Elastic steric stabilization of polyethylene-asphalt emulsions by using low molecular weight polybutadiene and devulcanized rubber tire
Emulsions containing 3% polyethylene were stabilized against coalescence in an asphalt medium by low molecular weight virgin polybutadiene and recycled styrene-butadiene stabilizers. The recycled styrene-butadiene steric stabilizer precursor was obtained as a thermo-mechanical devulcanized ground rubber tire in asphalt. The low molecular weight butadiene and styrenebutadiene rubbers were in situ reacted with sulfur in order to increase the compatibility of the stabilizer with the asphalt phase.
Because of the high molar volume of the asphalt phase and the similarity in contact energy between stabilizer and matrix phase, it is assumed that the stabilization is caused by entropic effects only. The fundamental aspects of elastic stabilization of polyethylene-asphalt emulsions are discussed. The total interaction free energy profile between the polyethylene particles shows that the efficiency of the steric stabilizer formation reaction can be improved significantly.
The use of devulcanized rubber tire as a replacement for the virgin polybutadiene precursor in the in situ stabilization process can significantly reduce the cost of the technology.
Key wordsPolyethylene asphalt elastic steric stabilization styrenebutadiene ground rubber tire devulcanize
Unable to display preview. Download preview PDF.
- 1.Hesp SAM, Woodhams RT (1991) Colloid Polym, 269:825–834Google Scholar
- 2.Liang Z, Hesp SAM (1993) Colloids Surfaces (submitted for publication)Google Scholar
- 3.Evans R, Smitham JB, Napper DH (1977) Colloid Polym Sci 255:161–167Google Scholar
- 4.Hamaker HC (1937) Physica 4:399Google Scholar
- 5.Overbeek JThG (1952) In: Kruyt HR (ed) Colloid science. Elsevier Publishing Company, Amsterdam, Vol I, p 270Google Scholar
- 6.Napper DH (1983) Polymeric stabilization of colloidal dispersions. Academic Press, Sydney, AustraliaGoogle Scholar
- 7.Russel WB, Saville DA, Schowalter WR (1989) In: Colloidal dispersions. Cambridge University Press, Cambridge, England, p 315Google Scholar
- 8.Hough DB, White LR (1980) Adv Colloid Interface Sci 14:6Google Scholar
- 9.Parsegian VA and Ninham BW (1971) J Colloid Interface Sci 37(2):112Google Scholar
- 10.Hough DB, White LR (1980) Adv Colloid Interface Sci 14:29Google Scholar
- 11.Tagawa M, Gotoh K, Ikuta M (1990) Colloid Polymer Sci 268:589Google Scholar
- 12.Hesp SAM (1991) Ph.D. Thesis, University of Toronto, Toronto, Canada, pp 73–75Google Scholar
- 13.CRC Handbook of Chemistry and Physics, 61 st ed, CRC Press, Boca Raton, 1980, p E58Google Scholar
- 14.Barth EJ (1962) Asphalt Science and Technology. Gordon and Breach, N.Y., p 308Google Scholar
- 15.Gingell D, Parsegian VA (1973) J Colloid Interface Sci 44(3):456–463Google Scholar
- 16.Morawetz H (1965) Macromolecules in solution. John Wiley, N.Y., p 122Google Scholar
- 17.Kurata M, Tsunashima Y (1989) In: Bandrup J, Immergut EH (eds), Polymer handbook. John Wiley, New York, 3rd ed, p VII-33Google Scholar
- 18.Fischer EW (1950) Kolloid Z 160:1086Google Scholar
- 19.Dolan AK, Edwards SF (1974) Proc Roy Soc London A 337:509Google Scholar
- 20.The Asphalt Handbook, The Asphalt Institute, Manual Series No 4, Maryland, 1989Google Scholar
- 21.Ecoflex-Paving the way to a better world. Product literature, Bitumar Inc., Montreal, Quebec, 1993Google Scholar
- 22.Smitham JB, Napper DH (1976) J Colloid Interface Sci 54(3):468Google Scholar