Coated proppants can include a plurality of particles and one or more cured resin at least partially encasing or coating each of the particles. The cured resin, prior to curing, can be or include one or more treated aldehyde-based resins that can include one or more aldehyde-based resins and one or more polyamines. The polyamine can be or include one or more aromatic polyamines, one or more poly(C2-C5 alkylene) polyamines, or a mixture thereof. The coated proppant can have a dry crush strength of about 0.1 wt % to about 3 wt % at a pressure of about 55.2 MPa, based on the Proppant Crush Resistance Test Procedure under ISO 13503-2:2011.