TIME EVOLUTION OF PHASE STRUCTURE AND CORRESPONDING MECHANICAL PROPERTIES OF IPP/PEOC BLENDS IN THE LATE-STAGE PHASE SEPARATION
A typical toughened polymeric alloy system, isotactic polypropylene/poly(ethylene-co-octane) (iPP/PEOc) blend, was selected in this study to investigate the influence of phase separation on the final mechanical properties of the polyolefin blend. The time dependence of the morphology evolution of this iPP/PEOc blend with different compositions were annealed at 200℃ and investigated with scanning electron microscopy (SEM) and phase contrast optical microscope (PCOM). It was found that, under the phase separation temperature, the domain size of iPP80/PEOc20 (PEOc-20) increases only slightly, while the structure evolution of iPP60/PEOc40 (PEOc-40) is quite prominently (Fig. 1). The tensile tests revealed that the mechanical properties of PEOc-20, including break strength and elongation at break decrease only a very small amount, while those of PEOc-40 are depressed obviously with phase separation time (Fig. 1). The decrease of interphase and a sharper boundary resulting from domain coarsening during the late stage phase separation are responsible for the poor tensile properties (Fig. 2). It is believed that the composition, the annealing time and the processing temperatures all contribute to the morphology evolution and the consequent mechanical properties of iPP/PEOc blends.
Xia Dong Yongyan Pang Ying Zhao Charles C.Han Dujin Wang
Beijing National Laboratory for Molecular Sciences,CAS Key Laboratory of Engineering Plastics / State Key Laboratory of Polymer Physics and Chemistry,Joint Laboratory of Polymer Science and Materials,Institute of Chemistry,Chinese Academy of Sciences,Beij
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
413-414
2008-06-08（万方平台首次上网日期，不代表论文的发表时间）