Two series of waterborne polyurethane-urea anionomers were prepared by a polyaddition reaction with isophorone diisocyanate, poly(tetramethylene oxide) glycol (weight-average molecular weight ϭ 1000), dimethylol propionic acid (DMPA), and ethylene diamine as chain extenders. Triethylamine (TEA) or 28:1 mol/mol ammonium hydroxide (NH 4 OH)/cupric hydroxide [Cu(OH) 2 ] was used as a neutralization agent [NH(C 2 H 5 ) 3 ϩ or NH 4 ϩ / Cu 2ϩ counterion] for the pendant COOH group of DMPA. The effects of the degree of neutralization and counterion on the particle size of the dispersions, the conductivity, and the antibacterial and mechanical properties of polyurethaneurea anionomer films were investigated. The particle sizes of the two sample series dispersions decreased with an increasing degree of neutralization. Aqueous dispersions of polyurethane-urea anionomers with particle sizes of 30 -120 nm were stable for about 3 months. By infrared spectroscopy, it was found that TEA-based samples (T series) had higher fractions of hydrogen-bonded carbonyl groups in the ordered region than NH 4 OH/Cu(OH) 2 -based samples (S series). However, the fractions of hydrogen-bonded carbonyl groups in the disordered region of the S-series samples were higher than those of the T-series samples. The conductivities of the S-series film samples were higher than those of the T-series samples. However, the T-series film samples commonly had higher tensile strengths and initial moduli than the S-series samples.

ABSTRACT:To improve the interfacial adhesion between evaporated copper film and low-density polyethylene (LDPE) film, the surface of LDPE films was modified by treating with chromic acid [K 2 Cr 2 O 7 /H 2 O/H 2 SO 4 (4.4/7.1/88.5)]/oxygen plasma. Chromic-acid-etched LDPE was exposed to oxygen plasma to achieve a higher content of polar groups on the LDPE surface. We investigated the effect of the treatment time of chromic acid in the range of 1-60 min at 70°C and oxygen plasma in the range of 30 -90 sec on the extent of polar groups created on the LDPE. We also investigated the surface topography of and water contact angle on the LDPE film surface, mechanical properties of the LDPE film, and adhesion strength of the evaporated copper metal film to the LDPE film surface. IR and electron spectroscopy for chemical analysis revealed the introduction of polar groups on the modified LDPE film surface, which exhibited an improved contact angle and copper/LDPE adhesion. The number of polar groups and the surface roughness increased with increasing treatment time of chromic acid/ plasma. Water contact angle significantly decreased with increasing treatment time of chromic acid/plasma. Combination treatment of oxygen plasma with chromic acid drastically decreased the contact angle. When the treatment times of chromic acid and oxygen plasma were greater than 10 min and 30 sec, respectively, the contact angle was below 20°. With an increasing treatment time of chromic acid, the tensile strength of the LDPE film decreased, and the film color changed after about 10 min and then became blackened after 30 min. With the scratch test, the adhesion between copper and LDPE was found to increase with an increasing treatment time of chromic acid/oxygen plasma. From these results, we found that the optimum treatment times with chromic acid and oxygen plasma were near 30 min and 30 sec, respectively.

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