Rheological study on the adhesion properties of the blends of ethylene vinyl acetate/terpene phenol adhesives

✍ Scribed by Lourdes D. Turreda; Yasushi Sekiguchi; Mototsugu Takemoto; Mikio Kajiyama; Yasunori Hatano; Hiroshi Mizumachi

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 338 KB
• Volume: 70
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(19981010)70:2<409::aid-app22>3.0.co;2-x

✦ Synopsis

Measurements of the shear, tensile, peel, and creep strength of ethylene vinyl acetate (EVA)/CaCO 3 /terpene phenol adhesive system at three different ratios [100/60/0 (EVA-O), 80/48/20 (EVA-20), and 60/36/40 (EVA-40) by weight, using wood and aluminum as adherends] were conducted. Over a wide range of temperatures and rates of deformation, adhesion shear, tensile, and peel strength results, as well as the creep response over a broad range of temperature and stresses, were found to yield a single master curve by means of the reduced-variable technique. It was observed that the peak of EЉ representing Tg, shifted toward higher temperatures as the amount of terpene phenol in the blend was increased. The most obvious effect of increasing the tackifier resin was the shifting of the adhesion strength master curves to the direction of lower rates. The shift was associated with the rise in Tg as the blend ratio was increased. The influence of the tackifier resin in modifying the viscoelastic properties of the adhesive was further described in a comparison of the adhesion strength master curves with corresponding dynamic viscoelastic curves of the adhesive films. The master curves for the creep response of the adhesives showed that the stress-breaking time relationship shifts toward longer time for EVA-40 with high Tg. Thus, it was found that the strength of adhesion is due mainly to dynamic effects in the adhesive of a viscous nature in the same way to the cohesive strength of the viscoelastic materials.