中国塑料 ›› 2011, Vol. 25 ›› Issue (08): 69-74 .DOI: 10.19491/j.issn.1001-9278.2011.08.018

• 加工与应用 • 上一篇    下一篇

塑化聚乙烯醇的流变性能及发泡行为研究

吴文倩 贾青青 高伦巴根 项爱民   

  1. 北京工商大学 北京工商大学
  • 收稿日期:2011-07-22 修回日期:1900-01-01 出版日期:2011-08-26 发布日期:2011-08-26

Rheological and Foaming Behaviors of Plasticized Poly(vinyl alcohol)

  

  • Received:2011-07-22 Revised:1900-01-01 Online:2011-08-26 Published:2011-08-26

摘要: 采用毛细管流变仪对PVA流变性能进行了表征,用差示扫描量热仪(DSC)研究了降温速率对PVA结晶性能的影响,通过PVA添加化学发泡剂熔融挤出的方法制备PVA发泡材料,并用扫描电镜和密度测试仪分别对发泡材料的泡孔形态和密度进行了表征。结果表明,PVA对剪切作用非常敏感,在低剪切速率下熔体粘度较大,泡孔分布均匀,材料密度较小,在高剪切作用下熔体强度低,气体容易逃逸,导致发泡材料泡孔破裂或合并;低降温速率下熔体粘度小,泡孔易合并、塌陷,合适的降温速度下,PVA熔体粘度适中,发泡材料气泡尺寸小、分布均匀,较快的降温速度下,由于气体压力过大而造成气泡合并,联通,材料密度大。

关键词: 聚乙烯醇, 流变性能, 结晶性能, 泡孔形态, 表观密度

Abstract: The rheological properties of plasticized polyvinyl alcohol (PVA) were investigated with capillary rheometer. The effect of cooling rate on crystallization propertities of PVA was studied with differential scanning calorimetry analyzer (DSC). The PVA foams were fabricated by filling chemical foaming agent through melt extrusion, and the cell morphology and the density of the foams were investigated with scanning electron microscope (SEM) and density tester. PVA was sensitive to the shearing effect. At low shear rate, the melt viscosity of PVA was high, leading to the homogeneous distribution of the cells and a low density; at high shear rate, the melt viscosity of PVA was low and the gas was easy to escape, leading to the break or combination of the cells. At low cooling rate, the melt viscosity was low, leading to the combination or collapse of the cells; at appropriate cooling rate, the distribution of cell diameter was homogeneous; with further increase of cooling rate, the cell combined due to the excessive gas pressure, resulting in the high density of the foams.

Key words: poly(vinyl alcohol), rheological behavior, crystallization, cell morphology, apparent density