Effects of the tacticities of poly(vinyl alcohol) on the structure and morphology of poly(vinyl alcohol) nanowebs prepared by electrospinning
2019/11/27 21:31:17
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The effects of tacticities on the characteristics of poly(vinyl alcohol) (PVA) nanowebs prepared by an electrospinning technique were investigated. PVA webs composed of uniform nanofibers with syndiotactic dyad (s-dyad) contents of 53.5 and 57.3% were successfully obtained with electrospinning. By changing processing parameters such as the initial polymer concentration, applied voltage, and tip-to-collector distance, we found suitable conditions for forming PVA webs with uniform nanofibers. PVAs of hi-her s-dyad contents were prepared at a lower solution concentration and at a higher applied voltage because of the easy formation of syndiotactic PVA chain entanglements at a very low polymer concentration. The average diameter of the nanofibers in a PVA web with the higher s-dyad content of 57.3% (ca. 240 nm) was thinner than that of the nanofibers in a PVA web with the lower s-dyad content of 53.59% (ca. 270 nm). In addition, the crystallinity and thermal stability were greatly increased with an increase in the s-dyad content. (c) 2007 Wilev Periodicals, Inc.

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