Effect of composition and processing on the linear viscoelasticity of synthetic binders

Abstract The influence that composition and processing variables exert on the linear viscoelastic properties of model synthetic binders has been studied in a wide range of temperature and frequency. Model synthetic binders were prepared by blending a non-modified colophony resin (40–65%), a process aromatic oil and a styrene–butadiene–styrene (SBS) triblock copolymer (5–15%). At high SBS content (11% and 15%) and gentle processing conditions (i.e. 150 °C and 60 rpm), a plateau region in G ′ is found in the mechanical spectrum. The microstructure of this binder is characterized by a continuous SBS-rich phase. On the contrary, a shoulder in G ′ is found at low polymer content. The resulting microstructure consists of a continuous resin-rich phase and a dispersed polymer-rich phase. Under severe processing conditions (180 °C and 1200 rpm) and low polymer concentration, the polymer influence is dampened and the glassy region appears at higher temperatures or lower frequencies. At high polymer concentration, a phase inversion can be induced by processing (i.e. 180 °C and 1200 rpm.). Both resin oxidation and SBS degradation may explain such microstructural changes.

[1]  D. Lesueur.  Letter to the Editor: On the thermorheological complexity and relaxation modes of asphalt cements , 1999 .

[2]  F. Martínez-Boza,et al.  Steady-state flow behaviour of synthetic binders , 2001 .

[3]  M. Bousmina,et al.  Polymer blends for enhanced asphalt binders , 1996 .

[4]  D J Kulash,et al.  The Strategic Highway Research Program , 1991 .

[5]  U. Dutta.  Compatibility and rheological study of ASR asphalt binder , 1998 .

[6]  Jiri Stastna,et al.  Thermomechanical Properties of Several Polymer Modified Asphalts , 2000 .

[7]  Ulf Isacsson,et al.  Chemical and rheological evaluation of ageing properties of SBS polymer modified bitumens , 1998 .

[8]  L. H. Lewandowski,et al.  Polymer Modification of Paving Asphalt Binders , 1994 .

[9]  F. Martínez-Boza,et al.  Rheological characterisation of synthetic binders and unmodified bitumens , 1999 .

[10]  R. Spontak,et al.  Thermoplastic elastomer gels. I. Effects of composition and processing on morphology and gel behavior , 1998 .

[11]  F. Martínez-Boza,et al.  Effect of processing variables on the linear viscoelastic properties of SBS‐oil blends , 2001 .

[12]  Richard Gelles,et al.  Improved performance of paving asphalts by polymer modification , 1991 .

[13]  Ali Akbar Yousefi,et al.  Effect of used-tire-derived pyrolytic oil residue on the properties of polymer-modified asphalts , 2000 .

[14]  E. Windhab.  Fluid Immobilization – A Structure-Related Key Mechanism for the Viscous Flow Behavior of Concentrated Suspension Systems , 2000 .

[15]  M. Bousmina.  Rheology of polymer blends: linear model for viscoelastic emulsions , 1999 .

[16]  J. Stastna,et al.  Fractional complex modulus manifested in asphalts , 1994 .

[17]  Didier Lesueur,et al.  Polymer modified asphalts as viscoelastic emulsions , 1998 .

[18]  Linear response of regular asphalts to external harmonic fields , 1999 .

[19]  Ulf Isacsson,et al.  Artificial aging of polymer modified bitumens , 2000 .

[20]  Mary Stroup-Gardiner,et al.  Asphalt modified by SBS triblock copolymer: Structures and properties , 1996 .

[21]  Ulf Isacsson,et al.  Laboratory study on the low temperature physical hardening of conventional and polymer modified bitumens , 2000 .

[22]  J. Stastna,et al.  Response to “Letter to the Editor: ‘On the thermorheological complexity and relaxation modes of asphalt cements’ ” [J. Rheol. 43, 1701 (1999)] , 1999 .

[23]  L. Palade,et al.  Linear viscoelastic behavior of asphalt and asphalt based mastic , 2000 .

[24]  Ulf Isacsson,et al.  Low-temperature cracking of polymer-modified asphalt , 1998 .

[25]  J. Planche,et al.  A structure‐related model to describe asphalt linear viscoelasticity , 1996 .

[26]  J. Youtcheff,et al.  Mit Rheologie zu besseren Strassen / Better Roads Through Rheology , 1996 .

[27]  C. Macosko,et al.  Microstructure of triblock copolymers in asphalt oligomers , 1997 .

[28]  F. Martínez-Boza,et al.  Influence of Temperature and Composition on the Linear Viscoelastic Properties of Synthetic Binders , 2000 .

[29]  F. Martínez-Boza,et al.  Rheology and microstructure of asphalt binders , 2001 .