The invention relates to the use of chopped fibers in thermoplastic composite compounds, and in particular to thermoplastic fluoropolymer compounds. The fluoropolymer matrix contains thermoplastic fluoropolymers that have been grafted with a carboxylic polar functionality, such as KYNAR ADX® polymer from Arkema. The chopped fiber—grafted fluoropolymer composite has increased tensile and flexural strength compared to fluoropolymer compounds that contain no grafted carboxylic grafted fluoropolymer.