Abstract: Disclosed is a diamine compound represented by Formula (1), in which R1, R2, R3, R4, R5, X1, X2, X3, X4, m, n, a, b, c, and d are as defined herein. Also disclosed are a method for manufacturing the diamine compound, a composition including the diamine compound having a (chain alkoxy-methylene) phenyl group or a (hydroxyl-methylene) phenyl group, and a polymer including the (chain alkoxy-methylene) phenyl group or the (hydroxyl-methylene) phenyl group.

Abstract: Disclosed is a diamine compound represented by Formula (1), in which R1, R2, R3, R4, R5, X1, X2, X3, X4, m, n, a, b, c, and d are as defined herein. Also disclosed are a method for manufacturing the diamine compound, a composition including the diamine compound having a (chain alkoxy-methylene) phenyl group or a (hydroxyl-methylene) phenyl group, and a polymer including the (chain alkoxy-methylene) phenyl group or the (hydroxyl-methylene) phenyl group.

Abstract: A pencil sharpener includes a main unit including a main body and a pencil sharpening device, and an outer shell detachably sleeved on the main body. The main body includes a bottom base, a supporting seat and an engaging member. The supporting seat includes a surrounding wall extending upwardly from a periphery of the bottom base, and a top wall connected to a top end of the surrounding wall. The pencil sharpening device is detachably disposed between the bottom base and the top wall. The engaging member is fixedly disposed on the surrounding wall. The outer shell includes an inner surface frictionally abutting against the engaging member. The outer shell and the surrounding wall cooperatively define a shaving collecting room.

Abstract: A pitching training device includes a connecting element and a pocket. The connecting element alternatively attached to the wrist of a throwing hand of a thrower. The pocket includes open and closed ends disposed at two opposite ends thereof. The open end of the pocket is connected with the connecting element and allowing the throwing hand and a ball gripped in the palm of the throwing hand into the pocket. The closed end of the pocket limits the thrown ball that cannot move to outside of the pocket.