Aging behavior of oxygen plasma-treated polypropylene with different crystallinities

Oxygen plasma-treated quenched and annealed polypropylene (PP) films with different crystallinities were investigated to characterize the surface rearrangement behavior during aging using contact-angle measurements and X-ray photoelectron spectroscopy. Optimum plasma conditions were examined by varying the power, time and pressure. Less crystalline quenched PP showed a larger increase in water contact angle and a larger decrease of oxygen atomic concentration during aging than the more crystalline annealed PP, since the oxygen species, such as hydroxyl groups, introduced by oxygen plasma treatment, oriented towards or diffused faster into the bulk with lower crystallinity. The degree of crosslinking on the surface was enhanced after plasma treatment and, in addition to increased crystallinity, the crosslinked structure induced by plasma treatment restricted chain mobility and lowered the aging rate of the PP surface.

[1]  D. Briggs,et al.  Practical surface analysis: By auger and x-ray photoelectron spectroscopy , 1983 .

[2]  H. Yasuda,et al.  A study of surface dynamics of polymers. II. Investigation by plasma surface implantation of fluorine–containing moieties , 1988 .

[3]  F. Poncin‐Epaillard,et al.  Reactivity of a polypropylene surface modified in a nitrogen plasma , 1994 .

[4]  Ximing Xie,et al.  Effects of plasma modification conditions on surface restructuring , 1995 .

[5]  A. Lichtenberg,et al.  Principles of Plasma Discharges and Materials Processing , 1994 .

[6]  J. Rabek,et al.  Experimental methods in polymer chemistry: Physical principles and application , 1980 .

[7]  Chi Ming Chan,et al.  Polymer surface modification and characterization , 1993 .

[8]  Jan Feijen,et al.  Selective etching of semicrystalline polymers CF4 gas plasma treatment of poly(ethylene) , 1999 .

[9]  C. M. Ryu,et al.  A closer look into the behavior of oxygen plasma-treated high-density polyethylene , 2003 .

[10]  R. W. Paynter,et al.  XPS studies of the ageing of plasma-treated polymer surfaces , 2000 .

[11]  W. Feast,et al.  Investigation of the ageing of plasma oxidized PEEK , 1991 .

[12]  N. Murthy,et al.  Depth-profiles of structure in single- and multilayered commercial polymer films using grazing-incidence X-ray diffraction , 2000 .

[13]  J. Gardella,et al.  Surface chemical studies of aging and solvent extraction effects on plasma-treated polystyrene , 1994 .

[14]  M. Wertheimer,et al.  Plasma surface modification of polymers for improved adhesion: a critical review , 1993 .

[15]  F. Poncin‐Epaillard,et al.  In situ spectroellipsometry study of the crosslinking of polypropylene by an argon plasma , 1997 .

[16]  H. Mark,et al.  Encyclopedia of polymer science and engineering , 1985 .

[17]  J. Hyun,et al.  A new approach to characterize crystallinity by observing the mobility of plasma treated polymer surfaces , 2001 .

[18]  D. Aspnes,et al.  Effect of Ar+ ion beam in the process of plasma surface modification of PET films , 2000 .

[19]  T. Gengenbach,et al.  Quantitative Analysis of Polymer Surface Restructuring , 1995 .

[20]  W. Stickle,et al.  Handbook of X-Ray Photoelectron Spectroscopy , 1992 .

[21]  Z. Osawa,et al.  Dynamics of Polymeric Solid Surfaces Treated with Oxygen Plasma: Effect of Aging Media after Plasma Treatment , 1998 .

[22]  C. Chan,et al.  Polymer surface modification by plasmas and photons , 1996 .