Dr. Yaqiong Zhang published a paper in J Phys Chem C, No. 116 paper of our group (J Phys Chem C, 2013, 117, 5882-5893)
Dr. Yaqiong Zhang''''s paper appears in J Phys Chem C, No. 116 paper of our group (J Phys Chem C, 2013, 117, 5882-5893)
Congrats!
Significantly Accelerated Spherulitic Growth Rates for
Semicrystalline Polymers through the Layer-by-Layer Film Method
Yaqiong Zhang,? Hongjun Xu,? Jingjing Yang,? Shouyu Chen,? Yunsheng Ding,? and Zhigang Wang*,?
?CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui Province 230026, P. R. China
?Institute of Polymer Materials & Chemical Engineering, School of Chemical Engineering, Hefei University of Technology, Hefei,
Anhui Province 230009, P. R. China
The influence of a molten liquid polymer layer on the crystallization of the beneath semicrystalline polymer has been seldom considered. In the study, the nucleation and growth of spherulites for the beneath polylactide (PLA) layer in poly(ethylene oxide)/polylactide (PEO/PLA) double-layer films during isothermal crystallization at various temperatures above the melting point of PEO have been investigated by using polarized optical microscopy, with the particular results compared with that for neat PLA and PLA/PEO blend films. It is interesting to find that the top covering molten PEO layer can greatly accelerate the spherulitic growth rate (G) of the beneath PLA layer. Another significant result is that the temperature for the measurable nucleation and spherulitic growth of PLA in the double-layer films can be eventually pushed down close to the glass transition temperature of neat PLA. The changes of glass transition temperature, Tg, for PEO/PLA multilayer films have been measured by using modulated differential scanning calorimetry and dynamic mechanical analysis, which reveal slight decreases of Tg for PLA layer due to the influence of PEO layer. The layer structures of fractured surface of the double-layer films are analyzed on the basis of the observation from scanning electron microscopy, and the existence of interdiffusion areas with irregular boundary between PEO and PLA layers is the key clue to understanding the significant acceleration of G for PLA. The layer-by-layer film method infers promising applications, which might be considered to well replace the blending method.