A process for making a fiber composite involving: (a) providing a natural fiber; (b) providing a matrix material produced by a radical polymerization reaction of: (i) a monomer selected from the group consisting of ring opening products of epoxidized fatty compounds with olefinically unsaturated carboxylic acids, and (ii) a comonomer selected from the group consisting of olefinically unsaturated carboxylic acids; (c) providing a radical initiator; and (d) conducting the radical polymerization reaction of (i) and (ii) in the presence of the natural fiber so that the matrix material envelops the natural fiber, thus producing the fiber composite.