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The estimation of degradability of different polyurethanes under natural weather depending conditions in compost pile was the subject of this study. The incubation of polymer samples took place for a period up to 24 months. The characteristic parameters of the compost: temperature, pH, moisture content, and activity of dehydrogenases were monitored and their influence on degradation of polyurethanes was discussed. The compostability of polyurethanes was investigated by changes of weight, tensile strength, morphology, and thermal properties. The degradation study revealed that the degree of degradation of polyurethanes in the natural environment, like compost, is dependent on their chemical and structural composition. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Abstract. The aim of this work was an estimation of susceptibility of biodegradable poly(-caprolactone) (PCL) to environmental degradation in different natural environments. The commercial poly(-caprolactone) film, the trade name "CAPA 680", was degraded in the compost, pond, open and harbour area of the Baltic Sea. Characteristic parameters of all natural environments were monitored during the incubation of polymer samples and their influence on degradation of PCL was discussed. Susceptibility of PCL to degradation in natural environments was evaluated based on changes of weight, crystallinity and polymer surface morphology. The rate of environmental degradation of PCL depended on the incubation place, environmental conditions and decreased in order: compost>harbour area of the Baltic Sea>open area of the Baltic Sea>pond.

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Degradacja wybranych syntetycznych poliestrów w warunkach naturalnych Streszczenie-Przedstawiono wyniki badañ degradacji wybranych syntetycznych poliestrów, mianowicie poli(L-laktydu) (PLLA), poli[(DL)-laktydu] (PLA) oraz alifatyczno-aromatycznego kopoliestru kwas tereftalowy/kwas adypinowy/1,4-butanodiol (BTA) w warunkach kompostowania przemy-s³owego, a tak¿e w kompooecie z osadem czynnym, w standaryzowanej glebie i w dynamicznej wodzie morskiej. Przebieg procesu degradacji oeledzono oceniaj¹c zmiany ciê¿aru cz¹steczkowego próbek metod¹ GPC, makroskopowe zmiany ich powierzchni oraz zmiany masy. Stwierdzono, ¿e najwiêksze zmniejszenie ciê¿aru cz¹steczkowego oraz wyraŸna dezintegracja badanych materia³ów polimerowych (zw³aszcza próbki PLA) zachodzi podczas degradacji w warunkach kompostowania przemys³owego. Jest to wiêc w³aoeciwe oerodowisko degradacyjne badanych, podatnych na kompostowanie polimerów, albowiem proces ich degradacji w pozosta³ych oerodowiskach zachodzi znacznie wolniej. Oceniono równie¿ zmiany charakterystycznych w³aoeciwooeci stosowanych oerodowisk w toku trwaj¹cego do 6 miesiêcy procesu degradacji polimerów. Ponadto na podstawie testu fitotoksycznooeci stwierdzono brak jakiegokolwiek niekorzystnego wp³ywu produktów degradacji inkubowanych w glebie próbek PLLA oraz PLA na wzrost i rozwój wysianych w niej nasion rooelin. S³owa kluczowe: polilaktyd, poliestry alifatyczno-aromatyczne, biodegradacja, kompost przemys³owy, standaryzowana gleba, dynamiczna woda morska, kompost z osadem czynnym. DEGRADATION OF SELECTED SYNTHETIC POLYESTERS IN NATURAL CONDITIONS Summary-The results of the study on degradation of selected synthetic polyesters namely poly(L-lactide) (PLLA), poly[(DL)-lactide] (PLA) and aliphatic-aromatic co-polyester terephthalic acid/ adipic acid/1,4-butanediol (BTA) in the industrial compost heap, a compost containing activated sludge, standardized soil or dynamic sea water were presented. The course of degradation process was monitored by evaluation of changes of molecular weights of the samples by GPC method (Fig. 1, 3, 4 and 7), macroscopic changes of the surface (Fig. 2) and weight loss. It has been found that most significant decrease in molecular weight and clear disintegration of the materials investigated (particularly PLA samples) took place during the degradation under the industrial composting conditions. So this is the proper degradation environment for the tested compostable polymers, for their degradation processes in the other environments go much more slowly. The changes in the characteristic properties of the environments used were also evaluated during the process of polymers' degradation up to six-month time (Table 1, 2 and 5). Additionally, on the basis of the results of phytotoxicity test, no harmful effects of the degradation products of PLA and PLLA samples, incubated in the soil, on the growth and development of the plants seeds sown in the soil has been found (Fig. 5 and 6, Table 3 and 4).

The growing interest in environmental issues and increasing demands to develop materials that do not burden the natural environment significantly are currently observed. In this connection many studies on polymer degradation in different environments are carried out. It is important to consider the influence of synergistic action of various factors in order to understand the environmental degradation of synthetic polymers. This requires understanding of interactions between polymer and living organisms. This paper reviews current authors research on environmental degradation of polyurethanes.The comparison of environmental degradability of polyurethanes in the "altic Sea water and compost under natural weather depending conditions is presented. The environmental degradation of poly ester-urethane based on poly ethylene-butyleneadipate and poly ester-urethane based on poly ε -caprolactone was evaluated.The characteristic parameters of sea water temperature, pH, salt, and oxygen contents and of compost temperature, pH, moisture content, and activity of

Polylactides were prepared by ring-opening polymerization (ROP) in bulk using as catalyst either stannous 2-ethylhexanoate at a monomer to catalyst ratio of 2000, or ferrous acetate (Fe(OAc) 2 ) at monomer to catalyst ratios of 500, 1000, 2000 and 3000. The crystallization behaviour was studied for the prepared polymers as well as the degradation behaviour both in laboratory and natural compost environments by using differential scanning calorimetry, size exclusion chromatography, Xray diffractiometry and microscopy. No differences were apparent due to the choice or amount of catalyst used, except for those which could be related to the increased racemization when the Fe(OAc) 2 was used.