高结晶度聚酰胺6多孔微球的制备及其表征

Fabrication and Characterization of Polyamide 6 Porous Microspheres with High Crystallinity

以聚酰胺6/间甲酚为溶液,无任何添加剂条件下,通过热致相分离(TIPS)法制备了高结晶度聚酰胺6多孔微球,微球由中心向外辐射生长的纤维组成。研究萃取剂、聚合物浓度、淬火温度和淬火时间等因素对材料形貌影响。实验结果表明:水为萃取剂得到粗纤维或颗粒,乙醇为萃取剂得到多孔微球。偏光显微镜表明该多孔微球为球晶。淬火时间0～15 min得到了直径为(0.413±0.074)μm纤维,淬火时间60～240 min得到了多孔微球。随着淬火时间延长,微球变得更加均一、规整,且微球直径由(19.14±3.62)μm增加到(30.53±3.71)μm。聚酰胺6多孔微球的孔隙率和比表面积高达95.53%和31.26 m^2/g。5℃和10℃淬火得到纤维状、芽片状或捆束状,而15℃淬火得到多孔微球。浓度从3wt%增加到7wt%时,多孔微球的直径由(15.54±2.11)μm增加到(23.21±3.32)μm。聚酰胺6多孔微球的结晶度最高达62.1%。独立形态球晶(多孔微球)为多孔材料增加了一种新形态,并可为其他结晶或非结晶性高分子独立形态的纳米纤维球晶材料的构建提供机理和技术参考。

Polyamide 6 porous microspheres with high crystallinity composed of nanofibers,which radially grow from the microsphere core,were fabricated by thermally induced phase separation from its m-cresol solutions without the assistance of other additives.The effects of extractant,concentration,quenching temperature and quenching time on the morphology of microspheres were investigated.The results show that crude fibers with diameter of(0.413±0.074)μm/particles and microspheres are obtained with quenching time of 0~15 min and 60~240 min,respectively.Moreover,porous microspheres become more uniform and regular,and the diameter increased from(19.14±3.62)μm to(30.53±3.71)μm with increasing quenching time.The porosity and specific surface areas of polyamide 6 porous microspheres reach up to 95.53%and 31.26 m 2/g,respectively.While quenching at 5℃and 10℃is favorable for the formation of fibrous or bud-like or sheaves,quenching at 15℃is inclined to form porous microspheres.When increasing solutions concentration from 3wt%to 7wt%,the microsphere diameter show a rising trend from(15.54±2.11)μm to(23.21±3.32)μm.The crystallinity of polyamide 6 porous microspheres(spherulites)reach up to 62.1%.Free spherulites provide a new form of porous materials and provide techniques and mechanism for preparation of other crystalline or non-crystalline polymer spherulites.