| 摘要 |
<p>PURPOSE:To obtain a polytetrafluoroethylene filament having excellent tensile strength and at the same time such large tensile break strength that is not available before. CONSTITUTION:A polytetrafluoroe thylene filament has apparent specific gravity of >=2, degree of orientation of >=0.9, degree of crystallization of g 90%, tensile strength of >=5g/d and tensile elongation at breakage of >=15%. The filament also has two independent endothermic peaks at the temperature ranges of 325-350 deg.C and 370-390 deg.C attributed to crystal fusion at the heating rate of 10 deg.C/min in a thermal analysis (DSC) in which the ratio of crystal fusion energy of the higher temperature side peak to that of the lower temperature side peak is >=2.</p> |
