The Use of Compatible Blend of Styrene-Vinylacetate Copolymer/Natural Rubber Latex in Pressure-Sensitive Adhesive Applications by Using Irradiation and Chemical Initiation

Thermoplastic elastomers from blends of styrene-vinylacetate copolymer latex (S-VAc) and natural rubber latex (NRL) as a hydrophilic/hydrophobic blend have been prepared by the solution-casting technique. Compatibility between S-VAc and NRL was confirmed at all ratios of the blend mixing through the measurements of water absorption, thermogravimetric analysis, and scanning electron microscope. The prepared blend was studied for pressure-sensitive adhesive (PSA) application. Nonylphenol ethoxylate (NPE) was used as a chemical tackifier to initiate a sticky property for S-VAc. Also, electron beam irradiation was applied as a physical tackifying agent to promote stickiness for NRL at 12.5 Mrad or at 2.5 Mrad by addition of NPE tackifier. Peel strength, tensile strength, elongation at break, surface hardness, and aging time were investigated. Two types of double-sided PSA were prepared: the first to be applied at room temperature; the second to be applied thermally at 80 degrees C. The obtained PSA adhesive was suggested to be used for adhering the synthetic veneers to the particle wood panels. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 114: 157-165, 2009