NUCLEATION INDUCED BY PHASE SEPARATION IN THE INTERFACE OF POLYOEFIN BLEND
The two-step quenching experiments, which were performed to investigate the interplay between liquid-liquid phase separation (LLPS) and crystallization in polyolefin blend system (Zhang et al., Macromol Rapid Commun 26 1285 (2005) 1 and the following papers.), showed that almost all the nuclei appear in the interfacial regions of phase separation. The nucleation rates in the second step quenching decay with the time of phase separation in a simple power law. These novel phenomena are attributed to that the interdiffusion in the spinodal decomposition process makes the polymer chains oriented in the interfacial regions. The orientation of polymer chains decreases the nucleation barriers of crystallization. a reasonable assumption is that the nucleation rate is proportional to the interfacial volume. In the early stage of phase separation, the interface thinning process is faster than the phases coarsening process, and hence the interfacial area is approximately kept the same, and the nucleation rate is then proportional to the interfacial thickness. Based on this assumption, the time dependent interface thinning down in the spinodal decomposition process must follow the same law of nucleation rates versus the time of phase separation.
Xinghua Zhang Xingkun Man Charles C.Han Dadong Yan
Beijing National Laboratory for Molecular Sciences (BNLMS),State Key Laboratory of Polymer Physics and Chemistry,Joint Laboratory of Polymer Science and Materials,Institute of Chemistry,Chinese Academy of Sciences,Beijing 100190,China
国际会议
International Symposium on Polymer Physics(2008年国际高分子物理学术会议PP2008)
厦门
英文
465-466
2008-06-08（万方平台首次上网日期，不代表论文的发表时间）