The effect of atmopheric pressure helium plasma treatment on the surface and mechanical properties of ultrahigh-modulus polymethylene fibers

摘要

Ultrahigh-modulus polymethylene fibers were treated wit atmospheric pressure He plasma on a capacitively coupled deviceat a frequency of 7.5 kHzand a He partial vapor pressure of 3.43 X 10~3 Pa. The fibers were treated for 0,1, and 2 min. Microscopic analysis showed that the surfaces of the fibers treated with He plasma were etched and that the 2-min He plasma-treated group had rougher surfaces than the 1-min He plasma-treated group. XPS analysis showed a 200% increase in the oxygen content and a 200% increase in the concentration of C-O bonds (from 11.4% to 31%) and the appearance of C=O bonds (from 0% to 7.6%) on the surface of plasma-treated fibers for the 2-min He plasma-treated group. In the microbond test, the 2-min He plasma-treated group had a 100% increase of interfacial shear strength over that of the control group, while the 1-min He plasma-treated group did not show a significant different from the control group. The 2-min He plasma-treated group also showed a 14% higher single-fiber tensile strength than the control group.