Polymer composite strengthened with carbon fiber surface-modified by plasma treatment and method for producing polymer composite

A method for producing an engineering plastic composite, comprising:

• performing a plasma treatment using a reactive gas including a carbon fiber bundle to modify a surface of the carbon fiber bundle and attach a functional group;
• and
• mixing the modified carbon fiber with an engineering plastic to constitute a composite,
• wherein the plasma treatment is performed in a plasma apparatus which is disposed inside a vacuum container and includes a top electrode and a bottom electrode disposed to face each other by a capacitively-coupled hydrogen plasma which is generated by RF power which places the carbon fiber bundle at the bottom electrode, heats the bottom electrode, and receives and provides a hydrogen gas to the top electrode,
• wherein a reaction temperature of the bottom electrode is between 300 and 400 degrees Celsius, and
• wherein the surface of the carbon fiber bundle is modified by the plasma treatment to transform an SP2 bond of graphite structure to an SP3 bond of diamond structure.