lactic Acid; C033616:poly(lactide)