Polybutadiene graft copolymers as coupling agents for carbon black and silica dispersion in rubber compounds
Coupling agents useful for preparing vulcanized composition with filers such as silica and carbon black are provided. The coupling agents include fluorine substituted styrene compounds and styrene compounds containing a hydrocarbyloxysilane functional group. The coupling agents may be grafted onto polydiene polymers or added into a vulcanizable composition as an oligomer. The use of one or both of fluorine substituted styrene compounds and styrene compounds containing a hydrocarbyloxysilane functional group may improve the strength, rolling resistance, and/or cure rate of a vulcanized polymer compared to a vulcanized polymer without a coupling agent.
1. A vulcanizable composition comprising:
a curative;
a filler comprising carbon black and silica; and
a polydiene grafted with a mer unit derived from the polymerization of a fluorine substituted styrene compound and a mer unit derived from the polymerization of styrene compound containing a hydrocarbyloxysilane functional group, where the styrene compound containing a hydrocarbyloxysilane functional group is defined by the formula:
where R 2 is a divalent organic group and each R 3 is individually a monovalent organic group.
2. The vulcanizable composition of claim 1 , where R 2 is hydrocarbon group with from 1 to about 18 carbon atoms.
3. The vulcanizable composition of claim 1 , where each R 3 is individually a hydrocarbon group with from 1 to about 18 carbon atoms.
4. The vulcanizable composition of claim 2 , where each R 3 is individually a hydrocarbon group with from 1 to about 18 carbon atoms.
5. The vulcanizable composition of claim 1 , where the fluorine substituted styrene compound is defined by the formula:
where R 1 is a monovalent organic group and n is an integer selected from 0 and 1.
6. The vulcanizable composition of claim 1 , where the fluorine substituted styrene compound is defined by the formula:
7. The vulcanizable composition of claim 1 , further comprising one or more synthetic or natural rubbers.
8. The vulcanizable composition of claim 1 , further comprising:
a styrene-diene copolymer.
9. A tire or tire component comprising the reaction product of the vulcanizable composition of claim 1 .
10. A vulcanizable composition comprising:
a curative;
a filler comprising carbon black and silica; and
a polydiene grafted with a mer unit derived from the polymerization of a fluorine substituted styrene compound and a mer unit derived from the polymerization of styrene compound containing a hydrocarbyloxysilane functional group, where the styrene compound containing a hydrocarbyloxysilane functional group is defined by the formula:
where each R 3 is individually monovalent organic group.
11. The vulcanizable composition of claim 10 , where each R 3 is individually a hydrocarbon group with from 1 to about 18 carbon atoms.