Effect of water and acid–base reactants on adhesive properties of various plasticized poly(vinyl butyral) sheets

Abstract

We study the changes in adhesive properties of poly(vinyl butyral) (PVB) sheets assigned for safety glass preparation. PVB sheets have been produced by various worldwide manufacturers by simple blending methods such as extrusion, thermo‐mechanical mixer processes, etc. Some samples were modified either by magnesium acetate or by oligo‐functional organic acid to either reduce the adhesion to glass or to increase it. Adhesive measurements were evaluated on the air side and the tin side of the laminated glass. The study deals with a recognition of causes of the PVB adhesion change as a function of adsorbed water content into the polymer matrix. Results describe the influence of hydroxyl group content and amount of added acid–base reactants for adhesion adjustment of every tested PVB sheet. It also describes typical adhesion fluctuation and specific adhesion bonding of PVB sheets to glass in particular conditions. The analysis evaluates the best and the worst blend combinations and their modification on the adhesion change. We focused on adhesion sensitivity to increasing water content and the amount of added adhesion modifier. This work also evaluated the critical range of water content that provides adhesion fluctuation. The evaluation of various types of PVB sheets was performed and the most stable adhesion adjustment was found. Obtained values and comparisons are very important for the PVB sheets industry and for industry dealing with lamination of laminated glasses. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Windshield recycling focused on effective separation of PVB sheet

“…Unfortunately, PVB obtained in this way contains high degree of glass dust (1-5%, w/w) and other contaminants (sludge, paper, and other plastics). 6,8,10,12 In contrast to the dry recycling process, wet (water based) process seems to be better for the delamination and glass separation from PVB sheet. Aqueous medium more effectively wash out the glass and other contaminations; moreover water also break the hydrogen bonds between the glass and the -OH groups of PVB.…”

“…Aqueous medium more effectively wash out the glass and other contaminations; moreover water also break the hydrogen bonds between the glass and the -OH groups of PVB. 6,13 It was found that water content around 2% (w/w) in PVB saturated adhesion bridges. 2,6,11 Residual adhesion is caused only by weak dispersion forces as well.…”

“…6,13 It was found that water content around 2% (w/w) in PVB saturated adhesion bridges. 2,6,11 Residual adhesion is caused only by weak dispersion forces as well. 6,11 Nevertheless recycled PVB obtained by water based method contain only smaller glass dust in content (0.5-3%, w/w).…”

“…1,4,5 However, the plasticizer should not reduce light transmittance through the sheet, PVB adhesion to glass, generate haze and yellowness, and migrate out of the polymer matrix. 6,7 In addition, plasticizer must have perfect compatibility with the polymer and should not be volatile during the processing conditions.…”

“…The PVB is the material which can connect together two sheets of float glass resulting in the laminate with excellent optical and mechanical properties. [1][2][3][4][5][6] Most significant PVB properties are elasticity, strength, toughness, high light transmission and adhesion to glass and metals. Toughness of PVB sheet depends mainly on the molecular weight of PVB.…”