Several waterborne polyurethane adhesives containing different chain extenders were prepared by using the acetone process. Concretely, the polyurethane dispersions were synthesized by the prepolymer method based on three chain extenders: two diols and one diamine: 1,4-butanediol, 1,6-hexanediol and hydrazine.
The adhesive solutions were characterized by flow rheology, pH measurements, particle size and solids content. The solid adhesive films were characterized by plate-plate rheology, dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC). The adhesion properties were measured from T-peel test of leather/polyurethane adhesive/SBR rubber joints.
As a result, the chosen chain extender influences significantly the polyurethane synthesized properties, specially determines the crystallinity of the polymer, as well as thermal and adhesive properties. Particularly, the molecular weight of the chain extender determines the structure of the synthesized polyurethanes.
European Directive 1999/13/EC (March 11, 1999) on the limitation of emissions of volatile organic compounds due to the use of organic solvents in certain activities and installations.
2.
European Directive 2004/42/EC (April 21, 2004) on the limitation of emissions of volatile organic compounds (VOCs) due to the use of organic solvents in certain paints and varnishes and products renewal finished vehicles, amending European Directive 1999/13/EC.
Pérez-LimiñanaMA., Arán-AisF., Torró-PalauA.M., Orgilés-BarcelóA.C., Martín-MartínezJ.M.Structure-properties relationships in waterborne polyurethane adhesives. Proceedings of the Fifth Congress of Latex and Synthetic Polymer Dispersions, Madrid (Spain) January 23 (2008).
9.
Pérez-LimiñanaM.A., Arán-AisF., Torró-PalauA.M., Orgilés-BarcelóA.C., Martín-MartínezJ.M.Influence of the hard-to-soft segment ratio on the adhesion of water-borne polyurethane adhesives, J. Adh. Sci. & Technol., 21 (8), 755–773 (2007).
10.
Pérez-LimiñanaM.A., Arán-AisF., Torró-PalauA.M., Orgilés-BarcelóA.C., Martín-MartínezJ.M.Effect of method of synthesis and the hard segment content on the properties of waterborne polyurethane adhesives, Pintture e Vernicci. European Coatings, 2, 55–64 (2007).
11.
Pérez-LimiñanaM.A., Arán-AisF., Torró-PalauA.M., Orgilés-BarcelóA.C., Martín-MartínezJ.M.Structure and properties of waterborne polyurethane adhesives obtained by different methods, J. Adh. Sci. & Technol., 20, 519–536 (2006).
12.
Pérez-LimiñanaM.A., Arán-AisF., Torró-PalauA.M., Orgilés-BarcelóA.C., Martín-MartínezJ.M.Characterization of waterborne polyurethane adhesives containing different amounts of ionic groups, Int. J. Adhesion & Adhesives, 25, 507–517 (2005).
13.
Pérez-LimiñanaM.A., Arán-AisF., Torró-PalauA.M., Orgilés-BarcelóA.C., Martín-MartínezJ.M.Influence of the nature of diisocyanate on the properties of waterborne polyurethane adhesives, Proceedings of the Ninth International Conference on the Science and Technology of Adhesion and Adhesives, Oxford (UK) September 7 (2005).
14.
RahmanM.M., KimH.D.Characterization of waterborne polyurethane adhesives containing different soft segments, J. Adh. Sci. Technol., 21, 1, 91–96 (2007).
15.
RahmanM.M., KimH.D., LeeW.L.Properties of waterborne polyurethane adhesives: effect of chain extender and polyol content, J. Adh. Sci. Technol., 23, 177–193 (2009).
16.
RahmanM.M., KimH.D., LeeW.L.Properties of isocyanate-Reactive waterborne polyurethane adhesives: effect of cure reaction with various polyol and chain extender content, J. Applied Polym. Sci., 114, 3767–3773 (2009).
17.
SemsarzadehM. A., SadeghiM., BarikaniM.Effect of Chain Extender Length on Gas Permeation Properties of Polyurethane Membranes, Iranian Polym. J., 17 (6), 431–440 (2008).
18.
SperlingL.H.Introduction to Physical Polymer Science, 4th ed, John Wiley, New York, Ch 8, (2006).
19.
CountinhoF.M.B., DelpechM.C., AlvesT.L., FerreiraA.A.Degradation profiles of cast films of polyurethane and poly(urethane-urea) aqueous dispersions based on hydroxyterminated polybutadiene and different diisocyanates, Polym. Degradation and Stability, 81, 19–27 (2003).
20.
CountinhoF.M.B., DelpechM.C.Waterborne anionic polyurethanes and poly(urethane-urea)s: influence of the chain extender on mechanical and adhesive properties, Polym. Testing, 19, 8: 939–952 (2000).
CakićS.M., RistićI.S., DjordjevićD.M., StamenkovićJ.V., StojiljkovićD.T.Effect of the chain extender and selective catalyst on thermooxidative stability of aqueous polyurethane dispersions, Prog. in Org. Coat., 67 (3): 274–280 (2010).
