Method for treating reinforcing fibre and method for producing a reinforced composite article from the treated fibre
The present invention relates to a reinforced composite material and a method for its production. The composite material comprises at least one cured resin having a reinforcing material. Preferably the reinforcing material is a plurality of glass fibers which are treated such that the properties of the interphase substantially surrounding each fiber are substantially equivalent to those of the bulk cured resin. The fiber treatment may be selected from the group consisting of a polymeric coating, a hydrophilic surface coating, a surface coating of a free radical inhibitor, or a reduction in the total surface area of the fibers. The reinforced composite material of the invention provides improved long-term mechanical properties compared to traditional glass fiber reinforced materials.
1. A reinforced composite material, comprising:
i) a plurality of reinforcing fibers treated with a hydrophilic surface coating comprising the product of a vinyl functional silane coupling agent reacted with a polyol;
ii) at least one cured resin; and
iii) at least one interphase defined by the at least one cured resin adjacent to and substantially surrounding at least one reinforced fiber of the plurality of reinforcing fibers;
wherein the hydrophilic surface coating of said plurality of reinforcing fibers results in the at least one interphase having one or more properties substantially equivalent to those of the bulk cured resin.
2. The reinforced composite material of claim 1 , wherein:
a) the coupling agent comprises methacryloxypropyl-trimethoxysilane, vinylbenzylaminoethylaminopropyl-trimethoxysilane, or vinyl-tris(acetoxy) silane; and
b) the polyol comprises a tri-hydroxy compound or a tetra-hydroxy compound.
3. The reinforced composite material of claim 2 , wherein the tri-hydroxy compound is trimethylolpropane.
4. The reinforced composite material of claim 2 , wherein the tetra-hydroxy compound is pentaerythritol.
5. The reinforced composite material of claim 1 , wherein the one or more properties of said at least one interphase comprises:
i) a mechanical property, comprising strength, toughness, or brittleness; or
ii) a physical or chemical property, comprising density, cross-link density, chemical resistance, molecular weight, or degree of crystallinity.
6. The reinforced composite material of claim 1 , wherein the reinforcing fiber of the plurality of reinforcing fibers is a glass fiber having a length of between 100 and 1000 microns.
7. The reinforced composite material of claim 1 , wherein the at least one cured resin is a polymer-modified resin.
8. The reinforced composite material of claim 7 , wherein the polymer-modified resin comprises between 5 to 50% w/w of the polymer.
9. The reinforced composite material of claim 8 , wherein the polymer-modified resin has flexural toughness greater than 3 Joules according to a standard flexure test using a test piece of 100 mm length, 15 mm width, and 5 mm thickness.
10. The reinforced composite material of claim 9 , wherein the flexural toughness is greater than 3 Joules for up to 5 years.
11. The reinforced composite material of claim 7 , wherein the polymer-modified resin has one or more of the following properties: tear resistance, strength, toughness, or resistance to embrittlement.
12. The reinforced composite material of claim 1 , wherein the reinforced composite material comprises one or more of the following:
i) a flexural modulus of greater than about 3.1 GPa;
ii) a flexural stress of greater than about 120 MPa; or
iii) an elongation at break of greater than about 2%.
13. The reinforced composite material of claim 1 , wherein the hydrophilic surface coating of the plurality of reinforcing fibers:
a) reduces catalyzation of resin polymerization in the at least one interphase when compared to an untreated fiber; or
b) reduces embrittlement of said at least one interphase when compared to an untreated fiber.
14. A liquid curable composite, comprising:
i) a plurality of reinforcing fibers treated with a hydrophilic surface coating comprising the product of a vinyl functional silane coupling agent reacted with a polyol, wherein the reinforcing fiber of the plurality of reinforcing fibers is a glass fiber having a length of between 100 and 1000 microns; and
ii) at least one curable resin;
wherein when cured, the cured resin adjacent to and substantially surrounding at least one reinforced fiber of the plurality of reinforcing fibers defines at least one interphase having one or more properties substantially equivalent to those of the bulk cured resin.
15. The liquid curable composite of claim 14 , wherein:
a) the coupling agent comprises methacryloxypropyl-trimethoxysilane, vinylbenzylaminoethylaminopropyl-trimethoxysilane, or vinyl-tris(acetoxy) silane; and
b) the polyol comprises a tri-hydroxy compound or a tetra-hydroxy compound.
16. The liquid curable composite of claim 15 , wherein the tri-hydroxy compound is trimethylolpropane.
17. The liquid curable composite of claim 15 , wherein the tetra-hydroxy compound is pentaerythritol.
18. The liquid curable composite of claim 14 , further comprising water.
19. The liquid curable composite of claim 14 , wherein the hydrophilic surface coating of the plurality of reinforcing fibers:
a) reduces catalyzation of resin polymerization in the at least one interphase when compared to an untreated fiber; or
b) reduces embrittlement of said at least one interphase when compared to an untreated fiber.
20. A reinforced composite material prepared by curing the liquid curable composite of claim 14 .