Peel adhesion and viscoelasticity of poly(ethylene-co-vinyl acetate)-based hot melt adhesives. I. The effect of tackifier compatibility

✍ Scribed by H.-H. Shih; G. R. Hamed

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 251 KB
• Volume: 63
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(19970118)63:3<323::aid-app7>3.0.co;2-p

✦ Synopsis

A series of poly(ethylene-co-vinyl acetate) (EVA)-based hot melt adhesives containing either a rosin or a hydrocarbon (C5-C9) tackifier have been prepared to investigate viscoelastic properties and peel adhesion. Fracture energies were determined by the use of a T-Peel geometry (two polypropylene films bonded with model EVA adhesives). The rosin has only one glass transition temperature, but the C5-C9 resin has two glass transition temperatures, indicating phase separation. The rosin has better compatibility with EVA than does the C5-C9 resin. The bond strength of tackified EVA to polypropylene depends not only on compatibility, but also on viscoelastic properties. A higher storage modulus results in a higher T-Peel strength. Under certain test conditions, glassy C5-C9-rich domains act as reinforcing filler, resulting in a higher storage modulus. Here, a C5-C9-tackified EVA adhesive has higher T-Peel strength than does one containing rosin.