【摘要】 采用水为单一增塑剂,通过增塑熔融纺丝法制备出聚乙烯醇(PVA)原丝,经过干燥、热拉伸后得到大直径PVA纤维,并对拉伸倍数分别为12,14,15,16的PVA纤维进行结构与性能研究。结果表明:随着拉伸倍数的增加,PVA纤维的拉伸强度和弹性模量均先增大后降低,且纤维断裂伸长率的变化率也逐渐降低,PVA纤维的拉伸强度均超过1.0 GPa,弹性模量为37～51 GPa;随着拉伸倍数的增加,PVA纤维的结晶度和(101)晶面的晶粒尺寸逐渐增大,(200)晶面的晶粒尺寸逐渐降低;通过扫描电镜观察发现,PVA纤维表面形貌良好,表面密布纵向沟槽,拉伸倍数分别为12,14,15,16的PVA纤维,其直径分别为106.0,98.0,94.8,92.0μm;当大直径(106.0μm)PVA纤维在水泥基中的掺量达到20 kg/m~3时,纤维在水泥基中分散均匀,未出现团聚现象。更多还原

【Abstract】 Polyvinyl alcohol(PVA) precursor was prepared by plasticized melt spinning with water as a single plasticizer and was produced into PVA fibers with large diameter after drying and hot drawing. The structure and properties of PVA fiber were studied at the draw ratios of 12, 14, 15 and 16. The results showed that the tensile strength and elastic modulus of PVA fiber were both increased and then decreased and the change of the elongation at break became moderate with the increase of draw ratio, and the tensile strength of PVA fiber exceeded 1.0 GPa and the elastic modulus was 37-51 GPa; the crystallinity of PVA fiber and the grain size in crystal plane(101) gradually increased, but the grain size gradually decreased in crystal plane(200) with the increase of draw ratio; PVA fiber exhibited good surface morphology densely covered with longitudinal grooves, and the diameters of PVA fiber were 106.0,98.0,94.8 and 92.0 μm at the draw ratios of 12,14,15 and 16, respectively; and the fiber was evenly dispersed in cement base without agglomeration when the content of large-diameter(106.0 μm) PVA fiber in cement base reached 20 kg/m~3.更多还原