热台原子力显微镜研究PVDF/PBA共混物的表面结晶形态

Study of the morphology of poly(vinylidene fluoride)/poly(butylene adipate) blends using hot-stage atomic force microscopy

制备了低温结晶的聚偏氟乙烯(PVDF)/聚己二酸丁二酯(PBA)共混物薄膜.使用热台原子力显微镜跟踪研究PVDF/PBA共混物薄膜样品的原位熔融过程,从片晶尺度上考察不同的共混比例对相分离形态结构的影响规律.结果表明,当PVDF/PBA共混体系在低温下结晶时,PBA组分主要在PVDF的片晶间的区域内分布;共混比例影响两组分都结晶后的片晶排列方式;PBA组分含量较低时,两组分片晶的排列方式主要为"ABABABAB",PBA中等含量时,两组分片晶的排列方式主要为"ABBBABBB";片晶间分相结构对PBA的结晶扩散有抑制作用,PBA组分要充分结晶需要较高的过冷度或者足够长的结晶时间.

Blends of poly（vinylidene fluoride）（PVDF）/poly（butylene adipate）（PBA） were cast into films,melted,and crystallized at low temperature.In-situ melting process of PBA in PVDF/PBA blends varying in blend ratio was studied using hot-stage atomic force microscopies.The effects of the blend ratios on the phase separation were investigated at the lamellar level.It was found that the PBA component is mainly restricted in the interlamellar regions of the PVDF component when their blend is crystallized at low temperature;The arrangement of the two crystal species is affected by the blend ratios;An alternating configuration（ABABABAB） is formed when the content of PBA is low,and a block mode（ABBBABBB） is induced with increasing the PBA concentration;The interlamellar phase separation inhibits the crystallization process of PBA,as a result,high supercooling degree or sufficiently long crystallization time is appropriate for the complete crystallization of PBA.