A continuous fiber composite is described and methods for forming the continuous fiber composite. The continuous fiber composite includes a plurality of unidirectionally aligned continuous fibers embedded within a polyarylene sulfide polymer. The continuous fiber composite includes a very high loading of continuous fibers, for instance greater than about 40% by weight of the continuous fiber composite. The continuous fiber composite is formed by reacting a starting polyarylene sulfide with a reactively functionalized disulfide compound in a melt processing unit. Reaction between the starting polyarylene sulfide and the reactively functionalized disulfide compound leads to formation of a reactively functionalized polyarylene sulfide. Upon embedding of the continuous fibers into the reactively functionalized polyarylene sulfide, the reactivity of the polyarylene sulfide can enhance adhesion between the polyarylene sulfide polymer and the fibers.