In-situ stabilized compositions
AssigneeThe University of Toronto Innovations Foundation
InventorsZhi-Zhong Liang, Raymond T. Woodhams
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Abstract
Insoluble particulate materials, which may be in solid or liquid form, are dispersed in a continuous non-aqueous phase and the dispersion rendered stable and resistant to phase separation by an in-situ stabilization procedure involving the formation of chemical bonds among the stabilizer components and to dispersed phases to form a network surrounding the particles which is compatible with the continuous phase. The invention has particular application for the formation of stabilized polyolefin-modified bitumen compositions for paving and other applications.
Claims19
A stable composition, comprising:
- a continuous bitumen phase,
- a dispersed particulate phase of a polyolefin insoluble in said liquid phase, and
- a steric stabilizer comprising:
- (i) a first individual component comprising a functionalized olefin polymer anchored to said particulate phase,
- (ii) a second individual component different from said first component which is a functionalized diene bonded to said first component by interaction of the functional groups and soluble in said liquid phase, and
- (iii) an unfunctionalized polydiene which is partially cross-linked with said functionalized diene and itself and which is soluble in or compatible with the bitumen and has a molecular weight of at least about 300 prior to incorporation into said composition,
- said steric stabilizer maintaining dispersed particles of said particulate phase spaced from each other in said liquid phase, so as to inhibit separation of said particulate phase from said liquid phase by progressive coalescence of dispersed particles.
A composition for forming a stable dispersion of particulate polyolefin in a continuous bitumen phase, which comprises:
- a pro-steric stabilizer dissolved in bitumen and comprising a bitumen-compatible stabilizer segment which is a functionalized diene bonded to an olefinic polymer-compatible stabilizer segment which is a functionalized olefinic polymer, and an unfunctionalized polydiene which is soluble in or compatible with the bitumen and which has a molecular weight of at least about 300 prior to dissolution in bitumen.
A method of forming a stable composition, which comprises:
- dispersing an olefinic polymer in a continuous bitumen phase in which said olefinic polymeric material is insoluble to form a dispersion containing small particles of said olefinic polymer by contacting the olefinic polymer with the bitumen at a temperature above the fusion temperature of the olefinic polymer in the presence of steric stabilization forming components comprising a first individual component comprising a functionalized olefinic polymer for anchoring to the particulate phase, a second individual component different from said first component soluble in said liquid phase which is a functionalized diene, and an unfunctionalized polydiene which is soluble in or compatible with the bitumen and which has a molecular weight of at least about 300, and
- effecting chemical bonding between said steric stabilizer forming components and bonding to said particulate olefinic polymer to form a steric stabilizer in the form of an envelope surrounding and anchored to each particle in the particulate phase and comprising a cross-linked structure compatible with the liquid phase to maintain said particulate phase spaced apart from each other in said liquid phase.
A method of forming a bituminous composition, which comprises:
- (a) dissolving a functionalized diene in bitumen,
- (b) dispersing a functionalized olefinic polymer in said bitumen,
- (c) dissolving an unfunctionalized polydiene having a molecular weight of at least about 300 in the bitumen,
- (d) reacting said functionalized olefinic polymer and said functionalized diene so as to bind one end of said olefinic polymer to said diene;
- and
- (e) partially cross-linking said unfunctionalized polydiene with the functionalized diene and itself.
Dependencies are inferred from the claim text.