Liquid thermoplastic resin and pultrusion method

A method for making composite structures made of thermoplastic nanocomposite/fiber-reinforced composite, comprising the following steps:

• a. forming a liquid resin mixture comprising:
• 70-90 wt. % methyl methacrylate monomer containing a polymerization inhibitor, 10-30 wt. % polymeric viscosity-promoting agent, 0.1-10 wt. % nano clay, and an internal lubricant;
• b. removing said polymerization inhibitor from said methyl methacrylate monomer;
• c. mixing a nitro compound retarder into said liquid resin mixture after removing said polymerization inhibitor to stabilize said liquid resin against premature polymerization and thereby to form a thermoplastic liquid resin;
• d. selecting a pultrusion injection die system including a pultrusion injection die defining a mold cavity, a braid fiber delivery system, a liquid resin impregnation system, a puller configured to pull impregnated fibers through said pultrusion injection die, and a cutter configured to cut a cured composite to a desired length;
• e. impregnating a plurality of braided fibers with said thermoplastic liquid resin using said liquid resin impregnation system to form wetted braided fibers;
• f. delivering said wetted braided fibers into said mold cavity of said pultrusion injection die;
• g. applying pressure and heat to said wetted braided fibers within said mold cavity to polymerize said thermoplastic liquid resin and form a fiber-reinforced composite;
• h. cooling said fiber-reinforced composite and thereafter pulling said cooled fiber-reinforced composite from said pultrusion injection die using said puller;
• and
• i. cutting said fiber-reinforced composite into desired lengths using said cutter.