液体冷却工艺对聚偏氟乙烯单丝结构及性能的影响  

Effect of liquid cooling process on structure and properties of polyvinylidene fluoride monofilament

作　　者：徐燕 马海燕 马海军[1] XU Yan;MA Haiyan;MA Haijun(Nantong NEWTEC Monofilament Technical Co.,Ltd.,Nantong 226003;College of Chemistry and Chemical Engineering,Nantong University,Nantong 226003)

机构地区：[1]南通新帝克单丝科技股份有限公司,江苏南通226003 [2]南通大学化学化工学院,江苏南通226003

出　　处：《合成纤维工业》2024年第2期19-23,共5页China Synthetic Fiber Industry

摘　　要：采用聚偏氟乙烯(PVDF)切片通过熔融纺丝制备PVDF单丝,根据PVDF切片的熔点确定纺丝温度范围,重点研究液体冷却工艺对PVDF初生丝结构与性能,以及PVDF单丝力学性能的影响。结果表明:PVDF切片的熔点为176℃,合适的纺丝温度为200~230℃;液体冷却温度为40~70℃条件下,PVDF初生丝形成的晶体结构一样,都是α晶型;液体冷却温度为50℃时PVDF结晶成核和晶体生长速率都较快,PVDF初生丝的结晶较完善,结晶度达55.7%,(100)晶面的晶粒尺寸为42 nm,有利于后道拉伸;随着液体冷却温度的升高,PVDF单丝的断裂强度呈先增后降的变化趋势,在喷丝头拉伸倍数为8、液体冷却温度为50℃时纺丝稳定性最好,PVDF单丝的断裂强度、断裂伸长率最高,分别为5.57 cN/dtex、35%。Polyvinylidene fluoride(PVDF)monofilaments were prepared from PVDF chip by melt spinning.The spinning temperature range was determined based on the melting point of PVDF chip.And the influence of liquid cooling process on the structure and properties of as-spun PVDF filaments and the mechanical properties of PVDF monofilaments was studied.The results showed that the appropriate spinning temperature was 200-230℃when the melting point of PVDF chip was 176℃;the as-spun PVDF fibers formed the same crystal structure ofαcrystal form at a liquid cooling temperature of 40-70℃;the nucleation and crystal growth rate of PVDF were relatively high and the as-spun PVDF fiber exhibited relatively perfect crystalline structure with a crystallinity of 55.7%and the grain size of 42 nm at crystal plane(100),which was beneficial to the subsequent stretching,when the liquid cooling temperature was 50℃;the breaking strength of PVDF monofilament showed a first increasing and then decreasing trend as the liquid cooling temperature increased,and the spinning stability was optimized and the PVDF monofilament had the highest breaking strength and elongation at break of 5.57 cN/dtex and 35%,respectively,when the stretching ratio of the spinneret was 8 and the liquid cooling temperature was 50℃.

关 键 词：聚偏氟乙烯纤维 单丝 液体冷却 结晶结构 力学性能 

分 类 号：TQ342[化学工程—化纤工业]