caa a22 4500 467886350 CHVBK 20180406152735.0 cr unu---uuuuu 170328e20060701xx s 000 0 eng 10.1007/s10924-006-0023-6 doi (NATIONALLICENCE)springer-10.1007/s10924-006-0023-6 Enzymatic Degradation of Poly( l -Lactic Acid): Effects of UV Irradiation [Elektronische Daten] [Hideto Tsuji, Yoshihisa Echizen, Yoshiro Nishimura] Amorphous and crystallized poly(l-lactic acid) (PLLA-A and PLLA-C, respectively) films were prepared, and the proteinase K-catalyzed enzymatic degradation of UV-irradiated and non-irradiated PLLA-A and PLLA-C films was investigated for periods up to 10h (PLLA-A) and 60h (PLLA-C). The molecular weights of both the PLLA-A and PLLA-C films can be manipulated by altering the UV irradiation time. The enzymatic weight loss values of the UV-irradiated PLLA films were higher than or similar to those of the non-irradiated PLLA film, when compared with the specimens of same crystallinities. UV irradiation is expected to cause the PLLA films to undergo chain cleavage (a decrease in molecular weight) and the formation of C=C double bonds. It seems that the acceleration effects from decreased molecular weight on enzymatic degradation were higher than or balanced with the disturbance effects caused by the formation of C=C double bonds. After enzymatic degradation, a fibrous structure appeared on the spherulites of the UV-irradiated PLLA-C film. This structure may have arisen from chains containing or neighboring on the C=C double bonds, which were enzymatically undegraded and assembled on the film surface during enzymatic degradation. The results of this study strongly suggest that UV irradiation will significantly affect the biodegradation behavior of PLLA materials in the environment. Springer Science+Business Media, Inc., 2006 Poly( l -lactic acid) nationallicence Poly( l -lactide) nationallicence Enzymatic degradation nationallicence UV irradiation nationallicence Biodegradable polyesters nationallicence Tsuji Hideto Faculty of Engineering, Department of Ecological Engineering, Toyohashi University of Technology, 441-8580, Tempaku-cho, Toyohashi, Aichi, Japan aut Echizen Yoshihisa Faculty of Engineering, Department of Ecological Engineering, Toyohashi University of Technology, 441-8580, Tempaku-cho, Toyohashi, Aichi, Japan aut Nishimura Yoshiro Mikawa Textile Research Center, Aichi Industrial Technology Institute (AITEC), Aichi Prefectural Government, 443-0013, Otsuka-cho, Gamagori, Aichi, Japan aut Journal of Polymers and the Environment Kluwer Academic Publishers-Plenum Publishers; http://www.springer-ny.com 14/3(2006-07-01), 239-248 1566-2543 14:3<239 2006 14 10924 https://doi.org/10.1007/s10924-006-0023-6 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10924-006-0023-6 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Tsuji Hideto Faculty of Engineering, Department of Ecological Engineering, Toyohashi University of Technology, 441-8580, Tempaku-cho, Toyohashi, Aichi, Japan aut NATIONALLICENCE 700 1- Echizen Yoshihisa Faculty of Engineering, Department of Ecological Engineering, Toyohashi University of Technology, 441-8580, Tempaku-cho, Toyohashi, Aichi, Japan aut NATIONALLICENCE 700 1- Nishimura Yoshiro Mikawa Textile Research Center, Aichi Industrial Technology Institute (AITEC), Aichi Prefectural Government, 443-0013, Otsuka-cho, Gamagori, Aichi, Japan aut NATIONALLICENCE 773 0- Journal of Polymers and the Environment Kluwer Academic Publishers-Plenum Publishers; http://www.springer-ny.com 14/3(2006-07-01), 239-248 1566-2543 14:3<239 2006 14 10924 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer