caa a22 4500 445384778 CHVBK 20180317143029.0 cr unu---uuuuu 170323e20110901xx s 000 0 eng 10.1007/s10924-011-0301-9 doi (NATIONALLICENCE)springer-10.1007/s10924-011-0301-9 Crystal and Thermal Properties of PLLA/PDLA Blends Synthesized by Direct Melt Polycondensation [Elektronische Daten] [Dakai Chen, Jing Li, Jie Ren] We herein report the effects of the component ratio and method of blending on the synthesis of stereocomplex poly(lactic acid) (SC-PLA) based on poly(l-lactic acid) (PLLA) and poly(d-lactic acid) (PDLA) prepolymers. PLLA and PDLA were prepared by direct melt polycondensation of lactic acid (DMP). Combined with the dual catalyst system, PLA prepolymers with Mw more than 20,000 were prepared by DMP. PLLA was mixed by powder blending or melt blended with PDLA. It is revealed that melt-point and spherulite growth rate of SC-PLA is strongly dependent on the perfection of SC structure. The melt point of PLA can be increased by nearly 50°C because of the particular strong intermolecular interaction between PLLA and PDLA chains. Solid-state polycondensation (SSP) is an efficient method to increase the molecular weight of SC-PLA, but it can have a negative effect on the regularity of linear chains of SC-PLA. Thermogravimetry analyzer (TGA) results show that SC structure cannot cause the delay reaction on the thermal degradation of PLA. Springer Science+Business Media, LLC, 2011 SC-PLA nationallicence Spherulite growth rate nationallicence Thermal degradation nationallicence Chen Dakai Institute of Nano- and Bio-Polymeric Materials, School of Material Science and Engineering, Tongji University, 200092, Shanghai, China aut Li Jing Institute of Nano- and Bio-Polymeric Materials, School of Material Science and Engineering, Tongji University, 200092, Shanghai, China aut Ren Jie Institute of Nano- and Bio-Polymeric Materials, School of Material Science and Engineering, Tongji University, 200092, Shanghai, China aut Journal of Polymers and the Environment Springer US; http://www.springer-ny.com 19/3(2011-09-01), 574-581 1566-2543 19:3<574 2011 19 10924 https://doi.org/10.1007/s10924-011-0301-9 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10924-011-0301-9 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Chen Dakai Institute of Nano- and Bio-Polymeric Materials, School of Material Science and Engineering, Tongji University, 200092, Shanghai, China aut NATIONALLICENCE 700 1- Li Jing Institute of Nano- and Bio-Polymeric Materials, School of Material Science and Engineering, Tongji University, 200092, Shanghai, China aut NATIONALLICENCE 700 1- Ren Jie Institute of Nano- and Bio-Polymeric Materials, School of Material Science and Engineering, Tongji University, 200092, Shanghai, China aut NATIONALLICENCE 773 0- Journal of Polymers and the Environment Springer US; http://www.springer-ny.com 19/3(2011-09-01), 574-581 1566-2543 19:3<574 2011 19 10924 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer