Grafted fluoroelastomers
AssigneeDuPont Performance Elastomers L.L.C.
InventorsPatrick Luigi Paglia, Walter Werner Schmiegel
Life of this patent
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Abstract
Polyhydroxy curable fluoroelastomers that are substantially free of nucleophilic endgroups are grafted with a monophenol having at least one pendant group. The resulting grafted fluoroelastomers retain most of the properties of the original elastomers including excellent pre-vulcanization characteristics, while incorporating pendant groups which may be used for further modification, crosslinking or for changing the physical properties (e.g. Tg) of the fluoroelastomer.
Claims12
A process for making a grafted fluoroelastomer, said process comprising:
- a) mixing in the bulk i) a polyhydroxy curable fluoroelastomer gum, said fluoroelastomer being substantially free of nucleophilic endgroups with ii) a monophenol having a pendant group, iii) an accelerator and iv) an acid acceptor to form a graftable fluoroelastomer composition;
- and
- b) heating said graftable composition at a temperature between 80° C. and 250° C., thereby producing a grafted fluoroelastomer having a plurality of pendant groups bonded to carbon atoms on said grafted fluoroelastomer through monophenols, said grafted fluoroelastomer being substantially free of nucleophilic endgroups and having a Mooney viscosity, ML(1+18) at 135° C., of less than 160.
A process for making a grafted fluoroelastomer, said process comprising:
- mixing in the bulk, at a temperature between 80° C. and 250° C., i) a polyhydroxy curable fluoroelastomer gum, said fluoroelastomer being substantially free of nucleophilic endgroups with ii) a monophenol having a pendant group, iii) an accelerator and iv) an acid acceptor to form a grafted fluoroelastomer having a plurality of pendant groups bonded to carbon atoms on said grafted fluoroelastomer through monophenols, said grafted fluoroelastomer being substantially free of nucleophilic endgroups and having a Mooney viscosity, ML(1+18) at 135° C., of less than 160.
A process for making a grafted fluoroelastomer from a polyhydroxy curable fluoroelastomer gum, said process comprising:
- a) mixing in the bulk, at a temperature between 80° and 250° C., i) a polyhydroxy curable fluoroelastomer gum, said fluoroelastomer being substantially free of nucleophilic endgroups, with ii) an accelerator and iii) an acid acceptor, in the absence of a grafting agent, to form an unsaturated fluoroelastomer;
- b) mixing i) said unsaturated fluoroelastomer composition with ii) a monophenol having a pendant group, iii) an accelerator and iv) an acid acceptor to form a graftable composition;
- and
- c) heating said graftable composition at a temperature between 80° C.-250° C., thereby producing a grafted fluoroelastomer having a plurality of pendant groups bonded to carbon atoms through monophenols, said grafted fluoroelastomer being substantially free of nucleophilic endgroups and having a Mooney viscosity, ML(1+18) at 135° C., of less than 160.
Dependencies are inferred from the claim text.