Study On Modification Of Melamine Formaldehyde Fiber

Melamine formaldehyde fiber is also called melamine,which was prepared by condensation polymerization of paraformaldehyde,and was spun and heated treatment for as-spun fiber.The fiber shows a high-temperature resistant to acid and alkali.The fiber has a well conducts electricity after process at high temperature because of the high contain nitrogen,which can be widely used in the energy field.But it is not easy to synthesis the melamine formaldehyde resin,and to solve the problems such as the shortage of storage time,and brittle fracture.In this article.A method was suggested that the modification of melamine formaldehyde fiber was prepared by wet-spinning melamine-formaldehyde resinr and heat-curing,and a series of analysis and characterization was applied.(1)In this paper,melamine resin was synthesized between melamine and formaldehyde.The polyvinyl alcohol is a modifier.The fiber was cured at the heat treatment temperature after wet spinning of resin.Melamine formaldehyde fiber structure and performance were showed that the melamine formaldehyde fiber toughness is better,when the quality concentration of polyvinyl alcohol is 12 %,the molar ratio of melamine and paraformaldehyde is 1:1.5.The tensile strength and the elongation at break increased to 180 MPa,and 8 %,respectively.TG showed that the decomposition temperature increase to340 ? and the char yield of the melamine fiber is 20 % at 800 ?.(2)The melamine fiber was modified by the phenol,and a series of analyses were carried out on the modified melamine formaldehyde fiber.The results showed that the melamine formaldehyde fiber was successful modified by phenol.The tensile strength and the elongation at break reached at 150 MPa and 20 %,respectively.The decomposition temperature was maintained at 340 ? in nitrogen atmosphere,and the char yield reached at58 % at 800 ?.(3)The melamine fiber was prepared by the melamine resin modified by the urea.The results showed that the melamine formaldehyde fiber was successfully prepared.The tensile strength of the fiber was increased to 260 MPa,the elongation at break was to 20 %.Thedecomposition temperature was maintained at 340 ? in nitrogen atmosphere,and the char yield decreased to 25 % at 800 ?.The results showed that the modified melamine resin was synthesized by the copolymerization,and a series of modified melamine formaldehyde fiber was obtained by wet spinning and heat curing.Based on the reducing of the functionality of molecule.The difficulties of melamine resin synthesis was solved.The storage time of resin was been extended to 12 d,and the toughness of the melamine formaldehyde fiber was been increased.The tensile strength and the elongation at break were increased to 260 MPa and of 20 %,respectively.By contrast,the elongation of melamine formaldehyde fiber modified by phloroglucinol BG was 7.2 %,13 %.The advantage of using modifier in this paper can be seen from the elongation.