Fiber-reinforced thermoplastic vulcanizates
A thermoplastic vulcanizate comprising of a dynamically-cured rubber; and a thermoplastic phase, where the thermoplastic phase includes fiber and the reaction product of a methylene donor and a methylene acceptor. The thermoplastic phase could include a functionalized thermoplastic resin.
1. A method of forming a fiber-reinforced thermoplastic vulcanizate, the method comprising:
dynamically curing a rubber while the rubber is undergoing mixing with a thermoplastic resin to form a thermoplastic vulcanizate feedstock; and
introducing fiber, a methylene donor, a methylene acceptor, and optionally a functionalized thermoplastic resin, with the thermoplastic vulcanizate feedstock to form the fiber-reinforced thermoplastic vulcanizate;
wherein nylon is not added in either the dynamically curing step or the introducing step.
2. The method of claim 1 , where a functionalized thermoplastic is introduced with the thermoplastic vulcanizate stock or with the reinforced thermoplastic vulcanizate.
3. The method of claim 2 , where said step of introducing includes mixing the fiber, the methylene donor, the methylene acceptor, and the functionalized thermoplastic, with the thermoplastic vulcanizate feedstock at a temperature above the melt temperature of the thermoplastic vulcanizate feedstock.
4. The method of claim 3 , where the mixing occurs at a temperature of from about 170° C. to about 220° C.
5. The method of claim 2 , where said step of introducing includes introducing at least 1% and up to 50% by weight fiber based upon the total weight of the fiber-reinforced thermoplastic vulcanizate.
6. The method of claim 2 , where said step of introducing includes introducing at least 4 and up to 20% by weight functionalized thermoplastic resin based upon the total weight of the fiber-reinforced thermoplastic vulcanizate.
7. The method of claim 2 , where said step of introducing includes introducing at least 0.3 and up to 4% by weight methylene donor based upon the total weight of the fiber-reinforced thermoplastic vulcanizate.
8. The method of claim 2 , where said step of introducing includes introducing at least 0.5 and up to 6% by weight methylene acceptor based upon the total weight of the fiber-reinforced thermoplastic vulcanizate.
9. The method of claim 2 , farther comprising the step of aligning the fibers within the thermoplastic vulcanizate.
10. The method of claim 2 , further comprising the step of introducing an unfunctionalized thermoplastic to the thermoplastic vulcanizate feedstock.
11. The method of claim 1 , wherein the rubber is ethylene-propylene rubber.
12. The method of claim 1 , wherein the thermoplastic resin is a propylene-based polymer.