Effect of liquid cooling process on structure and properties of polyvinylidene fluoride monofilament
Polyvinylidene fluoride(PVDF)monofilaments were prepared from PVDF chip by melt spinning.The spinning tem-perature range was determined based on the melting point of PVDF chip.And the influence of liquid cooling process on the struc-ture 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 of α crystal 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 monofila-ment 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℃.
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万方数据
维普
