The Compression Molding of N, N'-Dipropargylfumaramide Dimer

Abstract

Network polymers which have highly ordered and dense crosslinkages are expected to be a new material with good mechanical properties. In order to obtain these polymers, a N, N'-dipropargylfumaramide dimer (FADD) was prepared to form an ordered and dense crosslinkage in the solid state, and their molding under hydrostatic pressure was studied.
( 1 ) This diacetylene compou nd has two functional groups, a diacetylene moiety and a terminal ethynyl group. These unsaturated groups are highly reactive toward thermally induced solid state reaction. IR spectra show that the two-step reaction composed of the polymerization of the diacetylene moieties and the reaction of the ethynyl groups occures in the solid state. Consequently crosslinking in this compound seems to occur through the two step reaction. The X-ray scattering pattern of the obtained polymer indicates that the crystalline structure is highly disordered. However, the solid-state reaction under high pressure (650 MPa) yields rather ordered and dense network polymers.
( 2 ) The powder compression molding of the com pound was investigated. The properties of moldings highly depend on the applied pressure and the molding temperature. These moldings are isotropic and have excellent properties, such as Young's modulus, ultrasonic velosity, thermal conductivity. The maximum value of Young's moduli reached 15.5 GPa. The thermal conductivities of the moldings are about two or three times larger than those of commodity polymers.