Toughened polyolefin nanocomposites using silane functionalized polyolefins
A method of forming a polyolefin-filler hybrid comprising combining vinyl/vinylidene-terminated polyolefin (VTP) and halosilane to form a silane functionalized polyolefin, followed by combining the silane functionalized polyolefin with a hydroxyl-containing filler, and/or combining the silane functionalized polyolefin with water and combining with hydroxyl-containing filler; to form a polyolefin-filler hybrid.
1. A method of forming a polyolefin-filler hybrid comprising:
a) combining vinyl/vinylidene-terminated polyolefin (VTP) and halosilane to form a silane functionalized polyolefin, followed by:
(i) combining the silane functionalized polyolefin with a hydroxyl-containing filler, and/or
(ii) combining the silane functionalized polyolefin with water and combining with the hydroxyl-containing filler;
b) recovering a polyolefin-filler hybrid;
wherein a solvent is also combined in steps (i) and/or (ii) having a dielectric constant within a range from 2.0 to 10.0 at 20° C.
2. The method of claim 1 , wherein the vinyl/vinylidene-terminated polyolefin has a molecular weight distribution (Mw/Mn) of less than 4.0.
3. The method of claim 1 , wherein the vinyl/vinylidene-terminated polyolefin has a weight average molecular weight (Mw) within the range from 3,000 g/mole to 50,000 g/mole.
4. The method of claim 1 , wherein the polyolefin-filler hybrid has a grafting density within the range from 0.01 chain/nm 2 to 0.16 chain/nm 2 .
5. The method of claim 1 , wherein the VTP and halosilane are combined with a vinylsiloxane/metal catalyst at a temperature of at least 90° C.
6. The method of claim 5 , wherein after combining the catalyst, additional halosilane is combined and maintained at a temperature of at least 90° C. for at least 5 hours.
7. The method of claim 1 , wherein the combining of the hydroxyl-containing filler is also at a temperature of at least 90° C. for at least an additional 5 hours.
8. The method of claim 1 , wherein the silane functionalized polyolefin is a silane functionalized polypropylene, a polyethylene, or an ethylene-propylene copolymer.
9. The method of claim 1 , wherein the halosilane is selected from the group consisting of trichlorosilane, tribromoasilane, chlorodimethylsilane, bromodimethylsilane, dibromomethylsilane, dichloromethylsilane, and combinations thereof.
10. The method of claim 1 , wherein the solvent used in steps (i) and/or (ii) has a dielectric constant within a range from 2.5 to 10.0 at 20° C.
11. The method of claim 1 , wherein the hydroxyl-containing filler is selected from the group consisting of silicates, aluminates, borates, silica, quartz, glass, alumina, alumino-silicates, silicon, copper, copper oxide, tin, tin oxide, talc, iron oxide, chromium oxide, steel, iron, nickel, zinc, lead, surface treated or oxidized carbon, and calcium carbonate, and mixtures thereof.
12. The method of claim 1 , where the hydroxyl-containing filler has an average particle diameter of less than 0.1 μm.
13. The method of claim 1 , further comprising combining the polyolefin-filler hybrid with at least one polyolefin selected from polypropylene, polyethylene, and ethylene-propylene copolymer to form a polyolefin nanocomposite.