Fiber-reinforced composites made with thermoplastic resin compositions and reactive coupling fibers

Abstract

Methods of making fiber-resin compositions are described. The methods may include the providing of a thermoplastic resin to an extruder, where the thermoplastic resin may include at least one reactive moiety capable of forming a covalent bond with a coupling agent on a plurality of reactive fibers. The methods may further include combining the thermoplastic resin with the plurality of reactive fibers also supplied to the extruder. The reactive fibers are sized with the coupling agent that reacts with the thermoplastic resin to form the fiber-resin composition, which may be extruded from the extruder. Methods of making fiber-reinforced composite articles from the fiber-resin composition are also described.

What is claimed is: 
     
         1 . A fiber-resin composition for making a fiber-reinforced article, the fiber-resin composition comprising:
 glass fibers comprising a coupling agent bonded to the glass fibers; and   a thermoplastic resin selected from the group consisting of polybutylene terephthalate polymers, thermoplastic polyurethane polymers, polystyrene-co-maleic anhydride polymers, maleated polypropylene polymers, and polyhydroxy-ethyl methacrylate polymers,   wherein the coupling agent comprises:
 (i) a silicon-containing moiety covalently bonded to the glass fibers, 
 (ii) a reactive isocyanate moiety capable of forming the covalent bond with at least one reactive moiety of the thermoplastic resin when a blocking group is released from the reactive isocyanate moiety, and 
 (iii) a linking moiety selected from the group consisting of an alkyl linker, and aryl linker, and an alkyl-aryl linker, wherein the linking moiety covalently bonds the silicon-containing moiety and the reactive isocyanate moiety together in the coupling agent. 
   
     
     
         2 . The fiber-resin composition of  claim 1 , wherein the glass fibers have a length of less than 0.5 inches. 
     
     
         3 . The fiber-resin composition of  claim 1 , wherein the glass fibers have a length ranging from 0.5 inches to 2 inches. 
     
     
         4 . The fiber-resin composition of  claim 1 , wherein the glass fibers comprise at least one type of glass selected from the group consisting of E-glass, A-glass, C-glass, S-glass, ECR-glass, and T-glass. 
     
     
         5 . The fiber-resin composition of  claim 1 , wherein the fiber resin composition further comprises one or more type of fibers selected from the group consisting of ceramic fibers, carbon fibers, metal fibers, and organic polymer fibers. 
     
     
         6 . The fiber-resin composition of  claim 1 , wherein the silicon-containing moiety has a formula of: 
       
         
           
           
               
               
           
         
       
       wherein R 1 , R 2 , and R 3  may be the same or different, and each may represent an alkyl group, an aryl group, an alkoxy group, a halogen, a hydroxyl group, or a cyclic structure. 
     
     
         7 . The fiber-resin composition of  claim 1 , wherein the reactive isocyanate moiety has a formula of: 
       
         
           
           
               
               
           
         
       
       wherein BLK represents the blocking group that is reversibly bonded to a carbon atom on the reactive isocyanate moiety. 
     
     
         8 . The fiber-resin composition of  claim 7 , wherein the blocking group is selected from the group consisting of oximes, lactams, and organosilicon compounds. 
     
     
         9 . The fiber-resin composition of  claim 8 , wherein the oximes are selected from the group consisting of methyl ethyl ketoxime, acetone oxime, and cyclohexanone oxime. 
     
     
         10 . The fiber-resin composition of  claim 8 , wherein the lactams comprise ε-caprolactam. 
     
     
         11 . A fiber-reinforced article comprising:
 glass fibers; and   thermoplastic polymers selected from the group consisting of polybutylene terephthalate polymers, thermoplastic polyurethane polymers, polystyrene-co-maleic anhydride polymers, maleated polypropylene polymers, and polyhydroxy-ethyl methacrylate polymers, wherein the thermoplastic polymers are bonded to the glass fibers by a coupling agent that is covalently bonded to both the glass fibers and the thermoplastic polymers,   wherein the coupling agent comprises:
 (i) a silicon-containing moiety covalently bonded to the glass fibers, 
 (ii) a reactive isocyanate moiety capable of forming the covalent bond with at least one reactive moiety of the thermoplastic polymers when a blocking group is released from the reactive isocyanate moiety, and 
 (iii) a linking moiety selected from the group consisting of an alkyl linker, and aryl linker, and an alkyl-aryl linker, wherein the linking moiety covalently bonds the silicon-containing moiety and the reactive isocyanate moiety together in the coupling agent. 
   
     
     
         12 . The fiber-reinforced article of  claim 11 , wherein the glass fibers have a length of less than 0.5 inches. 
     
     
         13 . The fiber-reinforced article of  claim 11 , wherein the glass fibers have a length ranging from 0.5 inches to 2 inches. 
     
     
         14 . The fiber-reinforced article of  claim 11 , wherein the article is selected from the group consisting of a turbine blade, a vehicle part, an appliance part, and a container. 
     
     
         15 . A system for making a fiber-reinforced article, the system comprising:
 a molten polymer amalgam comprising:
 glass fibers; and 
 thermoplastic polymers selected from the group consisting of polybutylene terephthalate polymers, thermoplastic polyurethane polymers, polystyrene-co-maleic anhydride polymers, maleated polypropylene polymers, and polyhydroxy-ethyl methacrylate polymers, wherein the thermoplastic polymers are bonded to the glass fibers by a coupling agent that is covalently bonded to both the glass fibers and the thermoplastic polymers, 
 wherein the coupling agent used to bond the glass fibers and the thermoplastic polymers originally comprised: 
   (i) a silicon-containing moiety covalently bonded to the glass fibers,   (ii) a reactive isocyanate moiety capable of forming the covalent bond with at least one reactive moiety of the thermoplastic polymers when a blocking group is released from the reactive isocyanate moiety, and   (iii) a linking moiety selected from the group consisting of an alkyl linker, and aryl linker, and an alkyl-aryl linker, wherein the linking moiety covalently bonds the silicon-containing moiety and the reactive isocyanate moiety together in the coupling agent; and   a molding machine that accepts the molten amalgam and molds it into the fiber-reinforced article.   
     
     
         16 . The system of  claim 15 , wherein the supply of fibers are short glass fibers having a length of less than 0.5 inches. 
     
     
         17 . The system of  claim 15 , wherein the supply of fibers are long glass fibers having a length ranging from 0.5 inches to 2 inches. 
     
     
         18 . The system of  claim 15 , wherein the blocking group is selected from the group consisting of oximes, lactams, and organosilicon compounds. 
     
     
         19 . The system of  claim 15 , wherein the blocking group comprises ε-caprolactam. 
     
     
         20 . The system of  claim 15 , wherein the molding machine is selected from the group consisting of an injection molding machine and a compression molding machine.